Indicate by check mark whether the registrant (1) has filed all reports required to be filed by Section 13 or 15(d) of the SecuritiesExchange Act of 1934 during the preceding 12 months (or for such shorter period that the registrant was required to file such reports), and (2) Indicate by check mark whether the registrant has submitted electronically every Interactive Data File required to be submittedpursuant to Rule 405 of Regulation S-T (§ 232.405 of this chapter) during the preceding 12 months (or for such shorter period that the Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, a smallerreporting company, or an emerging growth company. See the definitions of “large accelerated filer,” “accelerated filer,” “smaller reporting If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period forcomplying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act.☐ Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Exchange Act). Yes☐No☒ As of May2, 2025,1,084,743,860ordinary shares of the registrant, par value $0.000006 per share, were outstanding, of which486,853,250ordinary shares were held in the form of American Depositary Shares. Zai Lab LimitedQuarterly Report on Form 10-Q PART I.FINANCIAL INFORMATION Item 1.Financial Statements (Unaudited)Condensed Consolidated Balance Sheets as ofMarch 31,2025and December 31, 2024Condensed Consolidated Statements of Operations for the ThreeMonths EndedMarch 31, 2025 and 2024Condensed Consolidated Statements of Comprehensive Loss for the ThreeMonths EndedMarch 31,2025and2024 SPECIAL NOTES REGARDING THE COMPANY Forward-Looking Statements This report contains certain forward-looking statements, including statements relating to our strategy and plans; potential of andexpectations for our business, commercial products, and pipeline programs; the market for our commercial and pipeline products; capitalallocation and investment strategy; clinical development programs and related clinical trials; clinical trial data, data readouts, andpresentations; risks and uncertainties 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 ourcollaboration partners; the anticipated benefits and potential of investments, collaborations, and business development activities; ourprofitability and timeline to profitability; and our future financial and operating results. All statements, other than statements of historicalfact, included in this report are forward-looking statements, and can be identified by words such as “aim,” “anticipate,” “believe,” •Our ability to successfully commercialize and generate revenue from our approved products;•Our ability to obtain funding for our operations and business initiatives;•The results of our clinical and pre-clinical development of our product candidates;•The content and timing of decisions made by the relevant regulatory authorities regarding regulatory approvals of our productcandidates;•Changes in U.S. and China trade policies and relations, as well as relations with other countries, and/or changes in laws, regulations,and/or sanctions;•Actions the Chinese government may take to intervene in or influence our operations;•Economic, political, and social conditions in mainland China as well as governmental policies;•Uncertainties in the Chinese legal system, including with respect to the anti-corruption enforcement efforts in mainland China and theCounter-Espionage Law, the Data Security Law, the Cyber Security Law, the Cybersecurity Review Measures, the PersonalInformation Protection Law, the Regulation on the Administration of Human Genetic Resources, the Biosecurity Law, the SecurityAssessment Measures, and other future laws and regulations or amendments to such laws and regulations;•Approval, filing, or procedural requirements imposed by the China Securities Regulatory Commission or other Chinese regulatory •Restrictions or limitations on the ability of overseas regulators to conduct investigations or collect evidence within mainland China;•Significant business disruptions caused by events or developments outside of our control, such as pandemics, international war orconflict, natural disasters or extreme weather events, and other geopolitical events;•Unfavorable tax consequences to us and our non-Chinese shareholders or ADS holders if we were to be classified as a Chineseresident enterprise for Chinese income tax purposes;•Failure to comply with applicable Chinese, U.S., and Hong Kong regulations that could lead to government enforcement actions,fines, other legal or administrative sanctions, and/or harm to our business or rep