Filed Pursuant to Rule 424(b)(5)

Registration No. 333-255340

CALCULATION OF REGISTRATION FEE

Prospectus supplement

(To prospectus dated April 19, 2021)

$750,000,000

Zai Lab Limited

4,776,000 American depositary shares, representing 4,776,000 ordinary shares

224,000 ordinary shares

We are offering an aggregate of 4,776,000 American Depositary Shares, or ADSs, and 224,000 ordinary shares. Each ADS represents one ordinary share, par value US$0.00006 per share, of Zai Lab Limited.

Our ADSs are listed on the Nasdaq Global Market under the symbol “ZLAB.” On April 20, 2021, the last reported sale price of the ADSs on the Nasdaq Global Market was $150.77 per ADS. Investors have elected to receive 224,000 ordinary shares in lieu of ADSs in this offering, which will be settled in Hong Kong dollars, based upon each ADS representing one ordinary share and an exchange rate of HK$7.7613 to US$1.00, the spot rate of exchange at the time of pricing. Our ordinary shares are listed on The Stock Exchange of Hong Kong Limited (the “Hong Kong Stock Exchange”) pursuant to Chapter 19C and Chapter 18A of the Hong Kong Stock Exchange Listing Rules (“Listing Rules”) under the stock code “9688.” On April 19, 2021, the last reported sale price of the ordinary shares on the Hong Kong Stock Exchange was HK$1,294.00 per ordinary share.

Investing in the ADSs and/or ordinary shares involves a high degree of risk. See the “Risk factors” beginning on page S-8 of this prospectus supplement, in any accompanying prospectus and in any documents incorporated by reference into this prospectus supplement.

Neither the United States Securities and Exchange Commission nor any state securities commission or any other regulatory body has approved or disapproved of these securities or determined if this prospectus supplement is truthful or complete. Any representation to the contrary is a criminal offense.

PRICE $150.00 PER ADS

PRICE HK$1,164.20 PER ORDINARY SHARE

The underwriters have an option to purchase up to an aggregate of 716,400 additional ADSs from us at the public offering price, less underwriting discounts and commissions, within 30 days of the date of this prospectus supplement, which purchase will be settled only in ADSs.

The underwriters expect to deliver the ADSs against payment to the purchasers on or about April 23, 2021, on a “T+2” basis. The underwriters expect to deliver the ordinary shares against payment therefor through the facilities of the Central Clearing and Settlement System (“CCASS”) on or about April 28, 2021, on a “T+5” basis.

Guggenheim Securities

The date of this prospectus supplement is April 20, 2021.

Table of contents

You should rely only on the information contained or incorporated by reference into this prospectus supplement, the accompanying prospectus or any free writing prospectus we file with the United States Securities and Exchange Commission, or the SEC. We have not, and the underwriters have not, authorized any other person to provide you with different information. If anyone provides you with different or inconsistent information, you should not rely on such different or inconsistent information. We are not, and the underwriters are not, making an offer of the ADSs or ordinary shares in any jurisdiction where such offer is not permitted. You should not assume that the information contained or incorporated by reference into this prospectus supplement and the accompanying prospectus or in any free writing prospectus is accurate as of any date other than the respective dates thereof. Our business, financial condition, results of operations and prospects may have changed since those dates. Neither this prospectus supplement nor the accompanying prospectus constitutes an offer, or an invitation on our behalf or the underwriters to subscribe for and purchase, any of the ADSs or ordinary shares and may not be used for or in connection with an offer or solicitation by anyone, in any jurisdiction in which such an offer or solicitation is not authorized or to any person to whom it is unlawful to make such an offer or solicitation.

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Under Rule 15c6-1 under the Exchange Act, trades in the secondary market generally are required to settle in two business days unless the parties to any such trade expressly agree otherwise. Accordingly, purchasers who wish to trade the ordinary shares on any date prior to the second business day before delivery thereof will be required, by virtue of the fact that the ordinary shares will settle in T+5, to specify an alternative settlement cycle at the time of any such trade to prevent failed settlement. Purchasers of the ordinary shares who wish to trade the ordinary shares prior to their delivery should consult their own advisors.

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About this prospectus supplement

This prospectus supplement and the accompanying prospectus are part of an automatic shelf registration statement that we filed with the SEC, as a “well-known seasoned issuer” as defined in Rule 405 under the Securities Act of 1933, as amended, or the Securities Act. Under the shelf registration process, from time to time, we may offer and sell any combination of the securities described in the accompanying prospectus in one or more offerings. This document is in two parts. The first part is the prospectus supplement, which describes the specific terms of this offering of the ADSs and ordinary shares, and supplements information contained in the accompanying prospectus and certain documents incorporated by reference into the accompanying prospectus. The second part consists of the accompanying prospectus dated April 19, 2021 and included in the registration statement on Form S-3 filed with the SEC on April 19, 2021, which gives more general information about us and the securities we may offer from time to time under our shelf registration statement, some of which may not be applicable to this offering.

To the extent there is a conflict between the information contained in this prospectus supplement, on the one hand, and the information contained in the accompanying prospectus or any previously filed document incorporated by reference into this prospectus supplement or the accompanying prospectus, on the other hand, you should rely on the information in this prospectus supplement.

You should carefully read the accompanying prospectus, this prospectus supplement, the documents incorporated by reference in the accompanying prospectus and this prospectus supplement, and any free writing prospectus that we have authorized for use in connection with this offering, in their entirety before making an investment decision, together with additional information described below under the heading “Where you can find more information” and “Incorporation of documents by reference.”

In this prospectus supplement, unless otherwise indicated or unless the context otherwise requires:

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Cautionary statement concerning forward-looking statements

This prospectus supplement, the accompanying prospectus and the documents incorporated by reference herein and therein contain forward-looking statements. Forward-looking statements are neither historical facts nor assurances of future performance. Instead, they are based on our current beliefs, expectations and assumptions regarding the future of our business, future plans and strategies, our operational results and other future conditions. Forward-looking statements can be identified by words such as “aim”, “anticipate,” “believe,” “estimate,” “expect,” “intend,” “may,” “plan,” “predict,” “project,” “seek,” “target,” “potential,” “will,” “would,” “could,” “should,” “continue,” “contemplate” and other similar expressions, although not all forward-looking statements contain these identifying words. These forward-looking statements include all matters that are not historical facts. They appear in a number of places throughout this prospectus supplement, the accompanying prospectus and the documents incorporated herein by reference and include statements regarding our intentions, beliefs or current expectations concerning, among other things, our results of operations, financial condition, liquidity, prospects, growth, strategies and the industry in which we operate.

By their nature, forward-looking statements involve risks and uncertainties because they relate to events and depend on circumstances that may or may not occur in the future. We believe that these risks and uncertainties include, but are not limited to, those described in the “Risk Factors” section of this prospectus supplement, the accompanying prospectus and the documents incorporated herein, including the risks outlined under the heading “Risk Factors” in our Form 10-K, and therein by reference, which include, but are not limited to, the following:

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These factors should not be construed as exhaustive and should be read with the other cautionary statements in this prospectus supplement, the accompanying prospectus and the documents incorporated herein and therein by reference.

Although we base these forward-looking statements on assumptions that we believe are reasonable when made, we caution you that forward-looking statements are not guarantees of future performance and that our actual results of operations, financial condition and liquidity, and the development of the industry in which we operate may differ materially from those made in or suggested by the forward-looking statements contained in this prospectus supplement, the accompanying prospectus and the documents incorporated herein and therein by reference. In addition, even if our results of operations, financial condition and liquidity, and the development of the industry in which we operate, are consistent with the forward-looking statements contained in this prospectus and the documents incorporated herein by reference, those results or developments may not be indicative of results or developments in subsequent periods.

Given these risks and uncertainties, you are cautioned not to place undue reliance on these forward-looking statements. Any forward-looking statement that we make in this prospectus supplement, the accompanying prospectus and the documents incorporated herein and therein by reference speaks only as of the date of such statement. Comparisons of results for current and any prior periods are not intended to express any future trends or indications of future performance, unless specifically expressed as such, and should only be viewed as historical data.

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continue to pursue a strategy of growth and development by: (i) expanding our product candidate pipeline through global collaborations and corporate development activities; (ii) capitalizing on commercial opportunities for our approved products; and (iii) investing in our global pipeline by advancing our internally discovered novel therapeutics. We also plan to expand our collaborations with leading academic institutions in both the United States and Greater China. We believe that this strategy, supported by the above actions we have taken and will continue to take, will bring us closer to achieving our goal of becoming a leading global biopharmaceutical company.

The following table summarizes the status of our commercial products, as well as the status of product candidates that are under Priority Review by the NMPA:

 

Product		Indications		Regulatory Status		Commercial Rights		Partner
		1st line ovarian cancer 2nd line ovarian cancer		Launched in China, Hong Kong and Macau		China, Hong Kong and Macau
		Newly diagnosed and recurrent glioblastoma multiforme (GBM)		Launched in China, Hong Kong and Macau		China, Hong Kong, Macau and Taiwan
		4th line gastrointestinal stromal tumors (GIST)		Approved in China		China, Hong Kong, Macau and Taiwan
		Acute bacterial skin and skin structure infection (ABSSSI)   Community-acquired bacterial pneumonia (CABP)		Priority Review in China		China, Hong Kong, Macau and Taiwan

Our approved drug ZL-2306, or ZEJULA, is an oral, once-daily small molecule poly ADP ribose polymerase, or PARP, 1/2 inhibitor being developed and commercialized outside of China, Hong Kong and Macau by our partner, TESARO, Inc. (recently acquired by GlaxoSmithKline, or GSK). ZEJULA has the potential to be a differentiated drug for treatment across multiple solid tumor types in China, including ovarian and certain other types of cancer. In March 2017, ZEJULA received U.S. Food and Drug Administration, or FDA, marketing approval and in November 2017, it received European Commission marketing approval as a maintenance treatment for recurrent platinum-sensitive epithelial ovarian cancer. In April 2017, TESARO (now GSK) commercially launched the product in the United States under the commercial name ZEJULA. In October 2018, the Hong Kong Department of Health approved our application for ZEJULA in Hong Kong for adult patients with platinum-sensitive relapsed high grade serous epithelial ovarian cancer who are in a complete response or partial response to platinum-based chemotherapy. We began commercializing ZEJULA in Hong Kong in the fourth quarter of 2018. In China, our CTA for ZEJULA has been approved as a Category 1 drug by the NMPA across all indications that we aim to pursue. ZEJULA was also designated as a “National Sciences and Technology Major Project” by the Chinese government as part of a key initiative to strengthen local innovation. ZEJULA was approved and launched in Macau in June 2019. We launched ZEJULA in China in January 2020 after approval in December 2019 by the NMPA as a second-line maintenance treatment for women with recurrent platinum-sensitive ovarian cancer. In September 2020, ZEJULA was approved by the NMPA as a maintenance treatment for adult patients with advanced epithelial ovarian, fallopian tube or primary peritoneal cancer who are in a complete or partial response to first-line platinum-based chemotherapy. ZEJULA is the only PARP inhibitor approved by the FDA, the EMA and the NMPA for first-and second-line maintenance treatment for women with platinum-responsive advanced ovarian cancer regardless of biomarker status, such as BRCA mutations.

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Risk factors

An investment in the ADSs and/or ordinary shares involves significant risks. You should consider carefully all of the information in this prospectus supplement and the accompanying prospectus, including the risks outlined under the heading “Risk Factors” in our Form 10-K, which is incorporated by reference herein, and the other documents incorporated by reference herein and therein, and the risks and uncertainties described below, before making an investment in the ADSs and/or ordinary shares. Any of the following risks could have a material and adverse effect on our business, financial condition and results of operations. In any such case, the market price of the ADSs and/or ordinary shares could decline, and you may lose all or part of your investment.

Risks related to our ordinary shares, the ADSs and this offering

As a company listed under Chapter 19C and Chapter 18A, we adopt different practices as to certain matters as compared with many other companies listed on the Hong Kong Stock Exchange.

As we are listed under Chapter 19C and Chapter 18A of the Listing Rules, we will not be subject to certain provisions of the Listing Rules pursuant to Rule 19C.11, including, among others, rules on notifiable transactions, connected transactions, share option schemes, content of financial statements as well as certain other continuing obligations. In addition, in connection with the listing under Chapter 19C, we have applied for and obtained a number of waivers and/or exemptions from strict compliance with the Listing Rules, the Companies (Winding Up and Miscellaneous Provisions) Ordinance, the Takeovers Codes and the SFO. As a result, we have adopted different practices as to those matters as compared with other companies listed on the Hong Kong Stock Exchange that do not enjoy those exemptions or waivers.

Furthermore, if 55% or more of the total worldwide trading volume, by dollar value, of our ordinary shares and ADSs over our most recent fiscal year takes place on the Hong Kong Stock Exchange, the Hong Kong Stock Exchange will regard us as having a dual primary listing in Hong Kong and we will no longer enjoy certain exemptions or waivers from strict compliance with the requirements under the Listing Rules, the Companies (Winding Up and Miscellaneous Provisions) Ordinance, the Takeovers Codes and the SFO, which could result in our incurring of incremental compliance costs.

We have broad discretion to determine how to use the net proceeds from this offering and may use them in ways that may not enhance our results of operations or the price of the ADSs and/or ordinary shares.

Although we currently intend to use the net proceeds from this offering in the manner described in the section titled “Use of proceeds” in this prospectus supplement, our management will have broad discretion over the use of net proceeds from this offering, and we could spend the net proceeds from this offering in ways the holders of the ADSs and/or ordinary shares may not agree with or that do not yield a favorable return. Because of the number and variability of factors that will determine our use of the net proceeds from this offering, our use of these proceeds may differ substantially from our current plans. The failure by our management to apply these funds effectively could have a material adverse effect on our business, financial condition and results of operation. You will not have the opportunity, as part of your investment decision, to assess whether the net proceeds from this offering are being used appropriately. You must rely on the judgment of our management regarding the application of the net proceeds of this offering.

The market price and trading volume of our ADSs and/or our ordinary shares may be volatile, which could result in substantial loss to you.

The market price for our ADSs and/or ordinary shares has been volatile. From September 20, 2017 to April 16, 2021, the closing price of our ADSs on the Nasdaq Global Market ranged from a high of $193.54 to a low of $14.29 per ADS. From September 28, 2020 to April 16, 2021, the closing price of our ordinary shares on the Hong Kong Stock Exchange ranged from a high of HK$1,512.00 to a low of HK$602.00 per ordinary share.

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The trading price of the ADSs and ordinary shares is likely to be volatile and could fluctuate widely in response to a variety of factors, many of which are beyond our control. In addition, the performance and fluctuation of the market prices of other companies with business operations located mainly in China that have listed their securities in the United States may affect the volatility in the price of and trading volumes for our ADSs and ordinary shares. Some of these companies have experienced significant volatility, including significant price declines after their initial public offerings. The trading performances of these PRC companies’ securities at the time of or after their offerings may affect the overall investor sentiment towards other PRC companies listed in the United States and consequently may impact the trading performance of our ADSs and ordinary shares.

The market price and trading volume of our ADSs and ordinary shares are likely to continue to be highly volatile and subject to wide fluctuations in response to factors, including:

In addition, the securities markets have from time to time experienced significant price and volume fluctuations that are not related to the operating performance of particular companies. For example, since August 2008, multiple exchanges in the United States and other countries and regions, including China, experienced sharp declines in response to the growing credit market crisis and the recession in the United States. As recently as March 2020, the exchanges in the United States and China experienced a sharp decline. Prolonged global capital markets volatility may affect overall investor sentiment towards our ADSs and ordinary shares, which would also negatively affect the trading prices for our ADSs and ordinary shares.

We may be at an increased risk of securities class action litigation.

Historically, securities class action litigation has often been brought against a company following a decline in the market price of its securities. This risk is especially relevant for us because biotechnology and biopharmaceutical companies have experienced significant share price volatility in recent years. If we were to be sued, it could result in substantial costs and a diversion of management’s attention and resources, which could harm our business.

If securities or industry analysts do not continue to publish research or publish inaccurate or unfavorable research about our business, the market price for our ordinary shares and/or ADSs and trading volume could decline.

The trading markets for our ADSs and ordinary shares relies in part on the research and reports that equity research analysts publish about us or our business. We do not control these analysts. If research analysts do not maintain adequate research coverage or if one or more of the analysts who covers us downgrades our ordinary shares and/or ADSs or publishes inaccurate or unfavorable research about our business, the market price for our ADSs and/or ordinary shares would likely decline. If one or more of these analysts cease coverage of our company or fail to publish reports on us regularly, we could lose visibility in the financial markets, which, in turn, could cause the market price or trading volume for the ADSs and/or ordinary shares to decline significantly.

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If we fail to establish and maintain proper internal financial reporting controls, our ability to produce accurate financial statements or comply with applicable regulations could be impaired.

Pursuant to Section 404 of the Sarbanes-Oxley Act, we are required to file a report by our management on our internal control over financial reporting, including an attestation report on internal control over financial reporting issued by our independent registered public accounting firm. The presence of material weaknesses in internal control over financial reporting could result in financial statement errors which, in turn, could lead to errors in our financial reports and/or delays in our financial reporting, which could require us to restate our operating results. We might not identify one or more material weaknesses in our internal controls in connection with evaluating our compliance with Section 404 of the Sarbanes-Oxley Act. In order to maintain and improve the effectiveness of our disclosure controls and procedures and internal controls over financial reporting, we need to expend significant resources and provide significant management oversight. Implementing any appropriate changes to our internal controls may require specific compliance training of our directors and employees, entail substantial costs in order to modify our existing accounting systems, take a significant period of time to complete and divert management’s attention from other business concerns. These changes may not, however, be effective in maintaining the adequacy of our internal controls.

If we fail to maintain effective internal control over financial reporting in the future, our management and our independent registered public accounting firm may not be able to conclude that we have effective internal controls over financial reporting, investors may lose confidence in our operating results, the price of our ADSs and/or could decline and we may be subject to litigation or regulatory enforcement actions. In addition, if we are unable to meet the requirements of Section 404 of the Sarbanes-Oxley Act, the ADSs may not be able to remain listed on the Nasdaq Global Market.

The audit report included in our Form 10-K was prepared by an auditor who is not inspected by the U.S. Public Company Accounting Oversight Board, or the PCAOB, and as such, you are deprived of the benefits of such inspection.

Auditors of companies that are registered with the SEC and traded publicly in the United States, including the independent registered public accounting firm of our company, must be registered with the PCAOB, and are required by the laws of the United States to undergo regular inspections by the PCAOB to assess their compliance with the laws of the United States and professional standards. Because substantially all of our operations are within China, a jurisdiction where the PCAOB is currently unable to conduct inspections without the approval of the Chinese authorities, our auditor is not currently inspected by the PCAOB.

Inspections of auditors conducted by the PCAOB outside the PRC have at times identified deficiencies in those auditors’ audit procedures and quality control procedures, which may be addressed as part of the inspection process to improve future audit quality. The lack of PCAOB inspections of audit work undertaken in the PRC prevents the PCAOB from regularly evaluating our auditor’s audits and its quality control procedures. As a result, investors are deprived of the benefits of PCAOB inspections and may lose confidence in our reported financial information and procedures and the quality of our financial statements.

As part of a continued regulatory focus in the United States on access to audit and other information currently protected by national law, in particular China’s, in June 2019, a bipartisan group of lawmakers introduced bills in both houses of the U.S. Congress, which if passed, would require the SEC to maintain a list of issuers for which PCAOB is not able to inspect or investigate the audit work performed by a foreign public accounting firm completely. The proposed Ensuring Quality Information and Transparency for Abroad-Based Listings on our Exchanges Act prescribes increased disclosure requirements for these issuers and, beginning in 2025, the delisting from U.S. national securities exchanges such as the Nasdaq of issuers included on the SEC’s list for three consecutive years. It is unclear if this proposed legislation will be enacted.

Furthermore, there have been recent deliberations within the U.S. government regarding potentially limiting or restricting China-based companies from accessing U.S. capital markets. On May 20, 2020, the U.S. Senate

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passed the Holding Foreign Companies Accountable Act (HFCA Act), which includes requirements for the SEC to identify issuers whose audit work is performed by auditors that the PCAOB is unable to inspect or investigate completely because of a restriction imposed by a non-U.S. authority in the auditor’s local jurisdiction. The U.S. House of Representatives passed the HFCA Act on December 2, 2020, and the HFCA Act was signed into law on December 18, 2020. Additionally, in July 2020, the U.S. President’s Working Group on Financial Markets issued recommendations for actions that can be taken by the executive branch, the SEC, the PCAOB or other federal agencies and department with respect to Chinese companies listed on U.S. stock exchanges and their audit firms, in an effort to protect investors in the United States. In response, on November 23, 2020, the SEC issued guidance highlighting certain risks (and their implications to U.S. investors) associated with investments in China-based issuers and summarizing enhanced disclosures the SEC recommends China-based issuers make regarding such risks. On March 24, 2021, the SEC adopted interim final rules relating to the implementation of certain disclosure and documentation requirements of the HFCA Act. We will be required to comply with these rules if the SEC identifies us as having a “non-inspection” year (as defined in the interim final rules) under a process to be subsequently established by the SEC. The SEC is assessing how to implement other requirements of the HFCA Act, including the listing and trading prohibition requirements described above. Under the HFCA Act, our securities may be prohibited from trading on the Nasdaq or other U.S. stock exchanges if our auditor is not inspected by the PCAOB for three consecutive years, and this ultimately could result in our ADSs being delisted. While we understand that there has been dialogue among the China Securities Regulatory Commission (CSRC), the SEC and the PCAOB regarding the inspection of PCAOB-registered accounting firms in China, there can be no assurance that we or our auditor will be able to comply with requirements imposed by U.S. regulators. Delisting of our ADSs would force holders of our ADSs to sell their ADSs or convert them into our ordinary shares. The market price of our ADSs and ordinary shares could be adversely affected as a result of anticipated negative impacts of these executive or legislative actions upon, as well as negative investor sentiment towards, companies with significant operations in China that are listed in the United States, regardless of whether these executive or legislative actions are implemented and regardless of our actual operating performance.

We do not currently intend to pay dividends on our securities, and, consequently, your ability to achieve a return on your investment will depend on appreciation in the price of our ordinary shares and/or ADSs.

We have never declared or paid any dividends on our ordinary shares. We currently intend to invest our future earnings, if any, to fund our growth. Therefore, investors are not likely to receive any dividends on their ordinary shares and/or ADSs at least in the near term, and the success of an investment in our ordinary shares and/or ADSs will depend upon any future appreciation in its value. Consequently, investors may need to sell all or part of their holdings of our ordinary shares and/or ADSs after price appreciation, which may never occur, to realize any future gains on their investment. There is no guarantee that our ordinary shares and/or ADSs will appreciate in value or even maintain the price at which our investors purchased the ordinary shares and/or ADSs.

Fluctuations in the value of the renminbi, or RMB, may have a material adverse effect on our results of operations and the value of your investment.

The value of the renminbi against the U.S. dollar and other currencies may fluctuate and is affected by, among other things, changes in political and economic conditions. On July 21, 2005, the PRC government changed its decade-old policy of pegging the value of the renminbi to the U.S. dollar, and the renminbi appreciated more than 20% against the U.S. dollar over the following three years. Between July 2008 and June 2010, this appreciation halted, and the exchange rate between the renminbi and U.S. dollar remained within a narrow band. In June 2010, China’s People’s Bank of China, or PBOC, announced that the PRC government would increase the flexibility of the exchange rate, and thereafter allowed the renminbi to appreciate slowly against the U.S. dollar within the narrow band fixed by the PBOC. However, more recently, on August 11, 12 and 13, 2015, the PBOC significantly devalued the renminbi by fixing its price against the U.S. dollar 1.9%, 1.6%, and 1.1% lower than the previous day’s value, respectively. On October 1, 2016, the renminbi joined the International Monetary Fund’s basket of currencies that make up the Special Drawing Right, or SDR, along with the U.S. dollar, the Euro, the Japanese yen and the British pound. In the fourth quarter of 2016, the renminbi depreciated

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significantly while the U.S. dollar surged and China experienced persistent capital outflows. With the development of the foreign exchange market and progress towards interest rate liberalization and renminbi internationalization, the PRC government may in the future announce further changes to the exchange rate system. There is no guarantee that the renminbi will not appreciate or depreciate significantly in value against the U.S. dollar in the future. It is difficult to predict how market forces or PRC or U.S. government policy may impact the exchange rate between the renminbi and the U.S. dollar in the future.

Significant revaluation of the renminbi may have a material adverse effect on your investment. For example, to the extent that we need to convert U.S. dollars into renminbi for our operations, appreciation of the renminbi against the U.S. dollar would have an adverse effect on the renminbi amount we would receive from the conversion. Conversely, if we decide to convert our renminbi into U.S. dollars for the purpose of making payments for dividends on our ordinary shares or ADSs or for other business purposes, appreciation of the U.S. dollar against the renminbi would have a negative effect on the U.S. dollar amount available to us. In addition, appreciation or depreciation in the value of the renminbi relative to U.S. dollars would affect our financial results reported in U.S. dollar terms regardless of any underlying change in our business or results of operations.

Very limited hedging options are available in China to reduce our exposure to exchange rate fluctuations. To date, we have not entered into any hedging transactions in an effort to reduce our exposure to foreign currency exchange risk. While we may decide to enter into hedging transactions in the future, the availability and effectiveness of these hedges may be limited and we may not be able to adequately hedge our exposure or at all. In addition, our currency exchange losses may be magnified by PRC exchange control regulations that restrict our ability to convert renminbi into foreign currency.

Substantial future sales or perceived potential sales of our ordinary shares, ADSs, or other equity or equity-linked securities in the public market could cause the price of our ordinary shares and/or ADSs to decline.

Sales of our ordinary shares, ADSs, or other equity or equity-linked securities in the public market, or the perception that these sales could occur, could cause the market price of our ordinary shares and/or ADSs to decline significantly. All of our ordinary shares represented by ADSs were freely transferable by persons other than our affiliates without restriction or additional registration under the U.S. Securities Act. The ordinary shares held by our affiliates are also available for sale, subject to volume and other restrictions as applicable under Rule 144 of the U.S. Securities Act, under trading plans adopted pursuant to Rule 10b5-1 or otherwise.

Divestiture in the future of our ordinary shares and/or ADSs by shareholders, the announcement of any plan to divest our ordinary shares and/or ADS, or hedging activity by third-party financial institutions in connection with similar derivative or other financing arrangements entered into by shareholders, could cause the price of our ordinary shares and/or ADSs to decline.

Furthermore, although all of our directors and executive officers have agreed to a lock-up of their ordinary shares, any major disposal of our ordinary shares and/or ADSs by any of them upon expiration of the relevant lock-up periods (or the perception that these disposals may occur upon the expiration of the lock-up period) may cause the prevailing market price of our ordinary shares and/or ADSs to fall which could negatively impact our ability to raise equity capital in the future.

Holders of ADSs have fewer rights than holders of ordinary shares and must act through the depositary to exercise their rights.

Holders of our ADSs do not have the same rights as our shareholders and may only exercise the voting rights with respect to the underlying ordinary shares in accordance with the provisions of the deposit agreement. Under our fifth amended and restated articles of association, an annual general meeting and any extraordinary general meeting may be called with not less than seven days’ notice. When a general meeting is convened, you may not

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receive sufficient notice of a shareholders’ meeting to permit you to withdraw the ordinary shares underlying your ADSs to allow you to vote with respect to any specific matter. If we ask for your instructions, we will give the depositary notice of any such meeting and details concerning the matters to be voted upon at least 30 days in advance of the meeting date and the depositary will send a notice to you about the upcoming vote and will arrange to deliver our voting materials to you. The depositary and its agents, however, may not be able to send voting instructions to you or carry out your voting instructions in a timely manner. We will make all commercially reasonable efforts to cause the depositary to extend voting rights to you in a timely manner, but we cannot assure you that you will receive the voting materials in time to ensure that you can instruct the depositary to vote the ordinary shares underlying your ADSs. Furthermore, the depositary will not be liable for any failure to carry out any instructions to vote, for the manner in which any vote is cast or for the effect of any such vote. As a holder or beneficial owner of ADSs, you may have limited recourse if we or the depositary fail to meet our respective obligations under the deposit agreement or if you wish us or the depositary to participate in legal proceedings. As a result, you may not be able to exercise your right to vote and you may lack recourse if your ADSs are not voted as you request. In addition, in your capacity as an ADS holder, you will not be able to call a shareholders’ meeting.

Under the deposit agreement for the ADSs, the depositary will give us a discretionary proxy to vote the ordinary shares underlying your ADS at a shareholders’ meeting if you do not give instructions to the depositary, unless (i) we have failed to timely provide the depositary with our notice of meeting and related voting materials, (ii) we have instructed the depositary that we do not wish a discretionary proxy to be given, (iii) we have informed the depositary that there is a substantial opposition as to a matter to be voted on at the meeting or (iv) a matter to be voted on at the meeting would have a material adverse impact on shareholders.

The effect of this discretionary proxy is that, if you fail to give voting instructions to the depositary, you cannot prevent the ordinary shares underlying your ADSs from being voted, except under the circumstances described above. This may adversely affect your interests and make it more difficult for ADS holders to influence the management of our company. Holders of our ordinary shares are not subject to this discretionary proxy.

You may not receive distributions on our ADSs or any value for them if such distribution is illegal or impractical or if any required government approval cannot be obtained in order to make such distribution available to you.

Although we do not have any present plan to pay any dividends, the depositary of our ADSs has agreed to pay to you the cash dividends or other distributions it or the custodian receives on ordinary shares or other deposited securities underlying our ADSs, after deducting its fees and expenses and any applicable taxes and governmental charges. You will receive these distributions in proportion to the number of ordinary shares your ADSs represent. However, the depositary is not responsible if it decides that it is unlawful or impractical to make a distribution available to any holders of ADSs. For example, it would be unlawful to make a distribution to a holder of ADSs if it consists of securities whose offering would require registration under the Securities Act but are not so properly registered or distributed under an applicable exemption from registration. The depositary may also determine that it is not reasonably practicable to distribute certain property. In these cases, the depositary may determine not to distribute such property. We have no obligation to register under the U.S. securities laws any offering of ADSs, ordinary shares, rights or other securities received through such distributions. We also have no obligation to take any other action to permit the distribution of ADSs, ordinary shares, rights or anything else to holders of ADSs. This means that you may not receive distributions we make on our ordinary shares or any value for them if it is illegal or impractical for us to make them available to you. These restrictions may cause a material decline in the value of our ADSs.

Your right to participate in any future rights offerings may be limited, which may cause dilution to your holdings.

We may from time to time distribute rights to our shareholders, including rights to acquire our securities. However, we cannot make rights available to investors in the United States unless we register the rights and the securities to which the rights relate under the Securities Act or an exemption from the registration requirements is available. Also, under the deposit agreement, the depositary bank will not make rights available to you unless

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either both the rights and any related securities are registered under the Securities Act, or the distribution of them to ADS holders is exempted from registration under the Securities Act. We are under no obligation to file a registration statement with respect to any such rights or securities or to endeavor to cause such a registration statement to be declared effective. Moreover, we may not be able to establish an exemption from registration under the Securities Act. If the depositary does not distribute the rights, it may, under the deposit agreement, either sell them, if possible, or allow them to lapse. Accordingly, you may be unable to participate in our rights offerings and may experience dilution in your holdings.

Taxing authorities could reallocate our taxable income among our subsidiaries, which could increase our overall tax liability.

We are incorporated under the laws of the Cayman Islands and currently have subsidiaries in China, Hong Kong, the Cayman Islands, the United States, Australia and the British Virgin Islands. If we succeed in growing our business we expect to conduct increased operations through our subsidiaries in various tax jurisdictions pursuant to transfer pricing arrangements between us, our parent company and our subsidiaries. If two or more affiliated companies are located in different countries, the tax laws or regulations of each country generally will require that transfer prices be the same as those between unrelated companies dealing at arms’ length and that appropriate documentation is maintained to support the transfer prices. While we believe that we operate in compliance with applicable transfer pricing laws and intend to continue to do so, our transfer pricing procedures are not binding on applicable tax authorities.

If tax authorities in any of these countries were to successfully challenge our transfer prices as not reflecting arms’ length transactions they could require us to adjust our transfer prices and thereby reallocate our income to reflect these revised transfer prices, which could result in a higher tax liability to us. In addition, if the country from which the income is reallocated does not agree with the reallocation, both countries could tax the same income, resulting in double taxation. If tax authorities were to allocate income to a higher tax jurisdiction, subject our income to double taxation or assess interest and penalties, it would increase our consolidated tax liability, which could adversely affect our financial condition, results of operations and cash flows.

A tax authority could assert that we are subject to tax in a jurisdiction where we believe we have not established a taxable connection, often referred to as a “permanent establishment” under international tax treaties, and such an assertion, if successful, could increase our expected tax liability in one or more jurisdictions. A tax authority may take the position that material income tax liabilities, interest and penalties are payable by us, in which case, we expect that we might contest such assessment. Contesting such an assessment may be lengthy and costly and if we were unsuccessful in disputing the assessment, the implications could increase our anticipated effective tax rate, where applicable.

Zai Lab Limited is a holding company with no operations of its own and, as such, it depends on its subsidiaries for cash to fund all of its operations and expenses, including future dividend payments, if any.

Our operations are conducted almost entirely through our subsidiaries and our ability to generate cash to make future dividend payments, if any, will be highly dependent on the earnings and the receipt of funds from our subsidiaries via dividends or intercompany loans. There can be no assurance that our subsidiaries will generate sufficient cash flow to distribute funds to us or that applicable law and contractual restrictions, if any, will permit such distributions.

There can be no assurance that we will not be a passive foreign investment company (“PFIC”) for U.S. federal income tax purposes for any taxable year, which could subject U.S. investors in our ADSs or ordinary shares to significant adverse U.S. federal income tax consequences.

In general, a non-U.S. corporation will be a PFIC for any taxable year in which (i) 75% or more of its gross income consists of passive income or (ii) 50% or more of the value of its assets (generally determined on a quarterly average basis) consists of assets that produce, or are held for the production of, passive income (the “asset test”). For purposes of the above calculations, a non-U.S. corporation that directly or indirectly owns at least 25% by value of the shares of another corporation is treated as if it held its proportionate share of the assets of the other corporation and received directly its proportionate share of the income of the other corporation.

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Passive income generally includes interest, dividends and gains from certain property transactions, rents and royalties (other than certain rents or royalties derived in the active conduct of a trade or business). For these purposes, cash is a passive asset and the value of a non-U.S. corporation’s goodwill (which may be determined by reference to the excess of the sum of its market capitalization and liabilities over its booked assets) generally should be an active asset to the extent attributable to business activities that produce non-passive income.

Our assets other than goodwill are expected to consist primarily of cash and cash equivalents for the foreseeable future. Therefore, whether we will satisfy the asset test for the current or any future taxable year will depend largely on the quarterly value of our goodwill (which may be determined by reference to the market price of our ADSs or ordinary shares, which has been, and may continue to be volatile given the nature and early stage of our business). If our market capitalization declines while we continue to hold a significant amount of cash (including cash raised in this offering) the risk that we will be a PFIC will increase. Furthermore, we may be a PFIC for any taxable year in which our interest and other investment income constitutes 75% or more of the sum of (i) such interest and investment income and (ii) the excess of our revenue over cost of goods sold. In addition, a company’s PFIC status is an annual determination that can be made only after the end of each taxable year. Based on our current market capitalization and our current and expected composition of income and assets, we do not expect to be a PFIC for our current taxable year, although we cannot give any assurance as to whether we are a PFIC for the current or any future taxable year.

Subject to the discussion in the next paragraph, if we are or become a PFIC, U.S. investors generally would be subject to adverse U.S. federal income tax consequences, such as increased tax liabilities on capital gains and certain distributions, and interest charges on taxes deemed to be deferred. If we are a PFIC for any taxable year during which a U.S. investor owns ADSs or ordinary shares, we will generally continue to be treated as a PFIC with respect to such investor for all succeeding years during which the investor own ADSs or ordinary shares (unless the investor timely makes a valid “deemed sale” election), even if we cease to meet the threshold requirements for PFIC status. A mark-to-market election may be available with respect our ADSs, which would result in U.S. federal income tax consequences to holders of our ADSs that are different from those described above.

U.S. investors would be subject to alternative treatment if we are a PFIC for any taxable year and we provide the information necessary to make a qualified electing fund (“QEF”) election. If we determine at our discretion that we were a PFIC for any taxable year, we intend to provide to U.S investors, following their request, the information necessary for them to make a QEF election with respect to us. U.S. investors that make the QEF election for the first taxable year that we are a PFIC will be taxed on a current basis on their pro rata share of our ordinary earnings and net capital gain (at ordinary income and capital gain rates, respectively) for each taxable year that we are a PFIC. Any distributions paid by us out of our earnings and profits that were previously included in the U.S. investor’s income under the QEF election would not be taxable to such investors. U.S. investors will increase their tax basis in their ADSs or ordinary shares by an amount equal to any income included under the QEF election and will decrease their tax basis by any amount distributed on the ADSs or ordinary shares that is not included in income. U.S. investors that make QEF elections may be required to pay U.S. federal income tax with respect to their ADSs or ordinary shares for any taxable year significantly in excess of any cash distributions received on the ADSs or ordinary shares for such taxable year. U.S. investors should consult their tax advisors regarding the consequences of making a valid and timely QEF election if we are a PFIC.

If a U.S. investor owns ADSs or ordinary shares during any year in which we are a PFIC, such investor generally will be required to file annual reports on IRS Form 8621 (or any successor form) with respect to us, generally with their U.S. federal income tax return for that year. U.S. investors should consult their tax advisors regarding the determination of whether we are a PFIC for any taxable year and the potential application of the PFIC rules.

You may have difficulty enforcing judgments obtained against us.

We are a company incorporated under the laws of the Cayman Islands, and substantially all of our assets are located outside the United States. Substantially all of our current operations are conducted in the PRC. In

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addition, some of our directors and officers are nationals and residents of countries or regions other than the United States or Hong Kong. A substantial portion of the assets of these persons are located outside the United States. As a result, it may be difficult for investors to effect service of process within the United States or Hong Kong upon these persons, or to bring an action against us or against these individuals in the United States or Hong Kong in the event that they believe that their rights have been infringed under the U.S. federal securities laws, Hong Kong laws or otherwise. Even if shareholders are successful in bringing an action of this kind, the laws of the Cayman Islands and the PRC may render them unable to enforce a judgment against our assets or the assets of our directors and officers. There is uncertainty as to whether the courts of the Cayman Islands or the PRC would recognize or enforce judgments of U.S. courts against us or such persons predicated upon the civil liability provisions of the securities laws of the United States or any state.

The recognition and enforcement of foreign judgments are provided for under the PRC Civil Procedures Law. PRC courts may recognize and enforce foreign judgments in accordance with the requirements of the PRC Civil Procedures Law based either on treaties between the PRC and the country where the judgment is made or on principles of reciprocity between jurisdictions. The PRC does not have any treaties or other forms of reciprocity with the United States that provide for the reciprocal recognition and enforcement of foreign judgments. In addition, according to the PRC Civil Procedures Law, the PRC courts will not enforce a foreign judgment against us or our directors and officers if they decide that the judgment violates the basic principles of Chinese laws or national sovereignty, security or public interest. As a result, it is uncertain whether and on what basis a Chinese court would enforce a judgment rendered by a court in the United States.

As there is no statutory or other arrangement for the reciprocal enforcement of judgments between Hong Kong and the United States, a judgement obtained in a court in the United States cannot be enforced by registration in Hong Kong. Subject to the Foreign Judgments (Restriction on Recognition and Enforcement) Ordinance (Cap. 46 of the Laws of Hong Kong), a Hong Kong court may refuse to recognize or enforce a United States court judgment if recognition of the judgment is restricted by operation of the provisions of the Foreign Judgements Ordinance, obtained by fraud, rendered by a foreign court that lacked the appropriate jurisdiction, contrary to Hong Kong public policy, is for penal damages, is based on foreign penal, review or other public law, or is inconsistent with a prior Hong Kong judgement or foreign judgment which is entitled to recognition in Hong Kong. As a result, it is uncertain whether a Hong Kong court would recognize or enforce a judgment rendered by a court in the United States.

Investors may be subject to limitations on transfers of your ADSs.

ADSs are transferable on the books of the depositary. However, the depositary may close its transfer books at any time or from time to time when it deems expedient in connection with the performance of its duties. In addition, the depositary may refuse to deliver, transfer or register transfers of ADSs generally when our books or the books of the depositary are closed, or at any time if we or the depositary deems it advisable to do so because of any requirement of law or of any government or governmental body, or under any provision of the deposit agreement, or for any other reason.

As the public offering price is higher than our net tangible book value per ordinary share and per ADSs, you will incur immediate and substantial dilution.

If you purchase ADSs or ordinary shares in this offering, you will pay more for your ADSs or ordinary shares than the amount paid by existing shareholders for their ordinary shares on a per ADS basis. As a result, you will experience immediate and substantial dilution of $129.71 per ADS and $129.71 per ordinary share (assuming no exercise of outstanding options to acquire ordinary shares and no exercise of the underwriters’ option to purchase additional ADSs), representing the difference between our as adjusted net tangible book value per ordinary share as of December 31, 2020, after giving effect to this offering, and the public offering price of $150.00 per ADS (which is also the equivalent thereof per ordinary share). In addition, you will experience further dilution to the extent that our ordinary shares are issued upon the exercise of share options. All of the ordinary shares issuable upon the exercise of currently outstanding share options will be issued at a purchase price on a per ADS basis that is less than the public offering price per ADS in this offering.

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We are a Cayman Islands company. Because judicial precedent regarding the rights of shareholders is more limited under Cayman Islands law than under Hong Kong law or U.S. law, shareholders may have fewer shareholder rights than they would have under Hong Kong law or U.S. law and may face difficulties in protecting your interests.

We are an exempted company with limited liability incorporated in the Cayman Islands. Our corporate affairs are governed by our Articles of Association (as may be further amended from time to time), the Companies Law (as amended) of the Cayman Islands and the common law of the Cayman Islands. The rights of shareholders to take action against the directors, actions by minority shareholders and the fiduciary responsibilities of our directors are to a large extent governed by the common law of the Cayman Islands. This common law is derived in part from comparatively limited judicial precedent in the Cayman Islands as well as from English common law, which has persuasive, but not binding, authority on a court in the Cayman Islands. The rights of our shareholders and the fiduciary responsibilities of our directors under Cayman Islands law are not as clearly established as they would be under statutes or judicial precedent in some jurisdictions in Hong Kong and the United States. In particular, the Cayman Islands has a less developed body of securities law than the Hong Kong or United States. In addition, some states in the United States, such as Delaware, have more fully developed and judicially interpreted bodies of corporate law than the Cayman Islands.

In addition, as a Cayman Islands exempted company, our shareholders have no general rights under Cayman Islands law to inspect corporate records and accounts or to obtain copies of lists of shareholders of these companies with the exception that the shareholders may request a copy of the Articles of Association. Our directors have discretion under our articles of association to determine whether or not, and under what conditions, our corporate records may be inspected by our shareholders, but are not obliged to make them available to our shareholders. This may make it more difficult for you to obtain the information needed to establish any facts necessary for a shareholder motion or to solicit proxies from other shareholders in connection with a proxy contest. As a Cayman Islands company, we may not have standing to initiate a derivative action in a federal court of the United States. As a result, you may be limited in your ability to protect your interests if you are harmed in a manner that would otherwise enable you to sue in a Hong Kong or U.S. federal court. In addition, shareholders of Cayman Islands companies may not have standing to initiate a shareholder derivative action in Hong Kong or United States federal courts.

Some of our directors and executive officers reside outside of Hong Kong and the United States and a substantial portion of their assets are located outside of Hong Kong and the United States. As a result, it may be difficult or impossible for you to bring an action against us or against these individuals in the Cayman Islands or in China in the event that you believe that your rights have been infringed under the securities laws of Hong Kong, the United States or otherwise. In addition, some of our operating subsidiaries are incorporated in China. To the extent our directors and executive officers reside in China or their assets are located in China, it may not be possible for investors to effect service of process upon us or our management inside China. Even if you are successful in bringing an action, the laws of the Cayman Islands and China may render you unable to enforce a judgment against our assets or the assets of our directors and officers. There is no statutory recognition in the Cayman Islands of judgments obtained in the United States, Hong Kong or China, although the courts of the Cayman Islands will generally recognize and enforce a non-penal judgment of a foreign court of competent jurisdiction without retrial on the merits.

As a result of all of the above, public shareholders may have more difficulty in protecting their interests in the face of actions taken by management, members of the Board or controlling shareholders than they would as public shareholders of a Hong Kong company or a U.S. company.

The different characteristics of the capital markets in Hong Kong and the U.S. may negatively affect the trading prices of our ordinary shares and/or ADSs.

We are subject to Hong Kong and Nasdaq listing and regulatory requirements concurrently. Hong Kong Stock Exchange and Nasdaq have different trading hours, trading characteristics (including trading volume and

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liquidity), trading and listing rules, and investor bases (including different levels of retail and institutional participation). As a result of these differences, the trading prices of our ordinary shares on the . Hong Kong Stock Exchange and our ADSs on Nasdaq may not be the same, even allowing for currency differences. Fluctuations in the price of our ordinary shares due to circumstances peculiar to the Hong Kong capital markets could materially and adversely affect the price of our ordinary shares and/or ADSs, or vice versa. Certain events having significant negative impact specifically on the Hong Kong capital markets may result in a decline in the trading price of our ADSs notwithstanding that such event may not impact the trading prices of securities listed in Hong Kong generally or to the same extent, or vice versa.

Exchange between our ordinary shares and our ADSs may adversely affect the liquidity and/or trading price of each other.

Subject to compliance with U.S. securities law and the terms of the deposit agreement, holders of our ordinary shares may deposit such ordinary shares with the depositary in exchange for the issuance of our ADSs. Any holder of ADSs may also withdraw the underlying ordinary shares represented by the ADSs pursuant to the terms of the deposit agreement for trading on the Hong Kong Stock Exchange. In the event that a substantial number of our ordinary shares are deposited with the depositary in exchange for ADSs or vice versa, the liquidity and trading price of our ordinary shares on the Hong Kong Stock Exchange and our ADSs on Nasdaq may be adversely affected.

The time required for the exchange between our ordinary shares and ADSs might be longer than expected and investors might not be able to settle or effect any sale of their securities during this period, and the exchange of ordinary shares into ADSs involves costs.

There is no direct trading or settlement between Nasdaq and the Hong Kong Stock Exchange on which our ADSs and our ordinary shares are respectively traded. In addition, the time differences between Hong Kong and New York and unforeseen market circumstances or other factors may delay the deposit of ordinary shares in exchange of ADSs or the withdrawal of ordinary shares underlying the ADSs. Investors will be prevented from settling or effecting the sale of their securities during such periods of delay. In addition, there is no assurance that any exchange of ordinary shares into ADSs (and vice versa) will be completed in accordance with the timelines investors may anticipate.

Furthermore, the depositary for the ADSs is entitled to charge holders fees for various services including for the issuance of ADSs upon deposit of ordinary shares, cancelation of ADSs, distributions of cash dividends or other cash distributions, distributions of ADSs pursuant to share dividends or other free share distributions, distributions of securities other than ADSs and annual service fees. As a result, shareholders who exchange ordinary shares into ADSs, and vice versa, may not achieve the level of economic return the shareholders may anticipate.

The settlement of each of the ADSs and the ordinary shares offered hereby are not conditioned upon the settlement of each other.

The ADSs offered hereby will settle on or about April 23, 2021 on a “T+2” basis and the ordinary shares will settle on or about April 28, 2021 on a “T+5” basis. The closing of the ADSs offered hereby is not conditioned on the closing of the ordinary shares offered hereby and the closing of the ordinary shares is not conditioned on the closing of the ADSs. There is no guarantee that the ADSs and/or the ordinary shares will close within the expected time frame or at all. There is a risk that either the ADSs or the ordinary shares will not close while the other closes. In the event that one or both of the ADSs and ordinary shares do not settle, the liquidity and trading price of our ordinary shares on the Hong Kong Stock Exchange and our ADSs on Nasdaq may be adversely affected.

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You should read the entire document carefully, and we strongly caution you not to place any reliance on any information contained in press articles or other media regarding us.

Subsequent to the date of this prospectus but prior to the completion of this offering, there may be press and media coverage regarding us and this offering, which may contain, among other things, certain financial information, projections, valuations and other forward-looking information about us and this offering. We have not authorized the disclosure of any such information in the press or media and do not accept responsibility for the accuracy or completeness of such press articles or other media coverage. We make no representation as to the appropriateness, accuracy, completeness or reliability of any of the projections, valuations or other forward-looking information about us. We expressly disclaim responsibility for any such information. Accordingly, prospective investors are cautioned to make their investment decisions on the basis of the information contained or incorporated by reference in this prospectus supplement and the accompanying prospectus only and should not rely on any other information.

An active trading market for our ordinary shares on the Hong Kong Stock Exchange might not be sustained and trading prices of our ordinary shares might fluctuate significantly.

We cannot assure you that an active trading market for our ordinary shares on the Hong Kong Stock Exchange will be sustained. The trading price or liquidity for our ADSs on Nasdaq might not be indicative of those of our ordinary shares on the Hong Kong Stock Exchange. If an active trading market of our ordinary shares on the Hong Kong Stock Exchange does not develop or is not sustained, the market price and liquidity of our ordinary shares could be materially and adversely affected.

The Hong Kong Stock Exchange collaborated with Shanghai Stock Exchanges and Shenzhen Stock Exchanges in 2014 and 2016 respectively to create an inter-exchange trading mechanism called Stock Connect that allows international and mainland Chinese investors to trade eligible equity securities listed in each other’s markets through the trading and clearing facilities of their home exchange. Stock Connect currently covers over 2,000 equity securities trading in the Hong Kong, Shanghai and Shenzhen markets. Stock Connect allows mainland Chinese investors to trade directly in eligible equity securities listed on the Hong Kong Stock Exchange, known as Southbound Trading; without Stock Connect, mainland Chinese investors would not otherwise have a direct and established means of engaging in Southbound Trading. The ineligibility or any delay of our ordinary shares for trading through Stock Connect will affect mainland Chinese investors’ ability to trade our ordinary shares and therefore may limit the liquidity of the trading of our ordinary shares on the Hong Kong Stock Exchange.

There is uncertainty as to whether Hong Kong stamp duty will apply to the trading or conversion of our ADS now that our ordinary shares are listed on the Hong Kong Stock Exchange.

In connection with our Hong Kong listing, we have established a branch register of members in Hong Kong, or the Hong Kong share register. Our ordinary shares that are traded on the Hong Kong Stock Exchange, including those to be issued in this offering and those that be converted from ADSs, will be registered on the Hong Kong share register, and the trading of these ordinary shares on the Stock Exchange of Hong Kong will be subject to the Hong Kong stamp duty. To facilitate ADS ordinary share conversion and trading between Nasdaq and Hong Kong Stock Exchange, we have moved a portion of our issued ordinary shares from our register of members maintained in the Cayman Islands to our Hong Kong share register.

Under the Hong Kong Stamp Duty Ordinance, any person who effects any sale or purchase of Hong Kong stock, defined as stock the transfer of which is required to be registered in Hong Kong, is required to pay Hong Kong stamp duty. The stamp duty is currently set at a total rate of 0.2% of the greater of the consideration for, or the value of, shares transferred, with 0.1% payable by each of the buyer and the seller. To the best of our knowledge, Hong Kong stamp duty has not been levied in practice on the trading or conversion of ADSs of companies that are listed in both the United States and Hong Kong and that have maintained all or a portion of their ordinary shares, including ordinary shares underlying ADSs, in their Hong Kong share registers. However, it is unclear

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whether, as a matter of Hong Kong law, the trading or conversion of ADSs of these dual-listed companies constitutes a sale or purchase of the underlying Hong Kong-registered ordinary shares that is subject to Hong Kong stamp duty. We advise investors to consult their own tax advisors on this matter. If Hong Kong stamp duty is determined by the competent authority to apply to the trading or conversion of our ADSs, the trading price and the value of your investment in our ADSs and/or ordinary shares may be affected.

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Use of proceeds

We estimate that the net proceeds to us from the sale of 4,776,000 ADSs and 224,000 ordinary shares offered by us in this offering will be approximately $715.43 million, and after deducting estimated underwriting discounts and commissions and estimated offering expenses payable by us. If the underwriters’ option to purchase 716,400 additional ADSs is exercised in full, we estimate that our net proceeds from this offering will be approximately $818.05 million, after deducting estimated underwriting discounts and commissions and estimated offering expenses payable by us.

We intend to use the net proceeds of this offering primarily for increased business and corporate development activity, to advance the clinical development of multiple drug candidates, to expand our commercialization efforts, and for working capital and other general corporate purposes. In particular, we currently expect to use the net proceeds from this offering as follows:

The expected use of net proceeds from this offering represents our intentions based upon our current plans and business conditions, which we could change in our discretion in the future as our plans and business conditions evolve. Due to the many variables inherent to the development of our drug candidates at this time, such as the timing of patient enrollment and evolving regulatory requirements, we cannot currently predict the stage of development we expect to achieve for our pre-clinical and clinical trial and drug candidates with the net proceeds of this offering. The amounts and timing of our actual expenditures may vary significantly depending on numerous factors, including the results of the pre-clinical and clinical trials of our drug candidates, our operating costs and expenditures and the amount of cash generated by our operations. As a result, our management will have broad discretion over the use of the net proceeds from this offering.

Pending these uses, we intend to invest the net proceeds in investment-grade, short-term fixed income instruments.

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Capitalization

The following table sets forth our capitalization as of December 31, 2020:

You should read the following table together with our consolidated financial statements and the related notes included in our Form 10-K, which is incorporated herein by reference and the information set forth therein under “Operating and Financial Review and Prospects” incorporated by reference in this prospectus supplement.

The actual and as adjusted information set forth in the table excludes:

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Dividend policy

We have never declared or paid dividends on our ordinary shares. We currently expect to retain all future earnings for use in the operation and expansion of our business and do not have any present plan to pay any dividends. The declaration and payment of any dividends in the future will be determined by our board of directors in its discretion, and will depend on a number of factors, including our earnings, capital requirements, overall financial condition, and contractual restrictions.

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Dilution

If you invest in our ADSs or ordinary shares, your investment will be diluted for each ADS or ordinary share you purchase to the extent of the difference between the public offering price per ADS or ordinary share, as applicable, and our net tangible book value per ordinary share immediately after this offering. Dilution results from the fact that the public offering price per ADS or ordinary share, as applicable, is in excess of the book value per ordinary share, attributable to the existing shareholders for our presently outstanding ADSs or ordinary shares.

As of December 31, 2020, we had a net tangible book value of $1,167.8 million, or $13.30 per ordinary share. We calculate net tangible book value per ordinary shares by dividing our total tangible assets less our total liabilities by the number of our ordinary shares outstanding. Dilution is determined by subtracting the as adjusted net tangible book value per ordinary share from the public offering price per ordinary share. Without taking into account any other changes in such net tangible book value after December 31, 2020, after giving effect to the receipt of the estimated net proceeds from our sale of 4,776,000 ADSs and 224,000 ordinary shares in this offering, and the application of the estimated net proceeds therefrom as described under “Use of proceeds,” our as adjusted net tangible book value at December 31, 2020 (at the public offering price of $150.00 per ADS and HK$1,164.20 per ordinary share) would have been approximately $1,883.2 million, or $20.29 per ordinary share and $20.29 per ADS. This represents an immediate increase in net tangible book value of $6.99 per ordinary share and $6.99 per ADS to existing shareholders and an immediate dilution in net tangible book value of $129.71 per ordinary share and $129.71 per ADS to you. The following table illustrates this dilution on a per ordinary share and per ADS basis.

If the underwriters exercise their option to purchase 716,400 additional ADSs in full (which assumes no investors elect to settle in ordinary shares and represents a total price to public of $107.5 million), the as adjusted net tangible book value would be $21.23 per ordinary shares and $21.23 per ADS, and the dilution in as adjusted net tangible book value to investors in this offering would be $128.77 per ordinary shares and $128.77 per ADS.

The following table sets forth, as of December 31, 2020, the number of ordinary shares purchased from us, the total consideration paid to us and the average price per ordinary share/ADS paid by existing shareholders and to be paid by new investors purchasing ADSs in this offering, before deducting underwriting discounts and commissions and estimated offering expenses payable by us.

If the underwriters were to fully exercise their option to purchase 716,400 additional ADSs from us (which assumes no investors elect to settle in ordinary shares and represents a total price to public of $107.5 million), the percentage of our ordinary shares held by existing shareholders and ADS holders would be 93.90%, and the percentage of our ordinary shares and ADSs held by new investors would be 6.10%.

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The above discussion and tables are based on 88,024,161 ordinary shares issued and outstanding as of December 31, 2020 and excludes:

To the extent that outstanding options and warrants are exercised, you will experience further dilution. In addition, we may choose to raise additional capital due to market conditions or strategic considerations even if we believe we have sufficient funds for our current or future operating plans. To the extent that additional capital is raised through the sale of equity or convertible debt securities, the issuance of these securities may result in further dilution to our shareholders.

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Underwriting

We are offering the ADSs described in this prospectus supplement through a number of underwriters. J.P. Morgan Securities LLC, Goldman Sachs & Co. LLC, Jefferies LLC, Citigroup Global Markets Inc. and SVB Leerink LLC are acting as joint book-running managers of the offering of ADSs and as representatives of the underwriters. and J.P. Morgan Securities plc, Goldman Sachs (Asia) L.L.C., Jefferies Hong Kong Limited, Citigroup Global Markets Limited and Guggenheim Securities, LLC are acting as joint book-running managers in respect of any ordinary shares issued to investor electing to receive ordinary shares in lieu of ADSs. We have entered into underwriting agreements with the underwriters in respect of the ADSs and ordinary shares to be sold in this offering. Subject to the terms and conditions of the underwriting agreements, we have agreed to sell to the underwriters, and each underwriter has severally agreed to purchase, at the public offering price less the underwriting discounts and commissions set forth on the cover page of this prospectus, the number of ADSs and ordinary shares listed next to its name in the following tables, respectively:

Our ADSs are listed on the Nasdaq Global Market under the symbol “ZLAB.”

Our ordinary shares are listed on the Main Board of The Stock Exchange of Hong Kong Limited under the symbol “9688.”

The underwriters are committed to purchase all the ADSs and ordinary shares offered by us if they purchase any ADSs or ordinary shares. Each underwriting agreement also provides that if an underwriter defaults, the purchase commitments of non-defaulting underwriters may also be increased or the offering of the relevant series may be terminated.

The underwriters propose to offer the ADSs directly to the public at the public offering price per ADS set forth on the cover page of this prospectus and to certain dealers at that price less a concession not in excess of $4.050 per ADS. The underwriters propose to offer the ordinary shares directly to the public at the public offering price per ordinary share set forth on the cover page of this prospectus and to certain dealers at that price less a concession not in excess of $4.050 per ordinary share (equivalent to approximately HK$31.4334). After the initial offering of the ADSs and ordinary shares to the public, the offering price and other selling terms may be changed by the underwriters. Sales of ADSs and ordinary shares made outside of the United States may be made by affiliates of the underwriters.

The underwriters have an option to buy up to 716,400 additional ADSs from us. The underwriters have 30 days from the date of this prospectus to exercise this option to purchase additional ADSs, which option will only be settled in ADSs. If any ADSs are purchased with this option to purchase additional ADSs, the underwriters will purchase ADSs in approximately the same proportion as shown in the table above. If any additional ADSs are purchased, the underwriters will offer the additional ADSs on the same terms as those on which the ADSs are being offered. The underwriters do not have an option to purchase additional ordinary shares from us.

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The underwriting fee is equal to the public offering price per ADS or ordinary share, as applicable, less the amount paid by the underwriters to us per ADS or per ordinary share, as applicable. The underwriting fee is $6.75 per ADS and HK$52.39 per ordinary share. The following table shows the per ADS and per ordinary share and total underwriting discounts and commissions to be paid to the underwriters assuming both no exercise and full exercise of the underwriters’ option to purchase additional ADSs.

We estimate that the total expenses of this offering, including registration, filing and listing fees, printing fees and legal and accounting expenses, but excluding the underwriting discounts and commissions, will be approximately $823,000. We have also agreed to reimburse the underwriters for certain of their expenses in an amount up to $45,000.

A prospectus in electronic format may be made available on the web sites maintained by one or more underwriters, or selling group members, if any, participating in the offering. The underwriters may agree to allocate a number of ADSs or ordinary shares, as applicable, to underwriters and selling group members for sale to their online brokerage account holders. Internet distributions will be allocated by the representatives to underwriters and selling group members that may make Internet distributions on the same basis as other allocations.

We have agreed that we will not (i) offer, pledge, announce the intention to sell, sell, contract to sell, sell any option or contract to purchase, purchase any option or contract to sell, grant any option, right or warrant to purchase or otherwise transfer or dispose of, directly or indirectly, or file with the SEC a registration statement under the Securities Act relating to, any ADSs or ordinary shares or securities convertible into or exchangeable or exercisable for any ADSs or ordinary shares or publicly disclose the intention to make any offer, sale, pledge, disposition or filing (other than, for the avoidance of doubt, the ADSs and ordinary shares to be sold in this offering), or (ii) enter into any swap or other arrangement that transfers all or a portion of the economic consequences associated with the ownership of any ADSs or ordinary shares or any such other securities (regardless of whether any of these transactions are to be settled by the delivery of ADSs, ordinary shares, or such other securities, in cash or otherwise), in each case without the prior written consent of J.P. Morgan Securities LLC and Goldman Sachs & Co. LLC for a period of 90 days after the date of this prospectus, other than (i) the ADSs to be sold hereunder, (ii) any ordinary shares or ADSs issued upon the exercise of options granted under our equity incentive plans, (iii) any options and other awards granted under our equity incentive plans, (iv) the issuance of securities convertible into or exercisable or exchangeable for ordinary shares in connection with the hiring of new employees provided that such securities cannot be so converted, exercised or exchanged within the 90-day restricted period, (v) any ordinary shares issued pursuant to the conversion or exchange of convertible or exchangeable securities, including preferred shares and warrants, as described in this registration statement of which this prospectus forms a part, (vi) the filing of any registration statement on Form S-8 relating to any benefit plans or arrangements disclosed in this registration statement of which this prospectus forms a part and the issuance of securities registered pursuant thereto, or (vii) any ordinary shares or securities exercisable for, convertible into or exchangeable for ordinary shares in connection with any acquisition, collaboration, licensing or other joint venture or strategic transaction or any debt financing transaction involving the Company; provided that, in the case of clauses (ii), (iii), (v) and (vii), (x) such issuances shall not in the aggregate be greater than 10% of the total outstanding ordinary shares immediately following the completion of this offering of ADSs which, for the avoidance of doubt, includes the ordinary shares issuable upon the conversion of preferred shares in connection with this offering, and (y) the recipients of such shares agree to be bound by a lockup letter in the form executed by directors and officers.

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Our executive officers, directors and a significant shareholder have entered into lock-up agreements with the underwriters prior to the commencement of this offering pursuant to which each of these persons or entities, with limited exceptions, for a period of 90 days after the date of this prospectus (the “Restricted Period”), may not, without the prior written consent of J.P. Morgan Securities LLC and Goldman Sachs & Co. LLC (1) offer, pledge, sell, contract to sell, sell any option or contract to purchase, purchase any option or contract to sell, grant any option, right or warrant to purchase, or otherwise transfer or dispose of, directly or indirectly, any ADSs or ordinary shares or any securities convertible into or exercisable or exchangeable for our ADSs or ordinary shares (including, without limitation, ADSs or such other securities which may be deemed to be beneficially owned by such directors, executive officers, managers and members in accordance with the rules and regulations of the SEC and securities which may be issued upon exercise of a stock option or warrant), or publicly disclose the intention to make any offer, sale, pledge or disposition; (2) enter into any swap or other agreement that transfers, in whole or in part, any of the economic consequences of ownership of the ADSs or ordinary shares or such other securities, whether any such transaction described in clause (1) or (2) above is to be settled by delivery of ADSs or ordinary shares or such other securities, in cash or otherwise, or (3) make any demand for or exercise any right with respect to the registration of any ADSs or ordinary shares or any security convertible into or exercisable or exchangeable for our ADSs or ordinary shares.

The restrictions described in the immediately preceding paragraph do not apply to, among other items:

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We have agreed to indemnify the underwriters against certain liabilities, including liabilities under the Securities Act of 1933.

In connection with this offering, the underwriters may engage in stabilizing transactions, which involves making bids for, purchasing and selling ADSs in the open market for the purpose of preventing or retarding a decline in the market price of the ADSs while this offering is in progress. These stabilizing transactions may include making short sales of the ADSs, which involves the sale by the underwriters of a greater number of ADSs than they are required to purchase in this offering, and purchasing ADSs on the open market to cover positions created by short sales. Short sales may be “covered” shorts, which are short positions in an amount not greater than the underwriters’ option to purchase additional ADSs referred to above, or may be “naked” shorts, which are short positions in excess of that amount. The underwriters may close out any covered short position either by exercising their option to purchase additional ADSs, in whole or in part, or by purchasing ADSs in the open market. In making this determination, the underwriters will consider, among other things, the price of ADSs available for purchase in the open market compared to the price at which the underwriters may purchase ADSs through the option to purchase additional ADSs. A naked short position is more likely to be created if the underwriters are concerned that there may be downward pressure on the price of the ADSs in the open market that could adversely affect investors who purchase in this offering. To the extent that the underwriters create a naked short position, they will purchase ADSs in the open market to cover the position.

The underwriters have advised us that, pursuant to Regulation M of the Securities Act of 1933, they may also engage in other activities that stabilize, maintain or otherwise affect the price of the ADSs, including the imposition of penalty bids. This means that if the representatives of the underwriters purchase ADSs in the open market in stabilizing transactions or to cover short sales, the representatives can require the underwriters that sold those ADSs as part of this offering to repay the underwriting discount received by them.

These activities may have the effect of raising or maintaining the market price of the ADSs or preventing or retarding a decline in the market price of the ADSs, and, as a result, the price of the ADSs may be higher than the price that otherwise might exist in the open market. If the underwriters commence these activities, they may discontinue them at any time. The underwriters may carry out these transactions on the Nasdaq Global Market, in the over-the-counter market or otherwise.

Other than in the United States, no action has been taken by us or the underwriters that would permit a public offering of the securities offered by this prospectus in any jurisdiction where action for that purpose is required. The securities offered by this prospectus may not be offered or sold, directly or indirectly, nor may this prospectus or any other offering material or advertisements in connection with the offer and sale of any such securities be distributed or published in any jurisdiction, except under circumstances that will result in compliance with the applicable rules and regulations of that jurisdiction. Persons into whose possession this prospectus comes are advised to inform themselves about and to observe any restrictions relating to the offering and the distribution of this prospectus. This prospectus does not constitute an offer to sell or a solicitation of an offer to buy any securities offered by this prospectus in any jurisdiction in which such an offer or a solicitation is unlawful.

The underwriters and their respective affiliates are full service financial institutions engaged in various activities, which may include securities trading, commercial and investment banking, financial advisory, investment management, investment research, principal investment, hedging, financing and brokerage activities. Certain of the underwriters and their respective affiliates have, from time to time, performed, and may in the future perform, various financial advisory, commercial banking and investment banking services for us and our affiliates, for

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which they received or will receive customary fees and expenses. In the ordinary course of their various business activities, the underwriters and their respective affiliates may make or hold a broad array of investments and actively trade debt and equity securities (or related derivative securities) and financial instruments (including bank loans) for their own account and for the accounts of their customers, and such investment and securities activities may involve our securities and/or instruments. The underwriters and their respective affiliates may also make investment recommendations and/or publish or express independent research views in respect of such securities or instruments and may at any time hold, or recommend to clients that they acquire, long and/or short positions in such securities and instruments.

Notice to all prospective investors

In purchasing the ordinary shares and/or ADSs, save as otherwise permitted under the Listing Rules or within the scope of any other waivers or consents granted or to be granted by the Hong Kong Stock Exchange, you will be deemed to have represented to and agreed as follows:

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Notice to prospective investors in Australia

This prospectus:

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The ADSs or ordinary shares may not be directly or indirectly offered for subscription or purchased or sold, and no invitations to subscribe for or buy the ADSs or ordinary shares may be issued, and no draft or definitive offering memorandum, advertisement or other offering material relating to any ADSs or ordinary shares may be distributed in Australia, except where disclosure to investors is not required under Chapter 6D of the Corporations Act or is otherwise in compliance with all applicable Australian laws and regulations. By submitting an application for the ADSs or ordinary shares, you represent and warrant to us that you are an Exempt Investor.

As any offer of ADSs or ordinary shares under this document will be made without disclosure in Australia under Chapter 6D.2 of the Corporations Act, the offer of those securities for resale in Australia within 12 months may, under section 707 of the Corporations Act, require disclosure to investors under Chapter 6D.2 if none of the exemptions in section 708 applies to that resale. By applying for the ADSs or ordinary shares you undertake to us that you will not, for a period of 12 months from the date of issue of the ADSs or ordinary shares, offer, transfer, assign or otherwise alienate those securities to investors in Australia except in circumstances where disclosure to investors is not required under Chapter 6D.2 of the Corporations Act or where a compliant disclosure document is prepared and lodged with ASIC.

Notice to prospective investors in Bermuda

ADSs and ordinary shares may be offered or sold in Bermuda only in compliance with the provisions of the Investment Business Act of 2003 of Bermuda which regulates the sale of securities in Bermuda. Additionally, non-Bermudian persons (including companies) may not carry on or engage in any trade or business in Bermuda unless such persons are permitted to do so under applicable Bermuda legislation.

Notice to prospective investors in the British Virgin Islands

The ADSs and ordinary shares are not being, and may not be offered to the public or to any person in the British Virgin Islands for purchase or subscription by or on our behalf. The ADSs and ordinary shares may be offered to companies incorporated under the BVI Business Companies Act, 2004 (British Virgin Islands), “BVI Companies”), but only where the offer will be made to, and received by, the relevant BVI Company entirely outside of the British Virgin Islands.

Notice to prospective investors in Canada

The ADSs and ordinary shares may be sold only to purchasers purchasing, or deemed to be purchasing, as principal that are accredited investors, as defined in National Instrument 45-106 Prospectus Exemptions or subsection 73.3(1) of the Securities Act (Ontario), and are permitted clients, as defined in National Instrument 31-103 Registration Requirements, Exemptions and Ongoing Registrant Obligations. Any resale of the ADSs or ordinary shares must be made in accordance with an exemption from, or in a transaction not subject to, the prospectus requirements of applicable securities laws.

Securities legislation in certain provinces or territories of Canada may provide a purchaser with remedies for rescission or damages if this prospectus (including any amendment thereto) contains a misrepresentation, provided that the remedies for rescission or damages are exercised by the purchaser within the time limit prescribed by the securities legislation of the purchaser’s province or territory. The purchaser should refer to any applicable provisions of the securities legislation of the purchaser’s province or territory for particulars of these rights or consult with a legal advisor.

Pursuant to section 3A.3 of National Instrument 33-105 Underwriting Conflicts (NI 33-105), the underwriters are not required to comply with the disclosure requirements of NI 33-105 regarding underwriter conflicts of interest in connection with this offering.

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Notice to prospective investors in China

This Prospectus will not be circulated or distributed in the People’s Republic of China (the “PRC”) and the ADSs and ordinary shares will not be offered or sold, and will not be offered or sold to any person for re-offering or resale directly or indirectly to any residents of the PRC except pursuant to any applicable laws and regulations of the PRC. Neither this Prospectus nor any advertisement or other offering material may be distributed or published in the PRC, except under circumstances that will result in compliance with applicable laws and regulations.

Notice to prospective investors in the European Economic Area

In relation to each Member State of the European Economic Area (each, a “Relevant Member State”), an offer to the public of any ADSs or ordinary shares may not be made in that Relevant Member State, except that an offer to the public in that Relevant Member State of any shares may be made at any time under the following exemptions under the Prospectus Regulation:

provided that no such offer of shares shall result in a requirement for the Issuer or any representative to publish a prospectus pursuant to Article 3 of the Prospectus Regulation or a supplemental prospectus pursuant to Article 23 of the Prospectus Regulation. For the purposes of this provision, the expression an “offer to the public” in relation to any ADSs or ordinary shares in any Relevant Member State means the communication in any form and by any means of sufficient information on the terms of the offer and any ADSs or ordinary shares to be offered so as to enable an investor to decide to purchase or subscribe for any ADSs or ordinary shares, and the expression “Prospectus Regulation” means Regulation (EU) 2017/1129.

Notice to prospective investors in Hong Kong

The ADSs and ordinary shares have not been offered or sold and will not be offered or sold in Hong Kong, by means of any document, other than (a) to “professional investors” as defined in the Securities and Futures Ordinance (Cap. 571) of Hong Kong and any rules made under that Ordinance; or (b) in other circumstances which do not result in the document being a “prospectus” as defined in the Companies (Winding Up and Miscellaneous Provisions) Ordinance (Cap. 32) of Hong Kong or which do not constitute an offer to the public within the meaning of that Ordinance. No advertisement, invitation or document relating to the ADSs and ordinary shares has been or may be issued or has been or may be in the possession of any person for the purposes of issue, whether in Hong Kong or elsewhere, which is directed at, or the contents of which are likely to be accessed or read by, the public of Hong Kong (except if permitted to do so under the securities laws of Hong Kong) other than with respect to ADSs and ordinary shares which are or are intended to be disposed of only to persons outside Hong Kong or only to “professional investors” as defined in the Securities and Futures Ordinance and any rules made under that Ordinance.

Notice to prospective investors in Japan

The ADSs and ordinary shares have not been and will not be registered under the Financial Instruments and Exchange Act of Japan (Act No. 25 of 1948, as amended), or the FIEA. The ADSs and ordinary shares may not be offered or sold, directly or indirectly, in Japan or to or for the benefit of any resident of Japan (including any person resident in Japan or any corporation or other entity organized under the laws of Japan) or to others for reoffering or resale, directly or indirectly, in Japan or to or for the benefit of any resident of Japan, except pursuant to an exemption from the registration requirements of the FIEA and otherwise in compliance with any relevant laws and regulations of Japan.

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Notice to prospective investors in Korea

The ADSs and ordinary shares have not been and will not be registered under the Financial Investments Services and Capital Markets Act of Korea and the decrees and regulations thereunder (the “FSCMA”), and the ADSs and ordinary shares have been and will be offered in Korea as a private placement under the FSCMA. None of the ADSs and ordinary shares may be offered, sold or delivered directly or indirectly, or offered or sold to any person for re-offering or resale, directly or indirectly, in Korea or to any resident of Korea except pursuant to the applicable laws and regulations of Korea, including the FSCMA and the Foreign Exchange Transaction Law of Korea and the decrees and regulations thereunder (the “FETL”). The ADSs and ordinary shares have not been listed on any of securities exchanges in the world including, without limitation, the Korea Exchange in Korea. Furthermore, the purchaser of the ADSs or ordinary shares shall comply with all applicable regulatory requirements (including but not limited to requirements under the FETL) in connection with the purchase of the shares. By the purchase of the ADSs or ordinary shares, the relevant holder thereof will be deemed to represent and warrant that if it is in Korea or is a resident of Korea, it purchased the ADSs or ordinary shares pursuant to the applicable laws and regulations of Korea.

Notice to prospective investors in Malaysia

No prospectus or other offering material or document in connection with the offer and sale of the ADSs and ordinary shares has been or will be registered with the Securities Commission of Malaysia (“Commission”) for the Commission’s approval pursuant to the Capital Markets and Services Act 2007. Accordingly, this prospectus and any other document or material in connection with the offer or sale, or invitation for subscription or purchase, of the ADSs and ordinary shares may not be circulated or distributed, nor may the ADSs and ordinary shares be offered or sold, or be made the subject of an invitation for subscription or purchase, whether directly or indirectly, to persons in Malaysia other than (i) a closed end fund approved by the Commission; (ii) a holder of a Capital Markets Services License; (iii) a person who acquires the ADSs and ordinary shares, as principal, if the offer is on terms that the ADSs and ordinary shares may only be acquired at a consideration of not less than RM250,000 (or its equivalent in foreign currencies) for each transaction; (iv) an individual whose total net personal assets or total net joint assets with his or her spouse exceeds RM3 million (or its equivalent in foreign currencies), excluding the value of the primary residence of the individual; (v) an individual who has a gross annual income exceeding RM300,000 (or its equivalent in foreign currencies) per annum in the preceding twelve months; (vi) an individual who, jointly with his or her spouse, has a gross annual income of RM400,000 (or its equivalent in foreign currencies), per annum in the preceding twelve months; (vii) a corporation with total net assets exceeding RM10 million (or its equivalent in a foreign currencies) based on the last audited accounts; (viii) a partnership with total net assets exceeding RM10 million (or its equivalent in foreign currencies); (ix) a bank licensee or insurance licensee as defined in the Labuan Financial Services and Securities Act 2010; (x) an Islamic bank licensee or takaful licensee as defined in the Labuan Financial Services and Securities Act 2010; and (xi) any other person as may be specified by the Commission; provided that, in the each of the preceding categories (i) to (xi), the distribution of the ADSs and ordinary shares is made by a holder of a Capital Markets Services License who carries on the business of dealing in securities. The distribution in Malaysia of this prospectus is subject to Malaysian laws. This prospectus does not constitute and may not be used for the purpose of public offering or an issue, offer for subscription or purchase, invitation to subscribe for or purchase any securities requiring the registration of a prospectus with the Commission under the Capital Markets and Services Act 2007.

Notice to prospective investors in Saudi Arabia

This document may not be distributed in the Kingdom of Saudi Arabia except to such persons as are permitted under the Offers of Securities Regulations as issued by the board of the Saudi Arabian Capital Market Authority (“CMA”) pursuant to resolution number 2-11-2004 dated 4 October 2004 as amended by resolution number 1-28-2008, as amended (the “CMA Regulations”). The CMA does not make any representation as to the accuracy or completeness of this document and expressly disclaims any liability whatsoever for any loss arising from, or incurred in reliance upon, any part of this document. Prospective purchasers of the securities offered hereby should conduct their own due diligence on the accuracy of the information relating to the securities. If you do not understand the contents of this document, you should consult an authorised financial adviser.

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Notice to prospective investors in Singapore

This prospectus has not been registered as a prospectus with the Monetary Authority of Singapore. Accordingly, this prospectus and any other document or material in connection with the offer or sale, or invitation for subscription or purchase, of the ADSs and ordinary shares may not be circulated or distributed, nor may the shares be offered or sold, or be made the subject of an invitation for subscription or purchase, whether directly or indirectly, to persons in Singapore other than (i) to an institutional investor (as defined under Section 4A of the Securities and Futures Act, Chapter 289 of Singapore (the “SFA”)) under Section 274 of the SFA, (ii) to a relevant person (as defined in Section 275(2) of the SFA) pursuant to Section 275(1) of the SFA, or any person pursuant to Section 275(1A) of the SFA, and in accordance with the conditions specified in Section 275 of the SFA or (iii) otherwise pursuant to, and in accordance with the conditions of, any other applicable provision of the SFA, in each case subject to conditions set forth in the SFA.

Where the shares are subscribed or purchased under Section 275 of the SFA by a relevant person which is a corporation (which is not an accredited investor (as defined in Section 4A of the SFA)) the sole business of which is to hold investments and the entire share capital of which is owned by one or more individuals, each of whom is an accredited investor, the securities (as defined in Section 239(1) of the SFA) of that corporation shall not be transferable for 6 months after that corporation has acquired the ADSs and ordinary shares under Section 275 of the SFA except: (1) to an institutional investor under Section 274 of the SFA or to a relevant person (as defined in Section 275(2) of the SFA), (2) where such transfer arises from an offer in that corporation’s securities pursuant to Section 275(1A) of the SFA, (3) where no consideration is or will be given for the transfer, (4) where the transfer is by operation of law, (5) as specified in Section 276(7) of the SFA, or (6) as specified in Regulation 32 of the Securities and Futures (Offers of Investments) (Shares and Debentures) Regulations 2005 of Singapore (“Regulation 32”).

Where the ADSs and ordinary shares are subscribed or purchased under Section 275 of the SFA by a relevant person which is a trust (where the trustee is not an accredited investor (as defined in Section 4A of the SFA)) whose sole purpose is to hold investments and each beneficiary of the trust is an accredited investor, the beneficiaries’ rights and interest (howsoever described) in that trust shall not be transferable for 6 months after that trust has acquired the shares under Section 275 of the SFA except: (1) to an institutional investor under Section 274 of the SFA or to a relevant person (as defined in Section 275(2) of the SFA), (2) where such transfer arises from an offer that is made on terms that such rights or interest are acquired at a consideration of not less than $200,000 (or its equivalent in a foreign currency) for each transaction (whether such amount is to be paid for in cash or by exchange of securities or other assets), (3) where no consideration is or will be given for the transfer, (4) where the transfer is by operation of law, (5) as specified in Section 276(7) of the SFA, or (6) as specified in Regulation 32.

Singapore Securities and Futures Act Product Classification—Solely for the purposes of its obligations pursuant to Sections 309B(1)(a) and 309B(1)(c) of the SFA, the issuer has determined, and hereby notifies all relevant persons (as defined in Section 309A of the SFA) that the ADSs and ordinary shares are “prescribed capital markets products” (as defined in the Securities and Futures (Capital Markets Products) Regulations 2018) and “Excluded Investment Products” (as defined in MAS Notice SFA 04-N12: Notice on the Sale of Investment Products and MAS Notice FAA-N16: Notice on Recommendations on Investment Products).

Notice to prospective investors in South Africa

Due to restrictions under the securities laws of South Africa, no “offer to the public” (as such term is defined in the South African Companies Act, No. 71 of 2008 (as amended or re-enacted) (the “South African Companies Act”)) is being made in connection with the issue of the ADSs or ordinary shares in South Africa. Accordingly, this document does not, nor is it intended to, constitute a “registered prospectus” (as that term is defined in the South African Companies Act) prepared and registered under the South African Companies Act and has not been approved by, and/or filed with, the South African Companies and Intellectual Property Commission or any other regulatory authority in South Africa. The ADSs and ordinary shares are not offered, and the offer shall not be

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transferred, sold, renounced or delivered, in South Africa or to a person with an address in South Africa, unless one or other of the following exemptions stipulated in section 96 (1) applies:

Section 96 (1)(a)

The offer, transfer, sale, renunciation or delivery is to:

Section 96 (1)(b)

The total contemplated acquisition cost of the securities, for any single addressee acting as principal is equal to or greater than ZAR1,000,000 or such higher amount as may be promulgated by notice in the Government Gazette of South Africa pursuant to section 96(2)(a) of the South African Companies Act.

Information made available in this prospectus should not be considered as “advice” as defined in the South African Financial Advisory and Intermediary Services Act, 2002

Notice to prospective investors in Switzerland

The ADSs and ordinary shares may not be publicly offered in Switzerland and will not be listed on the SIX Swiss Exchange (“SIX”) or on any other stock exchange or regulated trading facility in Switzerland. This document does not constitute a prospectus within the meaning of, and has been prepared without regard to the disclosure standards for issuance prospectuses under art. 652a or art. 1156 of the Swiss Code of Obligations or the disclosure standards for listing prospectuses under art. 27 ff. of the SIX Listing Rules or the listing rules of any other stock exchange or regulated trading facility in Switzerland. Neither this document nor any other offering or marketing material relating to the ADSs or ordinary shares or the offering may be publicly distributed or otherwise made publicly available in Switzerland.

Neither this document nor any other offering or marketing material relating to the offering, us or the ADSs and ordinary shares have been or will be filed with or approved by any Swiss regulatory authority. In particular, this document will not be filed with, and the offer of ADSs and ordinary shares will not be supervised by, the Swiss Financial Market Supervisory Authority FINMA (FINMA), and the offer of ADSs and ordinary shares has not been and will not be authorized under the Swiss Federal Act on Collective Investment Schemes (“CISA”). The investor protection afforded to acquirers of interests in collective investment schemes under the CISA does not extend to acquirers of ADSs or ordinary shares.

Notice to prospective investors in Taiwan

The ADSs and ordinary shares have not been and will not be registered with the Financial Supervisory Commission of Taiwan pursuant to relevant securities laws and regulations and may not be sold, issued or

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offered within Taiwan through a public offering or in circumstances which constitutes an offer within the meaning of the Securities and Exchange Act of Taiwan that requires a registration or approval of the Financial Supervisory Commission of Taiwan. No person or entity in Taiwan has been authorised to offer, sell, give advice regarding or otherwise intermediate the offering and sale of the ADSs and ordinary shares in Taiwan.

Notice to prospective investors in the United Arab Emirates

The ADSs and ordinary shares have not been, and are not being, publicly offered, sold, promoted or advertised in the United Arab Emirates (including the Dubai International Financial Centre) other than in compliance with the laws of the United Arab Emirates (and the Dubai International Financial Centre) governing the issue, offering and sale of securities. Further, this prospectus does not constitute a public offer of securities in the United Arab Emirates (including the Dubai International Financial Centre) and is not intended to be a public offer. This prospectus has not been approved by or filed with the Central Bank of the United Arab Emirates, the Securities and Commodities Authority or the Dubai Financial Services Authority.

Notice to prospective investors in the United Kingdom

An offer to the public of any ADSs or ordinary shares may not be made in the United Kingdom, except that an offer to the public in the United Kingdom of any ADSs or ordinary shares may be made at any time under the following exemptions under the UK Prospectus Regulation:

provided that no such offer of ADSs or ordinary shares shall result in a requirement for the Issuer or any representative to publish a prospectus pursuant to section 85 of the FSMA or a supplemental prospectus pursuant to Article 23 of the UK Prospectus Regulation. For the purposes of this provision, the expression an “offer to the public” in relation to any ADSs or ordinary shares in the United Kingdom means the communication in any form and by any means of sufficient information on the terms of the offer and any ADSs or ordinary shares to be offered so as to enable an investor to decide to purchase or subscribe for any ADSs or ordinary shares, and the expression “UK Prospectus Regulation” means Regulation (EU) 2017/1129 as it forms part of domestic law by virtue of the European Union (Withdrawal) Act 2018.

In the United Kingdom, this prospectus is being distributed only to, and is directed only at, persons who are “qualified investors” (as defined in the UK Prospectus Regulation) who are (i) persons having professional experience in matters relating to investments falling within Article 19(5) of the Financial Services and Markets Act 2000 (Financial Promotion) Order 2005 (as amended, the “Order”), or (ii) high net worth entities falling within Article 49(2)(a) to (d) of the Order, or (iii) persons to whom it would otherwise be lawful to distribute it, all such persons together being referred to as “Relevant Persons”. In the United Kingdom, the ADSs or ordinary shares are only available to, and any invitation, offer or agreement to subscribe, purchase or otherwise acquire such ADSs or ordinary shares will be engaged in only with, Relevant Persons. This prospectus and its contents are confidential and should not be distributed, published or reproduced (in whole or in part) or disclosed by any recipients to any other person in the United Kingdom. Any person in the United Kingdom that is not a Relevant Person should not act or rely on this prospectus or its contents. The shares are not being offered to the public in the United Kingdom.

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Exchange between ordinary shares trading in Hong Kong and ADSs

Register of members and stamp duty

Our principal register of members will be maintained by our principal share registrar in the Cayman Islands, and our Hong Kong register of members will be maintained by the Hong Kong share registrar, Computershare Hong Kong Investor Services Limited (the “Hong Kong Share Registrar”), in Hong Kong.

Dealings in our shares registered on our Hong Kong share register will be subject to Hong Kong stamp duty. The stamp duty is charged to each of the seller and purchaser at the ad valorem rate of 0.1% of the consideration for, or (if greater) the value of, our shares transferred. In other words, a total of 0.2% is currently payable on a typical sale and purchase transaction of our shares. In addition, a fixed duty of HK$5.00 is charged on each instrument of transfer (if required).

To facilitate deposits of shares to and withdrawals of shares from the ADS facility, we have moved a portion of our issued shares, including all of the shares deposited in our ADS program, from our Cayman share register to our Hong Kong share register. It is unclear whether, as a matter of Hong Kong law, the trading of ADSs representing shares constitutes a sale or purchase of the underlying Hong Kong-registered shares that is subject to Hong Kong stamp duty. We advise investors to consult their own tax advisors on this matter. See “Risk Factors—Risks related to our Ordinary Shares, the ADSs, and this offering—There is uncertainty as to whether Hong Kong stamp duty will apply to the trading or conversion of our ADSs following our initial public offering in Hong Kong and Listing of our ordinary shares on the Hong Kong Stock Exchange”.

Dealings and settlement of ordinary shares in Hong Kong

Our ordinary shares trade on the Hong Kong Stock Exchange in board lots of 50 shares. Dealings in our ordinary shares on the Hong Kong Stock Exchange will be conducted in Hong Kong dollars.

The transaction costs of dealings in our ordinary shares on the Hong Kong Stock Exchange include:

Investors must settle their trades executed on the Hong Kong Stock Exchange through their brokers directly or through custodians. For an investor who has deposited his/her shares in his/her stock account or in his/her designated CCASS participant’s stock account maintained with CCASS, settlement will be effected in CCASS in

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accordance with the General Rules of CCASS and CCASS Operational Procedures in effect from time to time. For an investor who holds the physical certificates, settlement certificates and the duly executed transfer forms must be delivered to his/her broker or custodian before the settlement date.

Exchange Between Ordinary Shares Trading in Hong Kong and ADSs

In connection with the initial public offering of our shares in Hong Kong, we have established a branch register of members in Hong Kong, or the Hong Kong share register, which will be maintained by our Hong Kong share registrar, Computershare Hong Kong Investor Services Limited. Our principal register of members, or the Cayman share register, will continue to be maintained by our principal share registrar, International Corporation Services Ltd.

As described in further detail below, holders of ordinary shares will be able to exchange those shares for ADSs and vice versa.

Our ADSs

Our ADSs representing our ordinary shares are currently traded on Nasdaq. Dealings in our ADSs on Nasdaq are conducted in U.S. Dollars.

ADSs may be held either:

Depositing Shares trading in Hong Kong for delivery of ADSs

An investor who holds the shares registered in Hong Kong and wishes to receive delivery of ADSs that trade on the Nasdaq must deposit or have his/her broker deposit the shares with the depositary’s Hong Kong custodian, Citibank, N.A., Hong Kong, or the custodian, in exchange for ADSs.

A deposit of shares trading in Hong Kong in exchange for ADSs involves the following procedures:

For shares deposited in CCASS, under normal circumstances, the above steps generally require two business days, provided that the investor has provided timely and complete instructions. For shares held outside CCASS in physical form, the above steps may take 14 business days, or more, to complete. Temporary delays may arise. For example, the transfer books of the depositary may from time to time be closed to ADS issuances. The investor will be unable to trade the ADSs until the procedures are completed.

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Surrender of ADSs for delivery of Shares trading in Hong Kong

An investor who holds ADSs and wishes to receive shares that trade on the Hong Kong Stock Exchange must cancel the ADSs the investor holds and withdraw the shares from our ADS program and cause his/her broker or other financial institution to trade such shares on the Hong Kong Stock Exchange.

An investor that holds ADSs indirectly through a broker or other financial institution should follow the procedures of the broker or financial institution and instruct the broker to arrange for cancellation of the ADSs, and transfer of the underlying shares from the depositary’s account with the custodian within the CCASS system to the investor’s Hong Kong stock account.

For investors holding ADSs directly, the following steps must be taken:

For the shares to be received in CCASS, under normal circumstances, the above steps generally require two business days, provided that the investor has provided timely and complete instructions. For the shares to be received outside CCASS in physical form, the above steps may take 14 business days, or more, to complete. The investor will be unable to trade the shares on the Hong Kong Stock Exchange until the procedures are completed.

Temporary delays may arise. For example, the transfer books of the depositary may from time to time be closed to ADS cancelations. In addition, completion of the above steps and procedures for delivery of shares in a CCASS account is subject to there being a sufficient number of shares on the Hong Kong share register to facilitate a withdrawal from the ADS program directly into the CCASS system. We are not under any obligation to maintain or increase the number of shares on the Hong Kong share register to facilitate such withdrawals.

Depositary requirements

Before the depositary delivers ADSs or permits withdrawal of the shares, the depositary may require:

The depositary may refuse to deliver, transfer, or register issuances, transfers and cancelations of ADSs generally when the transfer books of the depositary or of the Hong Kong share registrar are closed or at any time if the depositary or we determine it advisable to do so.

All costs attributable to the transfer of the shares to effect a withdrawal from or deposit of the shares into our ADS program will be borne by the investor requesting the transfer or deposit. In particular, holders of shares and ADSs should note that the Hong Kong share registrar will charge between HK$2.50 to HK$20, depending on the speed of service (or such higher fee as may from time to time be permitted under the Listing Rules), for each

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transfer of the shares from one registered owner to another, each share certificate canceled or issued by it and any applicable fee as stated in the share transfer forms used in Hong Kong. In addition, holders of the shares and ADSs must pay up to $5.00 per 100 ADSs (or portion thereof) for each issuance of ADSs and each cancelation of ADSs, as the case may be, in connection with the deposit of the shares into, or withdrawal of the shares from, the ADS facility.

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Taxation

The following is a summary of the material Cayman Islands, PRC and United States federal income tax consequences relevant to an investment in the ADSs and ordinary shares. The discussion is not intended to be, nor should it be construed as, legal or tax advice to any particular prospective purchaser. The discussion is based on laws and relevant interpretations thereof as of the date of this prospectus, all of which are subject to change or different interpretations, possibly with retroactive effect. The discussion does not address U.S. state or local tax laws, or tax laws of jurisdictions other than the Cayman Islands, the People’s Republic of China and the United States. You should consult your own tax advisors with respect to the consequences of acquisition, ownership and disposition of the ADSs and ordinary shares.

Cayman Islands taxation

The Cayman Islands currently levies no taxes on individuals or corporations based upon profits, income, gains or appreciation and there is no taxation in the nature of inheritance tax or estate duty. There are no other taxes likely to be material to us or our shareholders or ADS-holders levied by the government of the Cayman Islands except for stamp duties which may be applicable on instruments executed in, or after execution brought within the jurisdiction of the Cayman Islands. The Cayman Islands is not party to any double tax treaties that are applicable to any payments made to or by us. There are no exchange control regulations or currency restrictions in the Cayman Islands.

People’s Republic of China taxation

We are a holding company incorporated in the Cayman Islands.

Under the EIT Law and its implementation rules, an enterprise established outside of China with a “de facto management body” within China is considered a “resident enterprise,” and will be subject to the enterprise income tax on its global income at the rate of 25%. The implementation rules define the term “de facto management body” as the body that exercises full and substantial control and overall management over the business, productions, personnel, accounts and properties of an enterprise. In 2009, the State Administration of Taxation issued SAT Circular 82, which provides certain specific criteria for determining whether the “de facto management body” of a PRC-controlled enterprise that is incorporated offshore is located in China. Although this circular only applies to offshore enterprises controlled by PRC enterprises or PRC enterprise groups, not those controlled by PRC individuals or foreigners, the criteria set forth in the circular may reflect the State Administration of Taxation’s general position on how the “de facto management body” text should be applied in determining the tax resident status of all offshore enterprises. According to SAT Circular 82, all offshore enterprises controlled by a PRC enterprise or a PRC enterprise will be regarded as a PRC tax resident by virtue of having its “de facto management body” in China only if all of the following conditions are met:

We believe that none of Zai Lab Limited and its subsidiaries outside of China is a PRC resident enterprise for PRC tax purposes. Zai Lab Limited is not controlled by a PRC enterprise or PRC enterprise group, and we do not believe that Zai Lab Limited meets all of the conditions above. Zai Lab Limited is a company incorporated outside China. As a holding company, some of its key assets are located, and its records (including the resolutions of its board of directors and the resolutions of its shareholders) are maintained, outside China. For the

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same reasons, we believe our other subsidiaries outside of China are also not PRC resident enterprises. However, the tax resident status of an enterprise is subject to determination by the PRC tax authorities and uncertainties remain with respect to the interpretation of the term “de facto management body.”

If the PRC tax authorities determine that Zai Lab Limited is a PRC resident enterprise for EIT purposes, we may be required to withhold tax at a rate of 10% on dividends we pay to our shareholders, including holders of our ADSs, that are non-resident enterprises. In addition, non-resident enterprise shareholders (including our ADS holders) may be subject to a 10% PRC withholding tax on gains realized on the sale or other disposition of ADS or ordinary shares, if such income is treated as sourced from within China. Furthermore, gains derived by our non-PRC individual shareholders from the sale of our shares and ADSs may be subject to a 20% PRC withholding tax. It is unclear whether our non-PRC individual shareholders (including our ADS holders) would be subject to any PRC tax (including withholding tax) on dividends received by such non-PRC individual shareholders in the event we are deemed to be a PRC resident enterprise. If any PRC tax were to apply to dividends realized by non-PRC individuals, it will generally apply at a rate of 20%. The PRC tax liability may be reduced under applicable tax treaties. However, it is unclear whether non-PRC shareholders of Zai Lab Limited would be able to claim the benefits of any tax treaty between their country of tax residence and China in the event that Zai Lab Limited is treated as a PRC resident enterprise.

Pursuant to the EIT Law and its implementation rules, if a non-resident enterprise has not set up an organization or establishment in China, or has set up an organization or establishment but the income derived has no actual connection with such organization or establishment, it will be subject to a withholding tax on its PRC-sourced income at a rate of 10%. Pursuant to the Arrangement between Mainland China and the Hong Kong Special Administrative Region for the Avoidance of Double Taxation and Tax Evasion on Income, the tax rate in respect to dividends paid by a PRC enterprise to a Hong Kong enterprise is reduced to 5% if the Hong Kong enterprise directly holds at least 25% of the PRC enterprise. Pursuant to the Notice of the State Administration of Taxation on the Issues concerning the Application of the Dividend Clauses of Tax Agreements, or SAT Circular 81, a Hong Kong resident enterprise must meet the following conditions, among others, in order to be eligible for the reduced tax rate: (i) it must directly own the required percentage of equity interests and voting rights in the PRC resident enterprise; and (ii) it must have directly owned such percentage in the PRC resident enterprise throughout the 12 months prior to receiving the dividends. Furthermore, the Administrative Measures for Non-Resident Enterprises to Enjoy Treatments under Tax Treaties became effective in January 2020, according to which, where non-resident enterprises judge by themselves that they meet the conditions for entitlement to reduced tax rate according to tax treaties, they may enjoy such entitlement after reporting required information to competent tax authorities provided that they shall collect and retain relevant documents for future reference and inspections. Accordingly, our subsidiary Zai Lab (Hong Kong) Limited may eligible for the 5% tax rate for the dividends it receives from its PRC incorporated subsidiaries if they satisfy the conditions prescribed under SAT Circular 81 and other relevant tax rules and regulations and complete the necessary government formalities. However, according to SAT Circular 81, if the relevant tax authorities determine our transactions or arrangements are for the primary purpose of enjoying a favorable tax treatment, the relevant tax authorities may adjust the favorable tax rate on dividends in the future. If our Cayman Islands holding company, Zai Lab Limited, is not deemed to be a PRC resident enterprise, holders of our ADSs and ordinary shares who are not PRC residents will not be subject to PRC income tax on dividends distributed by us or gains realized from the sale or other disposition of our shares or ADSs.

Material United States federal income tax considerations

The following are material U.S. federal income tax consequences to the U.S. Holders described below of owning and disposing of our ADSs or underlying ordinary shares. This discussion applies only to ADSs acquired in this offering (or the underlying ordinary shares) that are held by you as capital assets for U.S. federal income tax purposes. This discussion is not a comprehensive description of all of the tax considerations that may be relevant to you in your particular circumstances. In addition, it does not describe any alternative minimum or Medicare contribution tax considerations, or tax consequences applicable to you if you are subject to special rules, such as if you are:

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If you are classified as a partnership for U.S. federal income tax purposes, the U.S. federal income tax treatment of a partner will generally depend on the status of the partner and your activities. Partnerships holding ADSs or ordinary shares and their partners should consult their tax advisers as to the particular U.S. federal income tax consequences of owning and disposing of the ADSs or ordinary shares.

This discussion is based on the Internal Revenue Code of 1986, as amended (the “Code”), administrative pronouncements, judicial decisions, final, temporary and proposed Treasury regulations, and the U.S.-PRC income tax treaty ( the “Treaty”), all as of the date hereof, any of which is subject to change or differing interpretations, possibly with retroactive effect.

For purposes of this discussion, you are a “U.S. Holder” if you are eligible for the benefits of the Treaty and are a person that is, for U.S. federal income tax purposes, a beneficial owner of ADSs or ordinary shares and:

In general, if you own ADSs you will be treated as the owner of the underlying shares represented by those ADSs for U.S. federal income tax purposes. Accordingly, no gain or loss will be recognized if you exchange ADSs for the underlying shares represented by those ADSs.

Taxation of Distributions

The following discussion is subject to the discussion under “—Passive Foreign Investment Company Rules” below.

Distributions paid on ADSs or ordinary shares, other than certain pro rata distributions of ordinary shares, will generally be treated as dividends to the extent paid out of our current or accumulated earnings and profits (as determined under U.S. federal income tax principles). Because we do not maintain calculations of our earnings and profits under U.S. federal income tax principles, we expect that any distributions will be reported to you as dividends. Dividends will not be eligible for the dividends-received deduction generally available to U.S. corporations under the Code. Subject to applicable limitations and the discussion above regarding concerns expressed by the U.S. Treasury, dividends paid to certain non-corporate U.S. Holders may be taxable at a favorable rate. Dividends will be included in your income on the date of your, or in the case of ADSs, the depositary’s, receipt of the dividend. The amount of any dividend income paid in non-U.S. currency will be the U.S. dollar amount calculated by reference to the spot rate in effect on the date of actual or constructive receipt, regardless of whether the payment is in fact converted into U.S. dollars. If the dividend is converted into U.S. dollars on the date of receipt, you generally should not be required to recognize foreign currency gain or loss in respect of the dividend income. You may have foreign currency gain or loss if the dividend is converted into U.S. dollars after the date of receipt.

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Dividends will be treated as foreign-source income for foreign tax credit purposes. As described in “—PRC Taxation”, dividends paid by us may be subject to PRC withholding tax. For U.S. federal income tax purposes, the amount of the dividend income will include any amounts withheld in respect of PRC withholding tax. Subject to applicable limitations, which vary depending upon your circumstances, PRC taxes withheld from dividend payments (at a rate not exceeding the applicable Treaty rate) generally will be creditable against your U.S. federal income tax liability. The rules governing foreign tax credits are complex, and you should consult your tax advisers regarding the creditability of foreign taxes in your particular circumstances. In lieu of claiming a credit, you may elect to deduct PRC taxes in computing your taxable income, subject to applicable limitations. An election to deduct foreign taxes instead of claiming foreign tax credits applies to all foreign taxes paid or accrued in the taxable year.

Sale or Other Disposition of ADSs or Ordinary Shares

The following discussion is subject to the discussion under “—Passive Foreign Investment Company Rules” below.

Gain or loss realized on the sale or other taxable disposition of ADSs or ordinary shares will be capital gain or loss, and will be long-term capital gain or loss if you held the ADSs or ordinary shares for more than one year. The amount of the gain or loss will equal the difference between your tax basis in the ADSs or ordinary shares disposed of and the amount realized on the disposition, in each case as determined in U.S. dollars. This gain or loss will generally be U.S.-source gain or loss for foreign tax credit purposes. The deductibility of capital losses is subject to limitations.

As described in “—PRC Taxation,” gains on the sale of ADSs or ordinary shares may be subject to PRC taxes. You are entitled to use foreign tax credits to offset only the portion of your U.S. federal income tax liability that is attributable to foreign-source income. Because under the Code capital gains of U.S. persons are generally treated as U.S.-source income, this limitation may preclude you from claiming a credit for all or a portion of any PRC taxes imposed on any such gains. However, if you are eligible for the benefits of the Treaty, you may elect to treat the gain as PRC-source and therefore claim foreign tax credits in respect of PRC taxes on such disposition gains, subject to applicable limitations. You should consult your tax advisor regarding their eligibility for the benefits of the Treaty and the creditability of any PRC tax on disposition gains in your particular circumstances.

Passive Foreign Investment Company Rules

In general, a non-U.S. corporation will be a PFIC for any taxable year in which (i) 75% or more of its gross income consists of passive income or (ii) 50% or more of the value of its assets (generally determined on a quarterly average basis) consists of assets that produce, or are held for the production of, passive income (the “asset test”). For purposes of the above calculations, a non-U.S. corporation that directly or indirectly owns at least 25% by value of the shares of another corporation is treated as if it held its proportionate share of the assets of the other corporation and received directly its proportionate share of the income of the other corporation. Passive income generally includes interest, dividends, investment gains, and rents and royalties (other than certain rents or royalties derived in the active conduct of a trade or business). For these purposes, cash is a passive asset and the value of a non-U.S. corporation’s goodwill (which may be determined by reference to the excess of the sum of its market capitalization and liabilities over its booked assets) generally should be an active asset to the extent attributable to business activities that produce non-passive income.

Our assets other than goodwill are expected to consist primarily of cash and cash equivalents for the foreseeable future. Therefore, whether we will satisfy the asset test for the current or any future taxable year will depend largely on the quarterly value of our goodwill (which may be determined by reference to the market price of our ADSs or ordinary shares from time to time, which has been, and may continue to be volatile given the nature and early stage of our business). If our market capitalization declines while we continue to hold a significant amount of cash (including cash raised in this offering), the risk that we will be a PFIC will increase. Furthermore,

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because our gross income from sales is not yet significant, we could be a PFIC for any taxable year in which our interest and other investment income constitutes 75% or more of our total gross income. In addition, a company’s PFIC status is an annual determination that can be made only after the end of each taxable year. Based on our current market capitalization and our current and expected composition of income and assets, we do not expect to be a PFIC for our current taxable year. However, for the reasons described above we cannot give any assurance as to whether we will be a PFIC for the current or any future taxable year.

If we are a PFIC for any taxable year and any of our subsidiaries or other companies in which we own equity interests is also a PFIC (any such entity, a “Lower-tier PFIC”), you will be deemed to own a proportionate amount (by value) of the shares of each Lower-tier PFIC and generally will be subject to U.S. federal income tax according to the rules described in the subsequent paragraph on (i) certain distributions by a Lower-tier PFIC and (ii) dispositions of shares of Lower-tier PFICs, in each case as if you held your proportionate share of these shares directly, even though you will not receive the proceeds of those distributions or dispositions.

Generally, if we are a PFIC for any taxable year during which you hold ADSs or ordinary shares, gain recognized upon a disposition (including, under certain circumstances, a pledge) of ADSs or ordinary shares will be allocated ratably over your holding period for the ADSs or ordinary shares. The amounts allocated to the taxable year of disposition and to years before we became a PFIC will be taxed as ordinary income. The amount allocated to each other taxable year will be subject to tax at the highest rate in effect for that taxable year for individuals or corporations, as appropriate, and an interest charge will be imposed on the resulting tax liability for each relevant taxable year. Further, to the extent that distributions received by you on your ADSs or ordinary shares in a taxable year exceeds 125% of the average of the annual distributions on the ADSs or ordinary shares received during the preceding three taxable years or your holding period, whichever is shorter, these distributions will be subject to taxation in the same manner.

If we are a PFIC for any taxable year during which you own ADSs or ordinary shares, we will generally continue to be treated as a PFIC with respect to you for all succeeding years during which you own ADSs or ordinary shares, even if we cease to meet the threshold requirements for PFIC status. If we are a PFIC for any taxable year but cease to be PFIC for subsequent years, you should consult your tax adviser regarding the availability of a “deemed sale” election that would allow you to eliminate the continuing PFIC status under certain circumstances.

Alternatively, if we are a PFIC and if our ADSs or ordinary shares are “regularly traded” on a “qualified exchange,” you may be able to make a mark-to-market election that would result in tax treatment different from the general tax treatment described in the preceding paragraphs. Our ADSs or ordinary shares will be treated as “regularly traded” in any calendar year in which more than a de minimis quantity of the ADSs or ordinary shares, as the case may be, are traded on a qualified exchange on at least 15 days during each calendar quarter. The Nasdaq market on which the ADSs are listed is a qualified exchange for this purpose. If we are a PFIC and you make a mark-to-market election with respect to our ADSs or ordinary shares, you generally will recognize as ordinary income any excess of the fair market value of the relevant securities at the end of each taxable year over their adjusted tax basis, and will recognize an ordinary loss in respect of any excess of the adjusted tax basis of the relevant securities over their fair market value at the end of the taxable year (but only to the extent of the net amount of income previously included as a result of the mark-to-market election). If you make the election, your tax basis in the relevant securities will be adjusted to reflect these income or loss amounts. Any gain recognized on the sale or other disposition of relevant securities in a year in which we are a PFIC will be treated as ordinary income and any loss will be treated as an ordinary loss (but only to the extent of the net amount of income previously included as a result of the mark-to-market election). There is no provision under the Code, Treasury regulations or administrative guidance that would permit you to make a mark-to-market election with respect to Lower-tier PFICs, if any, the shares of which are not regularly traded.

You may be subject to alternative treatment if we are a PFIC for any taxable year and we provide the information necessary to make a qualified electing fund (“QEF”) election. If we determine at our discretion that we were a PFIC for any taxable year, we intend to provide to you, following your request, the information necessary for you to make a QEF election with respect to us. In that event, we will endeavor to cause each Lower-tier PFIC that we

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control to provide the relevant information with respect to that Lower-tier PFIC. However, there can be no assurance that we will be able to cause any Lower-tier PFIC we do not control to provide such information. We may elect to provide the information necessary to make the QEF election on our website. You must make the QEF Election for the first taxable year that we are treated as a PFIC by attaching a separate properly completed IRS Form 8621 for each PFIC to your timely filed U.S. federal income tax return for that year. If we determine that we are a PFIC for any taxable year and you make a timely QEF Election with respect to us, your tax treatment will be different from the PFIC consequences described above. You will be taxable on a current basis on your pro rata share of our ordinary earnings and net capital gain (at ordinary income and capital gain rates, respectively) for each taxable year that we are a PFIC. If you make a QEF Election with respect to us, any distributions paid by us out of our earnings and profits that were previously included in your income under the QEF Election will not be taxable to you. You will increase your tax basis in your ADSs or ordinary shares by an amount equal to any income included under the QEF Election and will decrease your tax basis by any amount distributed on the ADSs or ordinary shares that is not included in your income. In addition, you will recognize capital gain or loss on the disposition of ADSs or ordinary shares in an amount equal to the difference between the amount realized and your adjusted tax basis in the ADSs or ordinary shares, as determined in U.S. dollars. If you make QEF Elections with respect to us and Lower-tier PFICs, if any, you may be required to pay U.S. federal income tax with respect to your ADSs or ordinary shares for any taxable year significantly in excess of any cash distributions received on the ADSs or ordinary shares for such taxable year. You should consult your tax advisor regarding making QEF Elections in your particular circumstances.

If you own ADSs or ordinary shares during any year in which we are a PFIC, you generally will be required to file annual reports on IRS Form 8621 (or any successor form) with respect to us, generally with your federal income tax return for that year. Additionally, if we are a PFIC for the taxable year in which we paid a dividend or the prior taxable year, the reduced rates discussed above with respect to dividends paid to certain non-corporate U.S. Holders will not apply. You should consult your tax adviser regarding the determination of whether we are a PFIC for any taxable year and the potential application of the PFIC rules.

Information Reporting and Backup Withholding

Payments of dividends and sales proceeds that are made within the United States or through certain U.S.-related financial intermediaries may be subject to information reporting and backup withholding, unless (i) you are a corporation or other exempt recipient or (ii) in the case of backup withholding, you provide a correct taxpayer identification number and certify that you are not subject to backup withholding. The amount of any backup withholding from a payment to you will be allowed as a credit against your U.S. federal income tax liability and may entitle it to a refund, provided that the required information is timely furnished to the Internal Revenue Service.

THE ABOVE DISCUSSION DOES NOT COVER ALL TAX MATTERS THAT MAY BE OF IMPORTANCE TO YOU. YOU ARE STRONGLY URGED TO CONSULT YOUR OWN TAX ADVISER ABOUT THE TAX CONSEQUENCES OF AN INVESTMENT IN THE ADSs.

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Legal matters

We are being represented by Davis Polk & Wardwell LLP with respect to legal matters of United States federal securities and New York State law. The underwriters are being represented by Simpson Thacher & Bartlett LLP with respect to certain legal matters as to United States federal securities and New York State law. The validity of the ordinary shares represented by the ADSs offered in this offering and legal matters as to Cayman Islands law will be passed upon for us by Travers Thorp Alberga. Certain legal matters as to PRC law will be passed upon for us by Zhong Lun Law Firm and for the underwriters by Commerce & Finance Law Offices. Davis Polk & Wardwell LLP may rely upon Travers Thorp Alberga with respect to matters governed by Cayman Islands law and Zhong Lun Law Firm with respect to matters governed by PRC law. Simpson Thacher & Bartlett LLP may rely upon Commerce & Finance Law Offices with respect to matters governed by PRC law.

Experts

The consolidated financial statements incorporated in this prospectus by reference from our annual report for the fiscal year ended December 31, 2020 on Form 10-K filed with the SEC on March 1, 2021, have been audited by Deloitte Touche Tohmatsu Certified Public Accountants LLP, an independent registered public accounting firm, as stated in their report, which is incorporated by reference herein. Such consolidated financial statements have been so incorporated in reliance upon the report of such firm given upon their authority as experts in accounting and auditing.

The office of Deloitte Touche Tohmatsu Certified Public Accountants LLP is located at 30/F Bund Center, 222 East Yan An Road, Shanghai 200002, People’s Republic of China.

Where you can find more information

We are subject to the reporting requirements of the Securities Exchange Act of 1934, as amended, or the Exchange Act, that are applicable to a domestic issuer. We file reports, including annual reports on Form 10-K, and other information with the SEC pursuant to the rules and regulations of the SEC that apply to domestic issuers. Documents that we file with the SEC are also available on the website maintained by the SEC (www.sec.gov). Those filings are also available to the public on, or accessible through, our website at www.zailaboratory.com. The information contained on or accessible through our corporate website or any other website that we may maintain is not incorporated by reference herein and is not part of this prospectus supplement and the accompanying prospectus or the registration statement of which this prospectus supplement and the accompanying prospectus are a part.

This prospectus supplement and the accompanying prospectus are part of the registration statement and do not contain all the information in the registration statement. Whenever a reference is made in this prospectus supplement to a contract or other document of Zai Lab Limited, the reference is only a summary, and you should refer to the exhibits that are a part of the registration statement for a copy of the contract or other document. You may review a copy of the registration statement through the SEC’s website.

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Incorporation of documents by reference

The SEC allows us to incorporate by reference the information we file with them. This means that we can disclose important information to you by referring to documents. The information that we incorporate by reference is an important part of this prospectus supplement. We incorporate by reference the following documents and any future filings that we make with the SEC under Sections 13(a), 13(c) and 15(d) of the Securities Exchange Act of 1934, as amended, until we complete this offering using this prospectus supplement:

Information that we file with the SEC will automatically update and supersede the information included in this prospectus supplement or previously incorporated by reference into this prospectus supplement. All information appearing in this prospectus supplement is qualified in its entirety by the information and financial statements, including the notes, contained in the documents that we incorporate by reference in this prospectus supplement.

You may request a copy of these filings, at no cost, by writing or telephoning us at the following address:

Zai Lab Limited

4560 Jinke Road

Bldg. 1, Fourth Floor

Pudong

Shanghai, China 201210

+86 21 6163 2588

You should rely only on the information that we incorporate by reference or provide in this prospectus supplement or the accompanying prospectus. We have not authorized anyone to provide you with different information. You should not assume that the information in this prospectus supplement or the accompanying prospectus is accurate as of any date other than the date on the front of those documents.

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PROSPECTUS

ZAI LAB LIMITED

             Ordinary Shares

in the form of ordinary shares or American depositary shares

Zai Lab Limited may use this prospectus to offer from time to time ordinary shares, directly or in the form of American depositary shares. Zai Lab Limited’s American depositary shares, or ADSs, each representing one ordinary share, are listed on NASDAQ Global Market under the symbol “ZLAB.” Zai Lab Limited’s ordinary shares are listed on The Stock Exchange of Hong Kong Limited under the stock code “9688.”

In addition, from time to time, any selling shareholders named in a prospectus supplement may offer and sell our ordinary shares, including ordinary shares represented by ADSs, held by them. We will not receive any proceeds from the sale of shares of our ordinary shares by the selling shareholders.

We will provide the specific terms of any offering in a supplement to this prospectus. Any prospectus supplement may also add, update or change information contained in this prospectus. You should carefully read this prospectus and the applicable prospectus supplement as well as the documents incorporated by reference in this prospectus before you purchase any of the securities offered hereby.

The ordinary shares may be offered and sold in the same offering or in separate offerings; to or through underwriters, dealers and agents; or directly to purchasers. The names of any underwriters, dealers or agents involved in the sale of our ordinary shares, their compensation and any over-allotment options held by them will be described in the applicable prospectus supplement. See “Plan of Distribution.”

The addresses and telephone numbers of our principal executive offices are set forth on page 4.

Investing in these securities involves certain risks. See “Risk Factors” beginning on page 5.

Neither the Securities and Exchange Commission nor any other regulatory body has approved or disapproved of these securities, or passed upon the accuracy or adequacy of this prospectus. Any representation to the contrary is a criminal offense.

This prospectus may not be used to sell securities unless it is accompanied by a prospectus supplement.

Prospectus dated April 19, 2021.

TABLE OF CONTENTS

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ABOUT THIS PROSPECTUS

This prospectus is part of a registration statement that we filed with the Securities and Exchange Commission, or SEC, utilizing a shelf registration process. Under this shelf process, we may sell any combination of the securities described in this prospectus in one or more offerings. This prospectus provides you with a general description of the securities we may offer. Each time we sell securities, we will provide a prospectus supplement that will contain specific information about the terms of those securities and their offering, including the specific amounts, prices and terms of the offered securities. The prospectus supplement may also add, update or change information contained in this prospectus. You should read both this prospectus and any prospectus supplement together with the additional information described under the headings “Where You Can Find More Information” and “Incorporation of Documents by Reference.”

If you are in a jurisdiction where offers to sell, or solicitations of offers to purchase, the securities offered by this document are unlawful, or if you are a person to whom it is unlawful to direct these types of activities, then the offer presented in this document does not extend to you.

You should assume that the information in this prospectus or any prospectus supplement, as well as the information incorporated by reference in this prospectus or any prospectus supplement, is accurate only as of the date of the documents containing the information, unless the information specifically indicates that another date applies. Our business, financial condition, results of operations and prospects may have changed since those dates.

Wherever references are made in this prospectus to information that will be included in a prospectus supplement, to the extent permitted by applicable law, rules or regulations, we may instead include such information or add, update or change the information contained in this prospectus by means of a post-effective amendment to the registration statement of which this prospectus is a part, through filings we make with the SEC that are incorporated by reference in this prospectus or by any other method as may then be permitted under applicable law, rules or regulations.

In this prospectus, the terms “we,” “our” and “us” refer to Zai Lab Limited. Zai Lab Limited will be the issuer in an offering of ordinary shares. The ordinary shares, including ordinary shares in the form of ADSs, that may be offered using this prospectus are referred to collectively as the securities. Additionally, the term “Greater China” refers to mainland China, Hong Kong, Taiwan, and Macau.

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CAUTIONARY STATEMENT CONCERNING FORWARD-LOOKING STATEMENTS

This prospectus and the documents incorporated herein by reference contain forward-looking statements. Forward-looking statements are neither historical facts nor assurances of future performance. Instead, they are based on our current beliefs, expectations and assumptions regarding the future of our business, future plans and strategies, our operational results and other future conditions. Forward-looking statements can be identified by words such as “aim,” “anticipate,” “believe,” “estimate,” “expect,” “intend,” “may,” “plan,” “predict,” “project,” “seek,” “target,” “potential,” “will,” “would,” “could,” “should,” “continue,” “contemplate” and other similar expressions, although not all forward-looking statements contain these identifying words. These forward-looking statements include all matters that are not historical facts. They appear in a number of places throughout this prospectus and the documents incorporated herein by reference and include statements regarding our intentions, beliefs or current expectations concerning, among other things, our results of operations, financial condition, liquidity, prospects, growth, strategies and the industry in which we operate.

By their nature, forward-looking statements involve risks and uncertainties because they relate to events and depend on circumstances that may or may not occur in the future. We believe that these risks and uncertainties include, but are not limited to, those described in the “Risk Factors” section of this prospectus and the documents incorporated herein by reference, which include, but are not limited to, the following:

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These factors should not be construed as exhaustive and should be read with the other cautionary statements in this prospectus and the documents incorporated herein by reference.

Although we base these forward-looking statements on assumptions that we believe are reasonable when made, we caution you that forward-looking statements are not guarantees of future performance and that our actual results of operations, financial condition and liquidity, and the development of the industry in which we operate may differ materially from those made in or suggested by the forward-looking statements contained in this prospectus and the documents incorporated herein by reference. In addition, even if our results of operations, financial condition and liquidity, and the development of the industry in which we operate, are consistent with the forward-looking statements contained in this prospectus and the documents incorporated herein by reference, those results or developments may not be indicative of results or developments in subsequent periods.

Given these risks and uncertainties, you are cautioned not to place undue reliance on these forward-looking statements. Any forward-looking statement that we make in this prospectus and the documents incorporated herein by reference speaks only as of the date of such statement. Comparisons of results for current and any prior periods are not intended to express any future trends or indications of future performance, unless specifically expressed as such, and should only be viewed as historical data.

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OUR COMPANY

We are an innovative, research-based, commercial stage biopharmaceutical company with a substantial presence in both Greater China and the United States. We are focused on developing and commercializing therapies that address medical conditions with unmet needs in oncology, autoimmune disorders and infectious disease. Our aim is to become a leading global biopharmaceutical company discovering, developing and commercializing products to extend and improve the lives of patients worldwide. Since 2014, we have taken steps to execute our strategy to become a fully-integrated global biopharmaceutical company with substantial research and development, business development and commercialization capabilities.

Our company was founded in the Cayman Islands on March 28, 2013 as an exempted company with limited liability under the Companies Act (Revised) (the “Companies Act”) of the Cayman Islands. Our principal executive offices are located at 4560 Jinke Road, Bldg. 1, Fourth Floor, Pudong, Shanghai, China 201210. Our telephone number at that address is +86 21 6163 2588. The address of our registered office in the Cayman Islands is Harbour Place 2nd Floor, 103 South Church Street, P.O. Box 472, George Town, Grand Cayman KY1-1106, Cayman Islands. Our agent for service of process in the United States is Cogency Global Inc., located at 122 East 42nd Street, 18th Floor, New York, NY 10168.

For more information about us, see our most recent annual report on Form 10-K.

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RISK FACTORS

Investing in the securities offered using this prospectus involves risk. Before you decide to buy our securities, you should carefully consider the risks described under the heading “Risk Factors” in our most recent annual report for the year ended December 31, 2020 on Form 10-K, which is incorporated herein by reference, as well as the risks that are described in the applicable prospectus supplement and in other documents incorporated by reference into this prospectus. If any of these risks actually occur, our business, financial condition and results of operations could suffer, and the trading price and liquidity of the securities offered using this prospectus could decline, in which case you may lose all or part of your investment.

Please see “Where You Can Find More Information” and “Incorporation of Documents by Reference” for information on where you can find the documents we have filed with or furnished to the SEC and which are incorporated into this prospectus by reference.

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ENFORCEABILITY OF CERTAIN CIVIL LIABILITIES

We are incorporated in the Cayman Islands to take advantage of certain benefits associated with being a Cayman Islands exempted company, such as:

However, certain disadvantages accompany incorporation in the Cayman Islands. These disadvantages include, but are not limited to:

Our constituent documents do not contain provisions requiring that disputes, including those arising under the securities laws of the United States, between us, our officers, directors and shareholders, be arbitrated.

All of our commercial operations are conducted in China, and substantially all of our assets are located in China. Some of our directors and executive officers are nationals or residents of jurisdictions other than the United States and most of their assets are located outside the United States. As a result, it may be difficult for a shareholder to effect service of process within the United States upon these persons, or to enforce against us or them judgments obtained in United States courts, including judgments predicated upon the civil liability provisions of the securities laws of the United States or any state in the United States.

We have appointed Cogency Global Inc., located at 122 East 42nd Street, 18th Floor, New York, NY 10168 as our agent upon whom process may be served in any action brought against us under the securities laws of the United States.

Travers Thorp Alberga, our legal counsel as to Cayman Islands law has advised us that there is uncertainty as to whether the courts of the Cayman Islands, and there is also uncertainty as to whether the courts of the China, would:

There is uncertainty with regard to Cayman Islands law relating to whether a judgment obtained from the United States courts under civil liability provisions of the securities laws will be determined by the courts of the Cayman Islands as penal or punitive in nature. If such a determination is made, the courts of the Cayman Islands will not recognize or enforce the judgment against a Cayman Islands company. Because the courts of the Cayman Islands have yet to rule on whether such judgments are penal or punitive in nature, it is uncertain whether they would be enforceable in the Cayman Islands. Travers Thorp Alberga has advised us that although there is no statutory enforcement in the Cayman Islands of judgments obtained in the federal or state courts of the United States, a

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judgment in personam obtained in such jurisdiction will be recognized and enforced in the courts of the Cayman Islands at common law, without any re-examination of the merits of the underlying dispute, by an action commenced on the foreign judgment debt in the Grand Court of the Cayman Islands, provided such judgment:

The recognition and enforcement of foreign judgments are provided for under the PRC Civil Procedures Law. PRC courts may recognize and enforce foreign judgments in accordance with the requirements of the PRC Civil Procedures Law based either on treaties between China and the country where the judgment is made or on principles of reciprocity between jurisdictions. China does not have any treaties or other form of reciprocity with the United States or the Cayman Islands that provide for the reciprocal recognition and enforcement of foreign judgments. In addition, according to the PRC Civil Procedures Law, courts in China will not enforce a foreign judgment against us or our directors and officers if they decide that the judgment violates the basic principles of PRC law or national sovereignty, security or social public interest. As a result, it is uncertain whether and on what basis a PRC court would enforce a judgment rendered by a court in the United States or in the Cayman Islands. Under the PRC Civil Procedures Law, foreign shareholders may originate actions based on PRC law against a company in China for disputes if they can establish sufficient nexus to the PRC for a PRC court to have jurisdiction, and meet other procedural requirements, including, among others, the plaintiff must have a direct interest in the case, and there must be a concrete claim, a factual basis and a cause for the suit. However, it would be difficult for foreign shareholders to establish sufficient nexus to China by virtue only of holding our ADSs or ordinary shares.

In addition, it will be difficult for U.S. shareholders to originate actions against us in China in accordance with PRC laws because we are incorporated under the laws of the Cayman Islands and it will be difficult for U.S. shareholders, by virtue only of holding our ADSs or ordinary shares, to establish a connection to China for a PRC court to have jurisdiction as required under the PRC Civil Procedures Law.

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USE OF PROCEEDS

We intend to use the net proceeds from the sale of the securities offered by us for general corporate purposes, unless otherwise set forth in the applicable prospectus supplement.

We will not receive any proceeds from the sale of shares of our ordinary shares by the selling shareholders.

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DESCRIPTION OF SHARE CAPITAL

We are a Cayman Islands company, and our affairs are governed by our Fifth Amended and Restated Memorandum of Association, the Fourth Amended and Restated Articles of Association and the Companies Act.

Our authorized share capital consists of US$30,000.00 divided into 500,000,000 shares of a nominal or par value of US$0.00006 each. As of April 16, 2021, we had 89,192,343 ordinary shares outstanding.

The following are summaries of material provisions of our Fourth Amended and Restated Articles of Association, which became effective immediately prior to the completion of our initial public offering in September 2017, as amended by our Fifth Amended and Restated Memorandum of Association, which became effective in September 2020, insofar as they relate to the material terms of our ordinary shares.

Ordinary Shares

General. Our ordinary shares are issued in registered form, and are issued when registered in our register of members. Certificates representing the ordinary shares are issued in registered form.

Dividends. The holders of our ordinary shares are entitled to such dividends as may be declared by our board of directors. Our Fourth Amended and Restated Articles of Association provides that dividends may be declared and paid out of our profits, realized or unrealized, or from any reserve set aside from profits which our board of directors determine is no longer needed. Dividends may also be declared and paid out of share premium account or any other fund or account which can be authorized for this purpose in accordance with the Companies Act. Holders of ordinary shares will be entitled to the same amount of dividends, if declared.

Voting rights. In respect of all matters subject to a shareholders’ vote, each ordinary share is entitled to one vote. Voting at any meeting of shareholders is by show of hands unless a poll is demanded. A poll may be demanded by the chairman of such meeting or any one or more shareholders present in person or by proxy and who together hold not less than 10% of the nominal value of the total issued voting shares of our company. Each holder of our ordinary shares is entitled to have one vote for each ordinary share registered in his or her name on our register of members.

A quorum required for a meeting of shareholders consists of one or more shareholders who hold at least one-third of all voting power of our share capital in issue at the date of the meeting present in person or by proxy or, if a corporation or other non-natural person, by its duly authorized representative. Shareholders’ meetings may be held annually. Each general meeting, other than an annual general meeting, shall be an extraordinary general meeting. Extraordinary general meetings may be called by a majority of our board of directors or our chairman or upon a requisition of shareholders holding at the date of deposit of the requisition not less than one-third of the aggregate voting power of our company. Advance notice of at least seven days is required for the convening of our annual general meeting and other general meetings unless such notice is waived in accordance with our articles of association.

An ordinary resolution to be passed at a meeting by the shareholders requires the affirmative vote of a simple majority of the votes attaching to all issued and outstanding shares cast at a meeting, while a special resolution also requires the affirmative vote of no less than two-thirds of the votes cast attaching to the issued and outstanding shares at a meeting. A special resolution will be required for important matters such as a change of name or making changes to our Fourth Amended and Restated Articles of Association.

Transfer of ordinary shares. Subject to the restrictions set out below, any of our shareholders may transfer all or any of his or her ordinary shares by an instrument of transfer in the usual or common form or any other form approved by our board of directors.

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Our board of directors may, in its absolute discretion, decline to register any transfer of any ordinary share which is not fully paid up or on which we have a lien. Our board of directors may also decline to register any transfer of any ordinary share unless:

If our directors refuse to register a transfer, they shall, within two months after the date on which the instrument of transfer was lodged, send to each of the transferor and the transferee notice of such refusal.

The registration of transfers may, on 14 days’ notice being given by advertisement in one or more newspapers or by electronic means, be suspended and the register closed at such times and for such periods as our board of directors may from time to time determine, provided, however, that the registration of transfers shall not be suspended nor the register closed for more than 30 days in any year.

Liquidation. On a return of capital on winding up or otherwise (other than on conversion, redemption or purchase of ordinary shares), assets available for distribution among the holders of ordinary shares shall be distributed by a liquidator who may divide our assets for distribution among our shareholders in his discretion. The liquidator also may vest all or part of our assets in trust. None of our shareholders may be compelled to accept any shares subject to liability.

Calls on ordinary shares and forfeiture of ordinary shares. Our board of directors may from time to time make calls upon shareholders for any amounts unpaid on their ordinary shares in a notice served to such shareholders at least 14 clear days prior to the specified time of payment. The ordinary shares that have been called upon and remain unpaid are subject to forfeiture.

Redemption of ordinary shares. The Companies Act and Fourth Amended and Restated Articles of Association permit us to purchase our own shares. In accordance with our Fourth Amended and Restated Articles of Association and provided the necessary shareholders or board approval have been obtained, we may issue shares on terms that are subject to redemption, at our option or at the option of the holders of these shares, on such terms and in such manner, including out of capital, as may be determined by our board of directors.

Variations of rights of shares. All or any of the special rights attached to any class of shares may, subject to the provisions of the Companies Act, be varied with the written consent of the holders of a majority of the issued shares of that class or with the sanction of a special resolution passed at a general meeting of the holders of the shares of that class. The rights conferred upon the holders of the shares of any class issued shall not, unless otherwise expressly provided by the terms of issue of the shares of that class, be deemed to be varied by the creation or issue of further shares ranking pari passu with such existing class of shares. Holders of our ordinary shares do not have preemptive, subscription or conversion rights. The ordinary shares are not subject to further calls or assessment by us. There are no sinking fund provisions applicable to the ordinary shares.

Inspection of books and records. Holders of our ordinary shares have no general right under Cayman Islands law to inspect or obtain copies of our list of shareholders or our corporate records. However, we will file annual audited financial statements with the SEC. See “Incorporation of Documents by Reference.”

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Issuance of additional shares. Our Fourth Amended and Restated Articles of Association authorizes our board of directors to issue additional ordinary shares from time to time as our board of directors shall determine, to the extent of available authorized but unissued shares.

Our Fourth Amended and Restated Articles of Association also authorizes our board of directors to establish from time to time one or more series of preferred shares and to determine, with respect to any series of preferred shares, the terms and rights of that series, including:

Our board of directors may issue preferred shares without action by our shareholders to the extent authorized but unissued. Issuance of these shares may dilute the voting power of holders of ordinary shares.

Anti-takeover provisions. Some provisions of our Fourth Amended and Restated Articles of Association may discourage, delay or prevent a change of control of our company or management that shareholders may consider favorable, including provisions that authorize our board of directors to issue preferred shares in one or more series and to designate the price, rights, preferences, privileges and restrictions of such preferred shares without any further vote or action by our shareholders.

Exempted company. We are an exempted company with limited liability under the Companies Act. The Companies Act distinguishes between ordinary resident companies and exempted companies. Any company that is registered in the Cayman Islands but conducts business mainly outside of the Cayman Islands may apply to be registered as an exempted company. The requirements for an exempted company are essentially the same as for an ordinary company except that an exempted company:

“Limited liability” means that the liability of each shareholder is limited to the amount unpaid by the shareholder on the shares of the company.

Differences in corporate law

The Companies Act is modeled after that of English law but does not follow many recent English law statutory enactments. In addition, the Companies Act differs from laws applicable to United States corporations and their shareholders. Set forth below is a summary of the significant differences between the provisions of the Companies Act applicable to us and the laws applicable to companies incorporated in the State of Delaware.

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Mergers and similar arrangements. A merger of two or more constituent companies under Cayman Islands law requires a plan of merger or consolidation to be approved by the directors of each constituent company and authorization by (i) a special resolution of the shareholders and (ii) such other authorization, if any, as may be specified in such constituent company’s articles of association.

A merger between a Cayman parent company and its Cayman subsidiary or subsidiaries does not require authorization by a resolution of shareholders of that Cayman subsidiary if a copy of the plan of merger is given to every member of that Cayman subsidiary to be merged unless that member agrees otherwise. For this purpose, a subsidiary is a company of which at least 90% of the issued shares entitled to vote are owned by the parent company.

The consent of each holder of a fixed or floating security interest over a constituent company is required unless this requirement is waived by a court in the Cayman Islands.

Save in certain circumstances, a dissentient shareholder of a Cayman constituent company is entitled to payment of the fair value of his shares upon dissenting to a merger or consolidation. The exercise of appraisal rights will preclude the exercise of any other rights save for the right to seek relief on the grounds that the merger or consolidation is void or unlawful.

In addition, there are statutory provisions that facilitate the reconstruction and amalgamation of companies, provided that the arrangement is approved by a majority in number of each class of shareholders and creditors with whom the arrangement is to be made, and who must in addition represent three-fourths in value of each such class of shareholders or creditors, as the case may be, that are present and voting either in person or by proxy at a meeting, or meetings, convened for that purpose. The convening of the meetings and subsequently the arrangement must be sanctioned by the Grand Court of the Cayman Islands. While a dissenting shareholder has the right to express to the court the view that the transaction ought not to be approved, the court can be expected to approve the arrangement if it determines that:

When a takeover offer is made and accepted by holders of 90% of the shares within four months, the offeror may, within a two-month period commencing on the expiration of such four month period, require the holders of the remaining shares to transfer such shares on the terms of the offer. An objection can be made to the Grand Court of the Cayman Islands but this is unlikely to succeed in the case of an offer which has been so approved unless there is evidence of fraud, bad faith or collusion.

If an arrangement and reconstruction is thus approved, the dissenting shareholder would have no rights comparable to appraisal rights, which would otherwise ordinarily be available to dissenting shareholders of Delaware corporations, providing rights to receive payment in cash for the judicially determined value of the shares.

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Shareholders’ suits. In principle, we will normally be the proper plaintiff and as a general rule a derivative action may not be brought by a minority shareholder. However, based on English authorities, which would in all likelihood be of persuasive authority in the Cayman Islands, there are exceptions to the foregoing principle, including when:

Indemnification of directors and executive officers and limitation of liability. Cayman Islands law does not limit the extent to which a company’s memorandum and articles of association may provide for indemnification of officers and directors, except to the extent any such provision may be held by the Cayman Islands courts to be contrary to public policy, such as to provide indemnification against civil fraud or the consequences of committing a crime. Our Fourth Amended and Restated Articles of Association permit indemnification of officers and directors for losses, damages, costs and expenses incurred in their capacities as such unless such losses or damages arise from dishonesty or fraud of such directors or officers. This standard of conduct is generally the same as permitted under the Delaware General Corporation Law for a Delaware corporation. In addition, we intend to enter into indemnification agreements with our directors and executive officers that provide such persons with additional indemnification beyond that provided in our Fourth Amended and Restated Articles of Association.

Insofar as indemnification for liabilities arising under the Securities Act may be permitted to our directors, officers or persons controlling us under the foregoing provisions, we have been informed that in the opinion of the SEC, such indemnification is against public policy as expressed in the Securities Act and is therefore unenforceable.

Directors’ fiduciary duties. Under Delaware corporate law, a director of a Delaware corporation has a fiduciary duty to the corporation and its shareholders. This duty has two components: the duty of care and the duty of loyalty. The duty of care requires that a director act in good faith, with the care that an ordinarily prudent person would exercise under similar circumstances. Under this duty, a director must inform himself of, and disclose to shareholders, all material information reasonably available regarding a significant transaction. The duty of loyalty requires that a director acts in a manner he reasonably believes to be in the best interests of the corporation. He must not use his corporate position for personal gain or advantage. This duty prohibits self-dealing by a director and mandates that the best interest of the corporation and its shareholders take precedence over any interest possessed by a director, officer or controlling shareholder and not shared by the shareholders generally. In general, actions of a director are presumed to have been made on an informed basis, in good faith and in the honest belief that the action taken was in the best interests of the corporation. However, this presumption may be rebutted by evidence of a breach of one of the fiduciary duties. Should such evidence be presented concerning a transaction by a director, the director must prove the procedural fairness of the transaction, and that the transaction was of fair value to the corporation.

As a matter of Cayman Islands law, a director of a Cayman Islands company is in the position of a fiduciary with respect to the company and therefore it is considered that he or she owes the following duties to the company—a duty to act bona fide in the best interests of the company, a duty not to make a profit based on his or her position as director (unless the company permits him or her to do so) and a duty not to put himself or herself in a position where the interests of the company conflict with his or her personal interest or his or her duty to a third party. A director of a Cayman Islands company owes to the company a duty to act with skill and care. It was previously considered that a director need not exhibit in the performance of his or her duties a greater degree of skill than may reasonably be expected from a person of his or her knowledge and experience. However, English and Commonwealth courts have moved towards an objective standard with regard to the required skill and care and these authorities are likely to be followed in the Cayman Islands.

Shareholder action by written consent. Under the Delaware General Corporation Law, a corporation may eliminate the right of shareholders to act by written consent by amendment to its certificate of incorporation.

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Cayman Islands law and our Fourth Amended and Restated Articles of Association provide that shareholders may approve corporate matters by way of a unanimous written resolution signed by or on behalf of each shareholder who would have been entitled to vote on such matter at a general meeting without a meeting being held.

Shareholder proposals. Under the Delaware General Corporation Law, a shareholder has the right to put any proposal before the annual meeting of shareholders, provided it complies with the notice provisions in the governing documents. A special meeting may be called by the board of directors or any other person authorized to do so in the governing documents, but shareholders may be precluded from calling special meetings.

Cayman Islands law does not provide shareholders any right to put proposal before a meeting or requisition a general meeting. However, these rights may be provided in articles of association. Our Fourth Amended and Restated Articles of Association allow our shareholders holding not less than one-third of all voting power of our share capital in issue to requisition a shareholders’ meeting. Other than this right to requisition a shareholders’ meeting, our Fourth Amended and Restated Articles of Association do not provide our shareholders other right to put proposal before a meeting. As an exempted Cayman Islands company, we are not obliged by law to call shareholders’ annual general meetings.

Cumulative voting. Under the Delaware General Corporation Law, cumulative voting for elections of directors is not permitted unless the corporation’s certificate of incorporation specifically provides for it. Cumulative voting potentially facilitates the representation of minority shareholders on a board of directors since it permits the minority shareholder to cast all the votes to which the shareholder is entitled on a single director, which increases the shareholders’ voting power with respect to electing such director. There are no prohibitions in relation to cumulative voting under the laws of the Cayman Islands but our Fourth Amended and Restated Articles of Association do not provide for cumulative voting. As a result, our shareholders are not afforded any less protections or rights on this issue than shareholders of a Delaware corporation.

Removal of directors. Under the Delaware General Corporation Law, a director of a corporation with a classified board may be removed only for cause with the approval of a majority of the outstanding shares entitled to vote, unless the certificate of incorporation provides otherwise. Under our Fourth Amended and Restated Articles of Association, directors may be removed with or without cause, by an ordinary resolution of our shareholders.

Transactions with interested shareholders. The Delaware General Corporation Law contains a business combination statute applicable to Delaware corporations whereby, unless the corporation has specifically elected not to be governed by such statute by amendment to its certificate of incorporation, it is prohibited from engaging in certain business combinations with an “interested shareholder” for three years following the date that such person becomes an interested shareholder. An interested shareholder generally is a person or a group who or which owns or owned 15% or more of the target’s outstanding voting share within the past three years. This has the effect of limiting the ability of a potential acquirer to make a two-tiered bid for the target in which all shareholders would not be treated equally. The statute does not apply if, among other things, prior to the date on which such shareholder becomes an interested shareholder, the board of directors approves either the business combination or the transaction which resulted in the person becoming an interested shareholder. This encourages any potential acquirer of a Delaware corporation to negotiate the terms of any acquisition transaction with the target’s board of directors.

Cayman Islands law has no comparable statute. As a result, we cannot avail ourselves of the types of protections afforded by the Delaware business combination statute. However, although Cayman Islands law does not regulate transactions between a company and its significant shareholders, it does provide that such transactions must be entered into bona fide in the best interests of the company and not with the effect of constituting a fraud on the minority shareholders.

Dissolution; winding up. Under the Delaware General Corporation Law, unless the board of directors approves the proposal to dissolve, dissolution must be approved by shareholders holding 100% of the total voting power of

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the corporation. Only if the dissolution is initiated by the board of directors may it be approved by a simple majority of the corporation’s outstanding shares. Delaware law allows a Delaware corporation to include in its certificate of incorporation a supermajority voting requirement in connection with dissolutions initiated by the board. Under Cayman Islands law, a company may be wound up by either an order of the courts of the Cayman Islands or by a special resolution of its members or, if the company is unable to pay its debts as they fall due, by an ordinary resolution of its members. The court has authority to order winding up in a number of specified circumstances including where it is, in the opinion of the court, just and equitable to do so. Under the Companies Act and Fourth Amended and Restated Articles of Association, our company may be dissolved, liquidated or wound up by a special resolution of our shareholders.

Variation of rights of shares. Under the Delaware General Corporation Law, a corporation may vary the rights of a class of shares with the approval of a majority of the outstanding shares of such class, unless the certificate of incorporation provides otherwise. Under Cayman Islands law and our Fourth Amended and Restated Articles of Association, if our share capital is divided into more than one class of shares, we may vary the rights attached to any class with the written consent of the holders of a majority of the issued shares of that class or with the sanction of a special resolution passed at a general meeting of the holders of the shares of that class.

Amendment of governing documents. Under the Delaware General Corporation Law, a corporation’s governing documents may be amended with the approval of a majority of the outstanding shares entitled to vote, unless the certificate of incorporation provides otherwise. As permitted by Cayman Islands law, our Fourth Amended and Restated Articles of Association may only be amended with a special resolution of our shareholders.

Rights of non-resident or foreign shareholders. There are no limitations imposed by our fourth memorandum and articles of association on the rights of non-resident or foreign shareholders to hold or exercise voting rights on our shares. In addition, there are no provisions in our Fourth Amended and Restated Articles of Association governing the ownership threshold above which shareholder ownership must be disclosed.

Registration rights

In connection with our issuance of Series C preferred shares, we and all of our then shareholders entered into a third amended and restated shareholders agreement in June 2017, or the Shareholders Agreement.

Pursuant to our shareholders’ agreement, we have granted certain registration rights to our shareholders. Such registration rights would terminate with respect to a shareholder upon the earlier of (i) the date of a deemed liquidation event, (ii) five years following the consummation of our IPO in September 2017 and (iii) such time at which all registrable securities held by a shareholder proposed to be sold may be sold under Rule 144 of the Securities Act in any 90-day period without registration in compliance with Rule 144 of the Securities Act. Set forth below is a description of the registration rights granted under the agreement.

Demand registration rights. Upon a written request from the holders of at least 10% of (a) the voting power of the registrable securities, (b) the then outstanding Series B preferred shares and any ordinary shares converted from Series B shares together or (c) the then outstanding Series C preferred shares and any ordinary shares converted from Series C preferred shares together, we must file a registration statement covering the offer and sale of the registrable securities held by the requesting shareholders and other holders who choose to participate in the offering in the event that the anticipated gross receipts from this offering are to exceed $10,000,000. Registrable securities include, among others, our ordinary shares issued or to be issued upon conversion of the preferred shares.

However, we are not obligated to proceed with a demand registration if we have, within the six-month period preceding the date of such request, already effected a registration under the Securities Act pursuant to the exercise of the holders’ demand registration rights or Form F-3 or S-3 registration rights, or in which the holders had an opportunity to participate in the piggyback registration rights, unless the registrable securities of the

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holders were excluded from such registration. We have the right to defer filing of a registration statement for up to 90 days if our board of directors determines in good faith that the filing of a registration statement would be materially detrimental to us and our shareholders, but we cannot exercise the deferral right more than once in any 12-month period. We are obligated to effect only three demand registrations on forms other than Form F-3 or S-3 so long as such registrations have been declared or ordered effective.

F-3 or S-3 registration rights. When we are eligible for registration on Form F-3 or S-3, upon a written request from any holder all registrable securities, we must effect a registration on Form F-3 or S-3 and any related qualification or compliance covering the offer and sale of the registrable securities.

We are not obligated to effect a Form F-3 or S-3 registration, among other things, if we have, within the 12-month period preceding the date of the request, already effected two registrations under the Securities Act or if the holders of Registrable securities proposed to sell at an aggregate price to the public less than $2,000,000. We have the right to defer filing of a registration statement for up to 90 days if our board of directors determines in good faith that the filing of a registration statement would be materially detrimental to us and our shareholders, but we cannot exercise the deferral right more than once in any 12-month period.

Piggyback registration rights. If we propose to file a registration statement under the Securities Act for purposes of effecting a public offering of our securities (including, but not limited to, registration statements relating to secondary offerings of our securities, but excluding registration statements relating to any employee benefit plan, a corporate reorganization or this offering), we must afford holders of registrable securities an opportunity to include in that registration all or any part of their registrable securities then held. We have the right to terminate or withdraw any registration initiated by us under the piggyback registration rights prior to the effectiveness of such registration whether or not any holder has elected to include securities in such registration. The underwriters of any underwritten offering have the right to limit the number of shares with registration rights to be included in the registration statement, subject to certain limitations.

Expenses of registration. We will pay all expenses relating to any demand, Form F-3 or S-3, or piggyback registration except for the underwriting discounts and selling commissions applicable to the sale of registrable securities and certain other limited exceptions.

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DESCRIPTION OF AMERICAN DEPOSITARY SHARES

Citibank, N.A. acts as the depositary bank for the American Depositary Shares. Citibank’s depositary offices are located at 388 Greenwich Street, New York, New York 10013. American Depositary Shares are frequently referred to as “ADSs” and represent ownership interests in securities that are on deposit with the depositary bank. ADSs may be represented by certificates that are commonly known as “American Depositary Receipts” or “ADRs.” The depositary bank typically appoints a custodian to safekeep the securities on deposit. In this case, the custodian is Citibank, N.A.—Hong Kong, located at 9/F., Citi Tower, One Bay East, 83 Hoi Bun Road, Kwun Tong, Kowloon, Hong Kong.

We have appointed Citibank as depositary bank pursuant to a deposit agreement. A draft copy of the deposit agreement is on file with the SEC under cover of a Registration Statement on Form F-6. ADS holders may obtain a copy of the deposit agreement from the SEC’s Public Reference Room at 100 F Street, N.E., Washington, D.C. 20549 and from the SEC’s website (www.sec.gov). Please refer to Registration Number 333-220256 when retrieving such draft copy.

We are providing ADS holders with a summary description of the material terms of the ADSs and of ADS holders’ material rights as an owner of ADSs. Please remember that summaries by their nature lack the precision of the information summarized and that the rights and obligations of an owner of ADSs will be determined by reference to the terms of the deposit agreement and not by this summary. We urge ADS holders to review the deposit agreement in its entirety. The portions of this summary description that are italicized describe matters that may be relevant to the ownership of ADSs but that may not be contained in the deposit agreement.

Each ADS represents the right to receive, and to exercise the beneficial ownership interests in, one ordinary share that is on deposit with the depositary bank and/or custodian. An ADS also represents the right to receive, and to exercise the beneficial interests in, any other property received by the depositary bank or the custodian on behalf of the owner of the ADS but that has not been distributed to the owners of ADSs because of legal restrictions or practical considerations. We and the depositary bank may agree to change the ADS-to-share ratio by amending the deposit agreement. This amendment may give rise to, or change, the depositary fees payable by ADS owners. The custodian, the depositary bank and their respective nominees will hold all deposited property for the benefit of the holders and beneficial owners of ADSs. The deposited property does not constitute the proprietary assets of the depositary bank, the custodian or their nominees. Beneficial ownership in the deposited property will under the terms of the deposit agreement be vested in the beneficial owners of the ADSs. The depositary bank, the custodian and their respective nominees will be the record holders of the deposited property represented by the ADSs for the benefit of the holders and beneficial owners of the corresponding ADSs. A beneficial owner of ADSs may or may not be the holder of ADSs. Beneficial owners of ADSs will be able to receive, and to exercise beneficial ownership interests in, the deposited property only through the registered holders of the ADSs, the registered holders of the ADSs (on behalf of the applicable ADS owners) only through the depositary bank, and the depositary bank (on behalf of the owners of the corresponding ADSs) directly, or indirectly, through the custodian or their respective nominees, in each case upon the terms of the deposit agreement.

An ADSs holder will become a party to the deposit agreement and therefore will be bound to its terms and to the terms of any ADR that represents such ADSs. The deposit agreement and the ADR specify our rights and obligations as well as ADS holders’ rights and obligations as owner of ADSs and those of the depositary bank. ADS holders appoint the depositary bank to act on their behalf in certain circumstances. The deposit agreement and the ADRs are governed by New York law. However, our obligations to the holders of ordinary shares will continue to be governed by the laws of the Cayman Islands, which may be different from the laws in the United States.

In addition, applicable laws and regulations may require ADS holders to satisfy reporting requirements and obtain regulatory approvals in certain circumstances. ADS holders are solely responsible for complying with

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such reporting requirements and obtaining such approvals. Neither the depositary bank, the custodian, us or any of their or our respective agents or affiliates shall be required to take any actions whatsoever on ADS holders’ behalf to satisfy such reporting requirements or obtain such regulatory approvals under applicable laws and regulations.

We will not treat ADS holders as our shareholders and ADS holders will not have direct shareholder rights. The depositary bank will hold on ADS holders’ behalf the shareholder rights attached to the ordinary shares underlying the ADSs. ADS holders will be able to exercise the shareholders rights for the ordinary shares represented by the ADSs through the depositary bank only to the extent contemplated in the deposit agreement. To exercise any shareholder rights not contemplated in the deposit agreement, an ADS holder will, as an ADS owner, need to arrange for the cancellation of such ADSs and become a direct shareholder.

The manner in which ADS holders own the ADSs (e.g., in a brokerage account vs. as registered holder, or as holder of certificated vs. uncertificated ADSs) may affect the holders’ rights and obligations, and the manner in which, and extent to which, the depositary bank’s services are made available to the holders. An ADS holder may hold the ADSs either by means of an ADR registered in such holder’s name, through a brokerage or safekeeping account, or through an account established by the depositary bank in such holder’s name reflecting the registration of uncertificated ADSs directly on the books of the depositary bank (commonly referred to as the “direct registration system” or “DRS”). The direct registration system reflects the uncertificated (book-entry) registration of ownership of ADSs by the depositary bank. Under the direct registration system, ownership of ADSs is evidenced by periodic statements issued by the depositary bank to the holders of the ADSs. The direct registration system includes automated transfers between the depositary bank and The Depository Trust Company (“DTC”), the central book-entry clearing and settlement system for equity securities in the United States. If an ADS holder decides to hold the ADSs through such holder’s brokerage or safekeeping account, the holder must rely on the procedures of his/her broker or bank to assert his/her rights as an ADS owner. Banks and brokers typically hold securities such as the ADSs through clearing and settlement systems such as DTC. The procedures of such clearing and settlement systems may limit an ADS holder’s ability to exercise such holder’s rights as an owner of ADSs. ADS holders should consult with their broker or bank if they have any questions concerning these limitations and procedures. All ADSs held through DTC will be registered in the name of a nominee of DTC. This summary description assumes ADS holders have opted to own the ADSs directly by means of ADSs registered in such holders’ name and, as such, we will refer to ADS holders as the “holders.”

The registration of the ordinary shares in the name of the depositary bank or the custodian shall, to the maximum extent permitted by applicable law, vest in the depositary bank or the custodian the record ownership in the applicable ordinary shares with the beneficial ownership rights and interests in such ordinary shares being at all times vested with the beneficial owners of the ADSs representing the ordinary shares. The depositary bank or the custodian shall at all times be entitled to exercise the beneficial ownership rights in all deposited property, in each case only on behalf of the holders and beneficial owners of the ADSs representing the deposited property.

Dividends and distributions

Holders of ADSs generally have the right to receive the distributions we make on the securities deposited with the custodian. ADS holders’ receipt of these distributions may be limited, however, by practical considerations and legal limitations. Holders of ADSs will receive such distributions under the terms of the deposit agreement in proportion to the number of ADSs held as of the specified record date, after deduction of the applicable fees, taxes and expenses.

Distributions of cash

Whenever we make a cash distribution for the securities on deposit with the custodian, we will deposit the funds with the custodian. Upon receipt of confirmation of the deposit of the requisite funds, the depositary bank will arrange for the funds received in a currency other than U.S. dollars to be converted into U.S. dollars and for the distribution of the U.S. dollars to the holders, subject to Cayman Islands laws and regulations.

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The conversion into U.S. dollars will take place only if practicable and if the U.S. dollars are transferable to the United States. The depositary bank will apply the same method for distributing the proceeds of the sale of any property (such as undistributed rights) held by the custodian in respect of securities on deposit.

The distribution of cash will be made net of the fees, expenses, taxes and governmental charges payable by holders under the terms of the deposit agreement. The depositary bank will hold any cash amounts it is unable to distribute in a non-interest bearing account for the benefit of the applicable holders and beneficial owners of ADSs until the distribution can be effected or the funds that the depositary bank holds must be escheated as unclaimed property in accordance with the laws of the relevant states of the United States.

Distributions of shares

Whenever we make a free distribution of ordinary shares for the securities on deposit with the custodian, we will deposit the applicable number of ordinary shares with the custodian. Upon receipt of confirmation of such deposit, the depositary bank will either distribute to holders new ADSs representing the ordinary shares deposited or modify the ADS-to-ordinary share ratio, in which case each ADS holders hold will represent rights and interests in the additional ordinary shares so deposited. Only whole new ADSs will be distributed. Fractional entitlements will be sold and the proceeds of such sale will be distributed as in the case of a cash distribution.

The distribution of new ADSs or the modification of the ADS-to-ordinary share ratio upon a distribution of ordinary shares will be made net of the fees, expenses, taxes and governmental charges payable by holders under the terms of the deposit agreement. In order to pay such taxes or governmental charges, the depositary bank may sell all or a portion of the new ordinary shares so distributed.

No such distribution of new ADSs will be made if it would violate a law (e.g., the U.S. securities laws) or if it is not operationally practicable. If the depositary bank does not distribute new ADSs as described above, it may sell the ordinary shares received upon the terms described in the deposit agreement and will distribute the proceeds of the sale as in the case of a distribution of cash.

Distributions of rights

Whenever we intend to distribute rights to subscribe for additional ordinary shares, we will give prior notice to the depositary bank and we will assist the depositary bank in determining whether it is lawful and reasonably practicable to distribute rights to subscribe for additional ADSs to holders.

The depositary bank will establish procedures to distribute rights to subscribe for additional ADSs to holders and to enable such holders to exercise such rights if it is lawful and reasonably practicable to make the rights available to holders of ADSs, and if we provide all of the documentation contemplated in the deposit agreement (such as opinions to address the lawfulness of the transaction). Holders may have to pay fees, expenses, taxes and other governmental charges to subscribe for the new ADSs upon the exercise of such rights. The depositary bank is not obligated to establish procedures to facilitate the distribution and exercise by holders of rights to subscribe for new ordinary shares other than in the form of ADSs.

The depositary bank will not distribute the rights to holders if:

The depositary bank will sell the rights that are not exercised or not distributed if such sale is lawful and reasonably practicable. The proceeds of such sale will be distributed to holders as in the case of a cash distribution. If the depositary bank is unable to sell the rights, it will allow the rights to lapse.

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Elective distributions

Whenever we intend to distribute a dividend payable at the election of shareholders either in cash or in additional shares, we will give prior notice thereof to the depositary bank and will indicate whether we wish the elective distribution to be made available to holders. In such case, we will assist the depositary bank in determining whether such distribution is lawful and reasonably practicable.

The depositary bank will make the election available to holders only if it is reasonably practicable and if we have provided all of the documentation contemplated in the deposit agreement. In such case, the depositary bank will establish procedures to enable holders to elect to receive either cash or additional ADSs, in each case as described in the deposit agreement.

If the election is not made available to holders, holders will receive either cash or additional ADSs, depending on what a shareholder in the Cayman Islands would receive upon failing to make an election, as more fully described in the deposit agreement.

Other distributions

Whenever we intend to distribute property other than cash, ordinary shares or rights to subscribe for additional ordinary shares, we will notify the depositary bank in advance and will indicate whether we wish such distribution to be made to holders. If so, we will assist the depositary bank in determining whether such distribution to holders is lawful and reasonably practicable.

If it is reasonably practicable to distribute such property to holders and if we provide to the depositary bank all of the documentation contemplated in the deposit agreement, the depositary bank will distribute the property to holders in a manner it deems practicable.

The distribution will be made net of fees, expenses, taxes and governmental charges payable by holders under the terms of the deposit agreement. In order to pay such taxes and governmental charges, the depositary bank may sell all or a portion of the property received.

The depositary bank will not distribute the property to holders and will sell the property if:

Redemption

Whenever we decide to redeem any of the securities on deposit with the custodian, we will notify the depositary bank in advance. If it is practicable and if we provide all of the documentation contemplated in the deposit agreement, the depositary bank will provide notice of the redemption to holders.

The custodian will be instructed to surrender the shares being redeemed against payment of the applicable redemption price. The depositary bank will convert into U.S. dollars upon the terms of the deposit agreement the redemption funds received in a currency other than U.S. dollars and will establish procedures to enable holders to receive the net proceeds from the redemption upon surrender of their ADSs to the depositary bank. Holders may have to pay fees, expenses, taxes and other governmental charges upon the redemption of the ADSs. If less than all ADSs are being redeemed, the ADSs to be retired will be selected by lot or on a pro rata basis, as the depositary bank may determine.

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Changes affecting ordinary shares

The ordinary shares held on deposit for the ADSs may change from time to time. For example, there may be a change in nominal or par value, split-up, cancellation, consolidation or any other reclassification of such ordinary shares or a recapitalization, reorganization, merger, consolidation or sale of assets of the Company.

If any such change were to occur, the ADSs would, to the extent permitted by law and the deposit agreement, represent the right to receive the property received or exchanged in respect of the ordinary shares held on deposit. The depositary bank may in such circumstances deliver new ADSs to holders, amend the deposit agreement, the ADRs and the applicable Registration Statement(s) on Form F-6, call for the exchange of holders’ existing ADSs for new ADSs and take any other actions that are appropriate to reflect as to the ADSs the change affecting the ordinary shares. If the depositary bank may not lawfully distribute such property to holders, the depositary bank may sell such property and distribute the net proceeds to holders as in the case of a cash distribution.

Issuance of ADSs upon deposit of ordinary shares

Our ordinary shares have been and will be deposited with the custodian. The depositary bank may create ADSs on a holder’s behalf if such holder or such holder’s broker deposits ordinary shares with the custodian. The depositary bank will deliver these ADSs to the person such holder indicates only after such holder pays any applicable issuance fees and any charges and taxes payable for the transfer of the ordinary shares to the custodian. Holders’ ability to deposit ordinary shares and receive ADSs may be limited by U.S. and Cayman Islands legal considerations applicable at the time of deposit.

The issuance of ADSs may be delayed until the depositary bank or the custodian receives confirmation that all required approvals have been given and that the ordinary shares have been duly transferred to the custodian. The depositary bank will only issue ADSs in whole numbers.

When a holder makes a deposit of ordinary shares, such holder will be responsible for transferring good and valid title to the depositary bank. As such, the holder will be deemed to represent and warrant that:

If any of the representations or warranties are incorrect in any way, we and the depositary bank may, at holders’ cost and expense, take any and all actions necessary to correct the consequences of the misrepresentations.

Transfer, combination and split up of ADRs

Holders will be entitled to transfer, combine or split up their ADRs and the ADSs evidenced thereby. For transfers of ADRs, a holder will have to surrender the ADRs to be transferred to the depositary bank and also must:

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To have the ADRs either combined or split up, a holder must surrender his/her ADRs in question to the depositary bank with such holder’s request to have them combined or split up, and such holder must pay all applicable fees, charges and expenses payable by ADR holders, pursuant to the terms of the deposit agreement, upon a combination or split up of ADRs.

Withdrawal of ordinary shares upon cancellation of ADSs

Holders will be entitled to present their ADSs to the depositary bank for cancellation and then receive the corresponding number of underlying ordinary shares at the custodian’s offices. Holders’ ability to withdraw the ordinary shares held in respect of the ADSs may be limited by U.S. and Cayman Islands legal considerations applicable at the time of withdrawal. In order to withdraw the ordinary shares represented by the ADSs, holders will be required to pay to the depositary bank the fees for cancellation of ADSs and any charges and taxes payable upon the transfer of the ordinary shares. Holders assume the risk for delivery of all funds and securities upon withdrawal. Once canceled, the ADSs will not have any rights under the deposit agreement.

If a holder holds ADSs registered in his/her name, the depositary bank may ask such holder to provide proof of identity and genuineness of any signature and such other documents as the depositary bank may deem appropriate before it will cancel the ADSs. The withdrawal of the ordinary shares represented by the ADSs may be delayed until the depositary bank receives satisfactory evidence of compliance with all applicable laws and regulations. Please keep in mind that the depositary bank will only accept ADSs for cancellation that represent a whole number of securities on deposit.

Holders will have the right to withdraw the securities represented by the ADSs at any time except for:

The deposit agreement may not be modified to impair holders’ right to withdraw the securities represented by the ADSs except to comply with mandatory provisions of law.

Voting rights

Holders generally have the right under the deposit agreement to instruct the depositary bank to exercise the voting rights for the ordinary shares represented by ADSs. The voting rights of holders of ordinary shares are described in “Description of Share Capital.”

At our request, the depositary bank will distribute to holders any notice of shareholders’ meeting received from us together with information explaining how to instruct the depositary bank to exercise the voting rights of the securities represented by ADSs. In lieu of distributing such materials, the depositary bank may distribute to holders instructions on how to retrieve such materials upon request.

If the depositary bank timely receives voting instructions from a holder, it will endeavor to vote the securities (in person or by proxy) represented by the holder’s ADSs in accordance with such voting instructions as follows:

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In the event of voting by poll, holders in respect of which no timely voting instructions have been received shall be deemed to have instructed the depositary bank to give a discretionary proxy to a person designated by us to vote the ordinary shares represented by such holders’ ADSs; provided, that no such instructions shall be deemed given and no such discretionary proxy shall be given with respect to any matter as to which we inform the depositary bank that we do not wish such proxy to be given; provided, further, that no such discretionary proxy shall be given (x) with respect to any matter as to which we inform the depositary that (i) there exists substantial opposition, or (ii) the rights of holders or the shareholders of our company may be materially adversely affected, and (y) in the event that the vote is on a show of hands.

Please note that the ability of the depositary bank to carry out voting instructions may be limited by practical and legal limitations and the terms of the securities on deposit. We cannot assure that holders will receive voting materials in time to enable them to return voting instructions to the depositary bank in a timely manner.

Fees and charges

Holders will be required to pay the following fees under the terms of the deposit agreement:

Holders will also be responsible to pay certain charges such as:

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ADS fees and charges payable upon (i) the issuance of ADSs, and (ii) the cancellation of ADSs are charged to the person to whom the ADSs are issued (in the case of ADS issuances) and to the person whose ADSs are cancelled (in the case of ADS cancellations). In the case of ADSs issued by the depositary bank into DTC, the ADS issuance and cancellation fees and charges may be deducted from distributions made through DTC, and may be charged to the DTC participant(s) receiving the ADSs being issued or the DTC participant(s) holding the ADSs being cancelled, as the case may be, on behalf of the beneficial owner(s) and will be charged by the DTC participant(s) to the account of the applicable beneficial owner(s) in accordance with the procedures and practices of the DTC participants as in effect at the time. ADS fees and charges in respect of distributions and the ADS service fee are charged to the holders as of the applicable ADS record date. In the case of distributions of cash, the amount of the applicable ADS fees and charges is deducted from the funds being distributed. In the case of (i) distributions other than cash and (ii) the ADS service fee, holders as of the ADS record date will be invoiced for the amount of the ADS fees and charges and such ADS fees and charges may be deducted from distributions made to holders of ADSs. For ADSs held through DTC, the ADS fees and charges for distributions other than cash and the ADS service fee may be deducted from distributions made through DTC, and may be charged to the DTC participants in accordance with the procedures and practices prescribed by DTC and the DTC participants in turn charge the amount of such ADS fees and charges to the beneficial owners for whom they hold ADSs.

In the event of refusal to pay the depositary bank fees, the depositary bank may, under the terms of the deposit agreement, refuse the requested service until payment is received or may set off the amount of the depositary bank fees from any distribution to be made to holders. Certain of the depositary fees and charges (such as the ADS services fee) may become payable shortly after the closing of an ADS offering. Note that the fees and charges holders may be required to pay may vary over time and may be changed by us and by the depositary bank. Holders will receive prior notice of such changes. The depositary bank may reimburse us for certain expenses incurred by us in respect of the ADR program, by making available a portion of the ADS fees charged in respect of the ADR program or otherwise, upon such terms and conditions as we and the depositary bank agree from time to time.

Amendments and termination

We may agree with the depositary bank to modify the deposit agreement at any time without holders’ consent. We undertake to give holders 30 days’ prior notice of any modifications that would materially prejudice any of their substantial rights under the deposit agreement. We will not consider to be materially prejudicial to holders’ substantial rights any modifications or supplements that are reasonably necessary for the ADSs to be registered under the Securities Act or to be eligible for book-entry settlement, in each case without imposing or increasing the fees and charges holders are required to pay. In addition, we may not be able to provide holders with prior notice of any modifications or supplements that are required to accommodate compliance with applicable provisions of law.

Holders will be bound by the modifications to the deposit agreement if they continue to hold their ADSs after the modifications to the deposit agreement become effective. The deposit agreement cannot be amended to prevent holders from withdrawing the ordinary shares represented by the ADSs (except as permitted by law).

We have the right to direct the depositary bank to terminate the deposit agreement. Similarly, the depositary bank may in certain circumstances on its own initiative terminate the deposit agreement. In either case, the depositary bank must give notice to holders at least 30 days before termination. Until termination, holders’ rights under the deposit agreement will be unaffected.

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After termination, the depositary bank will continue to collect distributions received (but will not distribute any such property until holders request the cancellation of their ADSs) and may sell the securities held on deposit. After the sale, the depositary bank will hold the proceeds from such sale and any other funds then held for the holders of ADSs in a non-interest bearing account. At that point, the depositary bank will have no further obligations to holders other than to account for the funds then held for the holders of ADSs still outstanding (after deduction of applicable fees, taxes and expenses).

Books of depositary

The depositary bank will maintain ADS holder records at its depositary office. Holders may inspect such records at such office during regular business hours but solely for the purpose of communicating with other holders in the interest of business matters relating to the ADSs and the deposit agreement.

The depositary bank will maintain in New York facilities to record and process the issuance, cancellation, combination, split-up and transfer of ADSs. These facilities may be closed from time to time, to the extent not prohibited by law.

Limitations on obligations and liabilities

The deposit agreement limits our obligations and the depositary bank’s obligations to holders. Please note the following:

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As the above limitations relate to our obligations and the depositary’s obligations to you under the deposit agreement, we believe that, as a matter of construction of the clause, such limitations would likely to continue to apply to ADS holders who withdraw the ordinary shares from the ADS facility with respect to obligations or liabilities incurred under the deposit agreement before the cancellation of the ADSs and the withdrawal of the ordinary shares, and such limitations would most likely not apply to ADS holders who withdraw the ordinary shares from the ADS facility with respect to obligations or liabilities incurred after the cancellation of the ADSs and the withdrawal of the ordinary shares and not under the deposit agreement.

In any event, you will not be deemed, by agreeing to the terms of the deposit agreement, to have waived our or the depositary’s compliance with U.S. federal securities laws and the rules and regulations promulgated thereunder. In fact, you cannot waive our or the depositary’s compliance with U.S. federal securities laws and the rules and regulations promulgated thereunder.

Pre-release transactions

While the deposit agreement provides for pre-release transactions, the depositary bank has confirmed to us that it does not presently engage in pre-release transactions and will not do so absent our consent. We do not intend to permit the depositary bank to enter into pre-release transactions.

Taxes

Holders will be responsible for the taxes and other governmental charges payable on the ADSs and the securities represented by the ADSs. We, the depositary bank and the custodian may deduct from any distribution the taxes and governmental charges payable by holders and may sell any and all property on deposit to pay the taxes and governmental charges payable by holders. Holders will be liable for any deficiency if the sale proceeds do not cover the taxes that are due.

The depositary bank may refuse to issue ADSs, to deliver, transfer, split and combine ADRs or to release securities on deposit until all taxes and charges are paid by the applicable holder. The depositary bank and the custodian may take reasonable administrative actions to obtain tax refunds and reduced tax withholding for any distributions on holders’ behalf. However, holders may be required to provide to the depositary bank and to the custodian proof of taxpayer status and residence and such other information as the depositary bank and the custodian may require to fulfill legal obligations. Holders are required to indemnify us, the depositary bank and the custodian for any claims with respect to taxes arising out of any refund of taxes, reduced rate of withholding or of the tax benefit obtained for or by the holders.

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Foreign currency conversion

The depositary bank will arrange for the conversion of all foreign currency received into U.S. dollars if such conversion is practicable, and it will distribute the U.S. dollars in accordance with the terms of the deposit agreement. Holder may have to pay fees and expenses incurred in converting foreign currency, such as fees and expenses incurred in complying with currency exchange controls and other governmental requirements.

If the conversion of foreign currency is not practical or lawful, or if any required approvals are denied or not obtainable at a reasonable cost or within a reasonable period, the depositary bank may take the following actions in its discretion:

Governing law/waiver of jury trial

The deposit agreement and the ADRs will be interpreted in accordance with the laws of the State of New York. The rights of holders of ordinary shares (including ordinary shares represented by ADSs) is governed by the laws of the Cayman Islands.

By holding an ADS or an interest therein, ADS holders irrevocably agree that any legal suit, action or proceeding against or involving us or the Depositary, arising out of or based upon the deposit agreement, ADSs or ADRs, may only be instituted in a state or federal court in New York, New York, and ADS holders irrevocably waive any objection to the laying of venue and irrevocably submit to the exclusive jurisdiction of such courts with respect to any such suit, action or proceeding.

AS A PARTY TO THE DEPOSIT AGREEMENT, ADS HOLDERS IRREVOCABLY WAIVE, TO THE FULLEST EXTENT PERMITTED BY APPLICABLE LAW, THE RIGHT TO TRIAL BY JURY IN ANY LEGAL PROCEEDING ARISING OUT OF THE DEPOSIT AGREEMENT, THE ADRs AND ANY TRANSACTIONS CONTEMPLATED THEREIN (WHETHER BASED ON CONTRACT, TORT, COMMON LAW OR OTHERWISE) AGAINST US AND/OR THE DEPOSITARY BANK.

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TAXATION

Tax considerations relating to the ownership and disposition of any of the securities offered by this prospectus will be set forth in the applicable prospectus supplement relating to the offering of those securities.

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PLAN OF DISTRIBUTION

We and any selling shareholders may sell the securities offered by this prospectus:

The prospectus supplement relating to any offering will identify or describe:

Underwriters

If we or any selling shareholders use underwriters in the sale, we or the selling shareholders will enter into an underwriting agreement, and a prospectus supplement will set forth the names of the underwriters and the terms of the transaction. The underwriters will acquire securities for their own account and may resell the securities from time to time in one or more transactions, including negotiated transactions, at a fixed public offering price or at varying prices determined at the time of sale. Unless otherwise stated in the prospectus supplement, various conditions to the underwriters’ obligation to purchase securities apply, and the underwriters will be obligated to purchase all of the securities contemplated in an offering if they purchase any of such securities. Any initial public offering price and any discounts or concessions allowed or reallowed or paid to dealers may be changed from time to time.

We or any selling shareholders may enter into derivative or other hedging transactions with third parties, or sell securities not covered by this prospectus to third parties in privately negotiated transactions. If the applicable prospectus supplement indicates, in connection with those derivatives, the third parties may sell securities covered by this prospectus and the applicable prospectus supplement, including in short sale transactions. If so, the third party may use securities covered by this prospectus including securities pledged by us or any selling shareholders or borrowed from us, any selling shareholders or others to settle those sales or to close out any related open borrowing of stock, and may use securities received from us in settlement of those derivatives to close out any related open borrowings of stock. The third party in such sale transactions will be an underwriter and, if not identified in this prospectus, will be identified in the applicable prospectus supplement (or in a post-effective amendment). We or any selling shareholders may also sell ordinary shares short using this prospectus and deliver ordinary shares covered by this prospectus to close out such short positions, or loan or pledge ordinary shares to financial institutions that in turn may sell the ordinary shares using this prospectus. We or any selling shareholders may pledge or grant a security interest in some or all of the securities covered by this prospectus to support a derivative or hedging position or other obligation and, if we or the selling shareholders default in the performance of its obligations, the pledgees or secured parties may offer and sell the securities from time to time pursuant to this prospectus.

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If the prospectus supplement so indicates, we or any selling shareholders may authorize agents and underwriters or dealers to solicit offers by certain purchasers to purchase the securities from us at the public offering price set forth in the prospectus supplement. These contracts will be subject to only those conditions set forth in the prospectus supplement, and the prospectus supplement will set forth the commission payable for solicitation of such offers.

Certain persons participating in this offering may engage in transactions that stabilize, maintain or otherwise affect the price of the securities. Specifically, the underwriters, if any, may over-allot in connection with the offering, and may bid for, and purchase, the securities in the open market.

Dealers

If we or any selling shareholders use dealers in the sale, unless otherwise indicated in the prospectus supplement, we or the selling shareholders will sell securities to the dealers as principals. The dealers may then resell the securities to the public at varying prices that the dealers may determine at the time of resale.

Agents and Direct Sales

We or any selling shareholders may sell securities directly or through agents that we or the selling shareholders designate. The prospectus supplement names any agent involved in the offering and sale and states any commissions we or the selling shareholders will pay to that agent. Unless indicated otherwise in the prospectus supplement, any agent is acting on a best efforts basis for the period of its appointment.

Institutional Investors

Unless otherwise indicated in the prospectus supplement, we or any selling shareholders will authorize underwriters, dealers or agents to solicit offers from various institutional investors to purchase securities. In this case, payment and delivery will be made on a future date that the prospectus supplement specifies. The underwriters, dealers or agents may impose limitations on the minimum amount that the institutional investor can purchase. They may also impose limitations on the portion of the aggregate amount of the securities that they may sell. These institutional investors include:

The obligations of any of these purchasers pursuant to delayed delivery and payment arrangements will not be subject to any conditions. However, one exception applies. An institution’s purchase of the particular securities cannot at the time of delivery be prohibited under the laws of any jurisdiction that governs:

Indemnification

Agreements that we or any selling shareholders have entered into or may enter into with underwriters, dealers or agents may entitle them to indemnification by us against various civil liabilities. These include liabilities under the Securities Act of 1933, as amended. The agreements may also entitle them to contribution for payments which they may be required to make as a result of these liabilities. Underwriters, dealers or agents may be customers of, engage in transactions with, or perform services for, us in the ordinary course of business.

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LEGAL MATTERS

We are being represented by Davis Polk & Wardwell LLP with respect to legal matters of United States federal securities and New York State law. Certain legal matters in connection with any offering made pursuant to this prospectus will be passed upon for the underwriters by a law firm named in the applicable prospectus supplement. The validity of ordinary shares offered in any offering made pursuant to this prospectus and legal matters as to Cayman Islands law will be passed upon for us by Travers Thorp Alberga.

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EXPERTS

The consolidated financial statements incorporated in this prospectus by reference from our annual report on Form 10-K for the year ended December 31, 2020, and the effectiveness of our internal control over financial reporting as of December 31, 2020, have been audited by Deloitte Touche Tohmatsu Certified Public Accountants LLP, an independent registered public accounting firm, as stated in their report, which is incorporated herein by reference. Such financial statements have been so incorporated in reliance upon the reports of such firm given upon their authority as experts in accounting and auditing.

The office of Deloitte Touche Tohmatsu Certified Public Accountants LLP is located at 30/F Bund Center, 222 East Yan An Road, Shanghai 200002, People’s Republic of China.

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WHERE YOU CAN FIND MORE INFORMATION

We file annual, quarterly and current reports, proxy statements and other information with the SEC. Our SEC filings are available to the public over the Internet at the SEC’s website at www.sec.gov. Copies of certain information filed by us with the SEC are also available on our website at www.zailaboratory.com. Our website is not a part of this prospectus and is not incorporated by reference in this prospectus.

This prospectus is part of a registration statement we filed with the SEC. This prospectus omits some information contained in the registration statement in accordance with SEC rules and regulations. You should review the information and exhibits in the registration statement for further information about us and the securities we are offering. Statements in this prospectus concerning any document we filed as an exhibit to the registration statement or that we otherwise filed with the SEC are not intended to be comprehensive and are qualified by reference to these filings. You should review the complete document to evaluate these statements. Whenever a reference is made in this prospectus to a contract or other document of Zai Lab Limited, the reference is only a summary and you should refer to the exhibits that are a part of the registration statement for a copy of the contract or other document.

Our ADSs are listed on the Nasdaq Global Market. Our ordinary shares are listed on The Stock Exchange of Hong Kong Limited. You can consult reports and other information about Zai Lab Limited that it filed pursuant to the rules.

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INCORPORATION OF DOCUMENTS BY REFERENCE

The SEC allows us to incorporate by reference the information we file with them. This means that we can disclose important information to you by referring to documents. The information that we incorporate by reference is an important part of this prospectus. We incorporate by reference the following documents and any future filings that we make with the SEC under Sections 13(a), 13(c), 14 and 15(d) of the Securities Exchange Act of 1934, as amended, until we complete the offerings using this prospectus:

Information that we file with the SEC will automatically update and supersede the information included in this prospectus or previously incorporated by reference into this prospectus. All information appearing in this prospectus is qualified in its entirety by the information and financial statements, including the notes, contained in the documents that we incorporate by reference in this prospectus.

You may request a copy of these filings by writing or telephoning us at the following address:

Zai Lab Limited

4560 Jinke Road

Bldg. 1, Fourth Floor

Pudong

Shanghai, China 201210

+86 21 6163 2588

You should rely only on the information that we incorporate by reference or provide in this prospectus or the accompanying prospectus supplement. We have not authorized anyone to provide you with different information. You should not assume that the information in this prospectus or any prospectus supplement is accurate as of any date other than the date on the front of those documents.

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