Zai Lab Ltd

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 10-K

(Mark One)

For the fiscal year ended: December 31, 2025

Or

For the transition period from [ ] to [ ]

Commission file number:001-38205

ZAI LAB LIMITED

(Exact Name of Registrant as Specified in its Charter)

+86 21 6163 2588

+1 857 706 2604

(Registrant’s Telephone Number, Including Area Code)

Securities registered pursuant to Section 12(b) of the Act:

*Included in connection with the registration of the American Depositary Shares with the Securities and Exchange Commission. The ordinary shares are not registered or listed for trading in the United States but are listed for trading on the Stock Exchange of Hong Kong Limited.

Securities registered pursuant to Section 12(g) of the Act: None

Indicate by check mark if the registrant is a well-known seasoned issuer, as defined in Rule 405 of the Securities Act. Yes x Noo

Indicate by check mark if the registrant is not required to file reports pursuant to Section 13 or Section 15(d) of the Act. Yeso No x

Indicate by check mark whether the registrant: (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the registrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90 days. Yes x Noo

Indicate by check mark whether the registrant has submitted electronically every Interactive Data File required to be submitted pursuant to Rule 405 of Regulation S-T during the preceding 12 months (or for such shorter period that the registrant was required to submit such files). Yes x Noo

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, a smaller reporting company, or an emerging growth company. See the definitions of “large accelerated filer,” “accelerated filer,” “smaller reporting company,” and “emerging growth company” in Rule 12b-2 of the Exchange Act.:

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. o

Indicate by check mark whether the registrant has filed a report on and attestation to its management’s assessment of the effectiveness of its internal control over financial reporting under Section 404(b) of the Sarbanes-Oxley Act (15 U.S.C. 7262(b)) by the registered public accounting firm that prepared or issued its audit report. x

If securities are registered pursuant to Section 12(b) of the Act, indicate by check mark whether the financial statements of the registrant included in the filing reflect the correction of an error to previously issued financial statements. o

Indicate by check mark whether any of those error corrections are restatements that required a recovery analysis of incentive-based compensation received by any of the registrant’s executive officers during the relevant recovery period pursuant to §240.10D-1(b). o

Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Exchange Act). Yeso Nox

As of June 30, 2025, the last business day of the registrant’s most recently completed second fiscal quarter, the aggregate market value of the ordinary shares, including in the form of American Depositary Shares (“ADSs”), each representing ten ordinary shares, held by non-affiliates of the registrant was approximately $3.8 billion, based upon the closing price of the registrant’s ADSs on the Nasdaq Global Market of $34.97 on June 30, 2025.

As of February 20, 2026,1,106,407,390 ordinary shares, par value $0.000006 per share, were outstanding, of which 307,140,690 ordinary shares were held in the form of ADSs.

DOCUMENTS INCORPORATED BY REFERENCE

The registrant intends to file a definitive proxy statement pursuant to Regulation 14A within 120 days of the end of the fiscal year ended December 31, 2025. Portions of such definitive proxy statement are incorporated by reference into Part III of this Annual Report on Form 10-K.

2025 Annual Report on Form 10-K

TABLE OF CONTENTS

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Forward-Looking Statements

This report contains certain forward-looking statements, including statements relating to our strategy and plans; potential of and expectations for our business, commercial products, and pipeline programs; the market for our commercial and pipeline products; capital allocation and investment strategy; clinical development programs and related clinical trials; clinical trial data, data readouts, and presentations; 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 our collaboration partners; the anticipated benefits and potential of investments, collaborations, and business development activities; our profitability and timeline to profitability; and our future financial and operating results. All statements, other than statements of historical fact, included in this report are forward-looking statements, and 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. Forward-looking statements are not guarantees or assurances of future performance. Forward-looking statements are based on our expectations and assumptions as of the date of this report and are subject to inherent uncertainties, risks, and changes in circumstances that may differ materially from those contemplated by the forward-looking statements. We may not actually achieve the plans, carry out the intentions, or meet the expectations or projections disclosed in 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:

• 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 product candidates;

• Any inability of third parties on whom we rely, such as our licensors, CMOs, and others that supply certain of our products and product candidates; CROs that conduct or support some of our pre-clinical and clinical trials; and distributors that sell our commercial products, to successfully carry out their contractual duties or meet expected deadlines;

• Any issues that our Chinese manufacturing facilities may have with operating in conformity with established GMPs and international best practices, and with passing FDA, NMPA, and EMA inspections;

• Any inability to obtain or maintain sufficient patent protection for our products and product candidates;

• 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;

• Significant business disruptions caused by events or developments outside of our control, such as pandemics, international war or conflict, natural disasters or extreme weather events, and other geopolitical events;

• Uncertainties in the Chinese legal system, including with respect to the anti-corruption enforcement efforts in mainland China and those addressing espionage, protection of and transfer restrictions on data, including personal information, data processing and security, and cybersecurity, and other future laws and regulations or amendments to such laws and regulations;

• Approval, filing, or procedural requirements imposed by the CSRC or other Chinese regulatory authorities in connection with issuing securities to foreign investors under Chinese law;

• Any violation or liability under the FCPA or Chinese anti-corruption, anti-bribery, and anti-fraud laws;

• Variations in currency exchange rates and restrictions on currency exchange;

• Limitations on the ability of our Chinese subsidiaries to make payments to us;

• Chinese requirements on the ability of residents in mainland China to establish offshore special purpose companies;

• Chinese regulations regarding acquisitions of companies based in mainland China by foreign investors;

• Expiration of, or changes to, financial incentives or discretionary policies granted by local governments in mainland China;

• Restrictions or limitations on the ability of overseas regulators to conduct investigations or collect evidence within mainland China;

• Unfavorable tax consequences to us and our non-Chinese shareholders or ADS holders if we were to be classified as a Chinese resident 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 reputation;

• Delays or obstacles for closing transactions, such as review by the CFIUS in our investments; and

• Any inability to renew our current leases on desirable terms or otherwise locate desirable alternatives for our leased properties.

For more information on these factors and other risks and uncertainties that may affect our business, see Risk Factors. These factors should not be construed as exhaustive and should be read with the other cautionary statements and information in this report. Forward-looking statements are based on our management’s beliefs and assumptions and information currently available to our management. These statements, like all statements in this report, speak only as of their date. We anticipate that subsequent events and developments will cause our expectations and assumptions to change, and we undertake no obligation to update or revise any forward-looking statements, whether as a result of new information, future events, or otherwise, except as may be required by law. These forward-looking statements should not be relied upon as representing our views as of any date subsequent to the date of this report.

Usage of Terms

Throughout this report, we use certain acronyms and terms that are defined in the Glossary. Unless the context requires otherwise, 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 (Zhejiang) 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.

We own various trademarks, including various forms of the Zai Lab brand (in English and Chinese), as well as several domain names that incorporate such trademarks. Trademarks and trade names 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 with limited liability in March 2013. We have substantial operations in mainland China. Below is a summary of certain risks related to our Chinese operations. For more information on material risks that may affect our business and securities, see Risk Factors.

Zai Lab Limited is not a Chinese operating company, but a holding company incorporated in the Cayman Islands.

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. The Chinese government regulates Chinese companies raising capital outside of mainland China, including through 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. 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 political and economic policies of the Chinese government, relations between mainland China and the United States, or applicable Chinese or U.S. laws and regulations, that may materially and adversely affect our business, financial condition, and results of operations.

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 political and economic policies of the Chinese government, relations between mainland China and the United States, or applicable Chinese or U.S. laws and 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 and evolving laws and regulations, including those addressing espionage, protection of and transfer restrictions on data, including personal information, data processing and security, and cybersecurity, 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, and results of operations.

We are or may be required to obtain certain permissions from Chinese authorities to operate in mainland China, transfer certain scientific data, and issue our securities to foreign investors.

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 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. To date, 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 CAC for transfers out of mainland China of certain important or personal data, or obtain prior clearance or approval from the 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, which may have a material adverse effect on our business prospects, financial condition, results of operations, and the price of our securities.

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 the Trial Measures and five supporting guidelines, which require us 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. For example, we were required to file with the CSRC with respect to the registered offering of our ADSs in November 2024. If we are not able to complete the necessary filings for future securities offerings, our ability to raise capital may be adversely affected.