This report contains certain forward-looking statements, that involveincluding statements relating to our strategy and plans; potential of and expectations for our business and pipeline programs; capital allocation and investment strategy; clinical development programs and related clinical trials; clinical trial data, data readouts, and presentations; risks and uncertainties. Theseuncertainties associated with drug development and commercialization; regulatory discussions, submissions, filings, and approvals and the timing thereof; the potential benefits, safety, and efficacy of our products and product candidates and those of our collaboration partners; the anticipated benefits and potential of investments, collaborations, and business development activities; and our future financial and operating results. All statements, other than statements of historical fact, included in this report are forward-looking statements, include, without limitation, statements containingand can be identified by words such as “aim,” “anticipate,” “believe,” “contemplate,” “continue,” “could,” “estimate,” “expect,” “forecast,” “goal,” “intend,” “may,” “plan,” “possible,” “potential,” “predict,” “project,” “seek,” “should,” “target,” “will,” “would,” or the negative of these terms or similar expressions. Such statements constitute forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995. You should read theseForward-looking statements carefully because they discuss future expectations, contain projections of future results of operations or financial condition, or state other “forward-looking” information, that are not statements of historical facts or guarantees or assurances of future performance. These forward-lookingForward-looking statements relate toare based on our future plans, objectives, expectations intentions, and financial performanceassumptions as of the date of this report and the assumptions that underlie these statements. These forward-looking statements are subject to inherent uncertainties, risks, and changes in circumstances that may differ materially from those contemplated by the forward-looking statements because they relate to events and depend on circumstances that may orstatements. We may not occuractually achieve the plans, carry out the intentions, or meet the expectations or projections disclosed in the future.our forward-looking statements, and you should not place undue reliance on these forward-looking statements. Actual results may differ materially from those indicated by such forward-looking statements as a result of various important factors, including but not limited to the following:

•    The effects of the COVID-19 pandemic, particularly in mainland China whereOur ability to successfully commercialize and generate revenue from our approved products;

Usage of Terms

Unless the context requires otherwise, references in this report to “Greater China” refer to mainland China, Hong Kong Special Administrative Region (“Hong Kong” or “HK”), Macau Special Administrative Region (“Macau”), and Taiwan, collectively; references to “Zai Lab,” the “Company,” “we,” “us,” and “our” refer to Zai Lab Limited, a holding company, and its subsidiaries, on a consolidated basis; and references to “Zai Lab Limited” refer to Zai Lab Limited, a holding company. Zai Lab Limited is the entity in which investors hold their interest.

Our operating subsidiaries consist of Zai Lab (Hong Kong) Limited, domiciled in Hong Kong; Zai Auto Immune (Hong Kong) Limited, domiciled in Hong Kong; Zai Anti Infectives (Hong Kong) Limited, domiciled in Hong Kong; Zai Lab (Shanghai) Co., Ltd., domiciled in mainland China; Zai Lab International Trading (Shanghai) Co., Ltd., domiciled in mainland China; Zai Lab (Suzhou) Co., Ltd., domiciled in mainland China; Zai Biopharmaceutical (Suzhou) Co., Ltd., domiciled in mainland China; Zai Lab Trading (Suzhou) Co., Ltd., domiciled in mainland China; Zai Lab (Taiwan) Limited, domiciled in Taiwan; Zai Lab (AUST) Pty. Ltd., domiciled in Australia; and Zai Lab (US) LLC, domiciled in the United States. As of the date of this report, Zai Anti Infectives (Hong Kong) Limited has non-substantial business operations.

We own various registered trademarks, trademark applications, and unregistered trademarks and service marks, including various forms of the “ZAI LAB” and “再鼎医药” brands, as well as domain names incorporating some or all of these trademarks and our corporate logo. All other trade names, trademarks, and service marks of other companies appearing in this report are the property of their respective holders. Solely for convenience, some of the trademarks and trade names in this report are referred to without the ® and ™ symbols, but such references should not be construed as any indicator that their respective owners will not assert, to the fullest extent under applicable law, their rights thereto. We do not intend our use or display of other companies’ trademarks and trade names to imply a relationship with, or endorsement or sponsorship of, any other company.

Disclosures Relating to Our Chinese Operations

Zai Lab Limited is an exempted company incorporated in the Cayman Islands on March 28, 2013 with limited liability. 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. We have substantial operations in mainland China. Below is a summary of certain risks related to our Chinese operations. For more information on these risks and other risks relating to our ADSs and ordinary shares (considered individually or together, “our securities”) and for material regulations that may affect our business and an investment in our securities, see Item 1A. Risk Factors and Item 1. Business – Government Regulation in our 2022 Annual Report.

Zai Lab Limited is not a Chinese operating company, but a holding company incorporated in the Cayman Islands. As a holding company, we conduct a substantial portion of our operations through wholly owned subsidiaries based in mainland China. Our investors do not hold direct investments in our Chinese operating companies. In July 2021, the Chinese government provided new guidance on Chinese companies raising capital outside of mainland China, including through arrangements called variable interest entities (“VIEs”). Currently, our corporate structure contains no VIEs, and the life sciences industry in which we operate is not subject to foreign ownership limitations in mainland China. However, there are uncertainties with respect to the Chinese legal system, and there may be changes in laws, regulations, and policies, including how those laws, regulations, and policies will be interpreted or implemented, that may affect our business or an investment in our business. If, in the future, the Chinese government determines that our corporate structure does not comply with Chinese regulations, or if Chinese regulations change or are interpreted differently, the value of our securities may decline or become worthless.

There are significant legal and operational risks associated with conducting a substantial portion of our operations in mainland China, including with respect to changes in the legal, political, and economic policies of the Chinese government, relations between mainland China and the United States, or Chinese or U.S. regulations. For example, geopolitical events, such as developments with respect to Taiwan, continue to cause heightened tensions between the United States and China. In addition, new laws and regulations, including the Counter-Espionage Law, Personal Information Protection Law, Data Security Law, Cyber Security Law and Cybersecurity Review Measures, Measures on Security Assessment of Cross-Border Data Transfer, and regulations and guidelines relating to the multi-level protection scheme, have imposed, and may continue to impose, additional restrictions or obligations and compliance-related costs on our business. In addition, our business, or our directors or employees, may be subject to enforcement actions or penalties if it is determined that we, or they, have not complied with applicable laws and regulations. Such legal and operational risks may materially and adversely affect our business, financial condition, results of operations, ability to raise capital or continue to offer our securities, and the market price of our securities.

The Chinese government has exercised, and may continue to exercise, substantial influence or control over virtually every sector of the Chinese economy through regulation and state ownership. As a result, we are or may be required to obtain certain approvals or permissions from Chinese authorities to operate in mainland China, transfer certain scientific data, and issue our securities to foreign investors.

For example, we are required to obtain certain approvals from Chinese authorities to operate our Chinese subsidiaries. To operate our general business activities in mainland China, each of our Chinese subsidiaries is required to obtain a business license from the local counterpart of the State Administration for Market Regulation (“SAMR”). Each of our Chinese subsidiaries has obtained such a business license. Our Chinese subsidiaries are also required to obtain certain licenses and permits, including but not limited to the following: Pharmaceutical Manufacturing Permits, Pharmaceutical Distribution Permits, and Medical Device Distribution Permits to manufacture and/or distribute drugs and/or applicable medical devices. No application for any such material license or permit has been denied.

Further, we are required to obtain certain approvals from Chinese authorities before transferring certain scientific data abroad or to foreign parties or entities established or controlled by those foreign parties. In addition, we may be subject to additional such requirements pursuant to the Security Assessment Measures, which may affect our Chinese subsidiaries or clinical trials. The Security Assessment Measures may require us to complete security assessments for certain cross-border data transfers, obtain prior approval from the Cyberspace Administration of China (“CAC”) for transfers out of mainland China of certain important or personal data, or obtain prior clearance or approval from the Human Genetic Resources Administration Office of China (“HGRAC”) for certain transfers of data derived from human organs, tissues, or cells of Chinese individuals that contain human genetic materials. If we are not able to obtain or maintain the necessary permissions or approvals, our ability to operate in mainland China may be restricted or prohibited, and the value of our securities could significantly decline or become worthless.

Although we are not currently required to obtain prior approval or permission from the CSRC or any other Chinese regulatory authority to issue our securities to foreign investors, the CSRC has promulgated a new set of regulations that consists of the Trial Administrative Measures for Overseas Securities Offering and Listing by Domestic Companies (the “Trial Measures”) and five supporting guidelines, which became effective onin March 31, 2023. Pursuant to the Trial Measures, we may be required to submit filings to the CSRC following the submission of future overseas listings and the completion of future offerings of our equity securities to foreign investors. If we are not able to complete the necessary filings for future securities offerings, our ability to raise capital may be adversely affected.

The central or local governments could impose new, stricter regulations or interpretations of existing regulations that could impose additional requirements, require additional approvals or permissions in the future, and result in additional related expenditures and efforts on our part to comply with such regulations or interpretations. Also, as there are uncertainties with respect to the Chinese legal system and changes in laws, regulations, and policies, including how those laws, regulations, and policies will be interpreted or implemented, our business and an investment in our securities could be adversely affected.

The Company’s principal operations and geographic markets are in Greater China. The Company has a substantial presence in Greater China and the United States. The accompanying unaudited condensed consolidated financial statements are the financial statements of the Company.

The accompanying unaudited condensed consolidated financial statements have been prepared in accordance with generally accepted accounting principles in the United States (“U.S. GAAP”), and applicable rules and regulations of the U.S. Securities and Exchange Commission (the “SEC”), regarding interim financial reporting. Certain information and note disclosures normally included in the financial statements prepared in accordance with U.S. GAAP have been condensed or omitted pursuant to such rules and regulations. As such, the information included in this report should be read in conjunction with the consolidated financial statements and accompanying notes included in the Annual Report on Form 10-K for the year ended December 31, 2022 filed with the SEC on March 1, 2023 (the “2022 Annual Report”). The December 31, 2022 condensed consolidated balance sheet data included in this report were derived from the audited financial statements included in the 2022 Annual Report.

In the third quarter of 2022, wethe Company began to separately present the amount of foreign currency remeasurement gain (loss) on our statements of cash flows. This amount was previously included in changes in other current liabilities. This change did not have any impact on net cash used in operating activities. Corresponding amountamounts in the prior periodperiods of the condensed consolidated financial statement hashave been presented to conform to the current period presentation.

The accompanying condensed consolidated financial statements reflect all normal recurring adjustments that are necessary to present fairly the results for the interim periods presented. Interim results are not necessarily indicative of the results for the year ending December 31, 2023.

The unaudited condensed consolidated financial statements include the financial statements of the Company. All intercompany transactions and balances are eliminated upon consolidation.

The preparation of the unaudited condensed consolidated financial statements in conformity with U.S. GAAP requires management to make estimates, judgments, and assumptions that affect the reported amounts of assets and liabilities and disclosures of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the period. Areas where management uses subjective judgment include, but are not limited to, accrual of rebates, recognition of research and development expenses to the appropriate financial reporting period based on the progress of the research and development projects, fair value of share-based compensation expenses, and recoverability of deferred tax assets. These estimates, judgments, and assumptions can affect the reported amounts of assets and liabilities as of the date of the financial statements as well as the reported amounts of revenues and expenses during the periods presented. Actual results could differ from these estimates.

Equity investments with readily determinable fair value are measured using level 1 inputs and were $6.9$4.5 million and $6.4 million as of March 31,September 30, 2023 and December 31, 2022, respectively. The unrealized gains and losses from fair value changes are recognized in other income (expenses), net in the condensed consolidated statements of operations.

Financial instruments of the Company primarily include cash, cash equivalents and restricted cash, short-term investments, accounts receivable, notes receivable, prepayments and other current assets, accounts payable, and other current liabilities. As of March 31,September 30, 2023 and December 31, 2022, the carrying values of cash and cash equivalents, short-term investments, accounts receivable, notes receivable, prepayments and other current assets, accounts payable, and other current liabilities approximated their fair values due to the short-term maturity of these instruments, and the carrying value of restricted cash approximated its fair value based on the nature of the assessment of the ability to recover these amounts.

There were noThe Company has not adopted any new accounting standards adopted since the 2022 Annual Report.

The following table presents the Company’s inventories, net inventory balance was $38.4 million and $31.6 million as of March 31, 2023 and December 31, 2022, respectively, and mainly consisted of finished goods purchased from Tesaro Inc., now GlaxoSmithKline (“GSK”), for distribution($ in Hong Kong, from NovoCure Limited (“NovoCure”) for distribution in Hong Kong and mainland China, and from Deciphera Pharmaceuticals, LLC (“Deciphera”) for distribution in Hong Kong, mainland China and Taiwan, as well as finished goods and certain raw materials for ZEJULA and NUZYRA commercialization in mainland China.thousands):

The Company writes down inventory for any excess or obsolete inventories or when the Company believes that the net realizable value of inventories is less than the carrying value. The Company recorded write-downs in inventory, which were included in cost of sales, of $0.4$0.1 million and $0.1$0.7 million forduring the first quarter ofthree and nine months ended September 30, 2023, respectively, and $0.3 million and $0.5 million during the three and nine months ended September 30, 2022 respectively.

The following table presents the components of the Company’s property and equipment, net ($ in thousands):

Depreciation expense was $2.5$1.8 million and $1.9$6.1 million for the first quarter ofthree and nine months ended September 30, 2023, respectively, and $2.1 million and $5.7 million for the three and nine months ended September 30, 2022, respectively.

The Company’s product revenue is primarily derived from the sales of ZEJULA, Optune, QINLOCK, NUZYRA, and NUZYRAVYVGART in mainland China and Hong Kong. The table below presents the Company’s product revenue ($ in thousands):

Sales rebates are offered to distributors in mainland China, and the amounts are recorded as a reduction of revenue. Estimated rebates are determined based on contracted rates, sales volumes, and level of distributor inventories.

The following table presents the Company’s net revenue by product ($ in thousands):

No provision for income taxes has been required to be accrued because the Company and all of its subsidiaries areis in a cumulative loss positionsposition for the periods presented.

The Company recorded a full valuation allowance against deferred tax assets of all its consolidated entities because all entities were in a cumulative loss position as of March 31,September 30, 2023 and December 31, 2022. No unrecognized tax benefits and related interest and penalties were recorded in the periods presented.

The following table presents the Company’s other current liabilities ($ in thousands):

The following table presents the computation of the basic and diluted net loss per share ($ in thousands, except share and per share data):

The Company incurred research and development expenses for product research and development services provided by MEDx (Suzhou) Translational Medicine Co., Ltd (“MEDx”), over which an immediate family member of our Chief Executive Officer and Chairperson of the Board held significant influence. The Company incurred development expenses with MEDx of nil and $0.1an insignificant amount during the three and nine months ended September 30, 2023 and an insignificant amount and $0.3 million during the first quarter of 2023three and nine months ended September 30, 2022, respectively.

In March 2015,During the Board of Directors ofnine months ended September 30, 2023, the Company approved an Equity Incentive Plan (the “2015 Plan”), pursuant to which the Board of Directors could grantgranted share options to purchase up to 23,768,090 ordinary shares to management including officers, directors, employees, and individual advisors who rendered services to the Company. In August 2017, in connection with the completion of the Company’s initial public offering on Nasdaq (the “IPO”), the Board of Directors approved the 2017 Equity Incentive Plan (the “2017 Plan”). All equity-based awards subsequent to the IPO would be granted under the 2017 Plan. The 2017 Plan provided for an automatic annual increase to the number ofrestricted shares representing 8,836,580 ordinary shares reserved under the 2017 Plan on each January 1st between January 1, 2018 and January 1, 2027 equal to the lesser of 4% of the number of ordinary shares outstanding as of the close of business on the immediately prior December 31st or such number as approved by the Board on or prior to such date each year.

The following table presents the stock-basedshare-based compensation expense that has been reported in the Company’s condensed consolidated statements of operations and comprehensive loss as follows ($ in thousands):