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zlab-20260226false000170429200017042922026-02-262026-02-260001704292dei:AdrMember2026-02-262026-02-260001704292us-gaap:CommonStockMember2026-02-262026-02-26

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): February 26, 2026

ZAI LAB LIMITED

(Exact name of registrant as specified in its charter)

Cayman Islands001-3820598-1144595 (State or other jurisdiction of incorporation)(Commission File Number)(I.R.S. Employer Identification No.)

899 Halei Road Building B, Pudong Shanghai, China 201203

314 Main Street 4th Floor, Suite 100 Cambridge, MA, USA02142 (Address of principal executive offices)(Zip Code)

+86 21 6163 2588 +1 857 706 2604 (Registrant’s Telephone Number, Including Area Code) Not Applicable (Former name or former address, if changed since last report)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

☐Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)

☐ Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)

☐ Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))

☐ Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Securities registered pursuant to Section 12(b) of the Act: Title of each classTrading Symbol(s) Name of each exchange on which registered

American Depositary Shares, each representing 10 Ordinary Shares, par value $0.000006 per shareZLABThe Nasdaq Global Market Ordinary Shares, par value $0.000006 per share*9688The Stock Exchange of Hong Kong Limited

*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 Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter). Emerging growth company ☐ 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. ☐

Item 2.02 Results of Operations and Financial Condition. On February 26, 2026, Zai Lab Limited issued a press release announcing its financial results for the fourth quarter and full year ended December 31, 2025. A copy of the press release is furnished as Exhibit 99.1 to this report and is incorporated herein by reference. The information contained in this report, including Exhibit 99.1 attached hereto, is being furnished and shall not be deemed “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), and shall not be deemed incorporated by reference in any filing under the Securities Act of 1933, as amended, or the Exchange Act, except as expressly set forth by specific reference in such filing.

Item 9.01 Financial Statements and Exhibits. (d) Exhibits

Exhibit No.Description

99.1Press Release issued by Zai Lab Limited on February 26, 2026

104The cover page of this report is formatted in Inline XBRL

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

ZAI LAB LIMITED

By:/s/ Yajing Chen Yajing Chen

Chief Financial Officer

Date: February 26, 2026

zlab-20251106false000170429200017042922025-11-062025-11-060001704292dei:AdrMember2025-11-062025-11-060001704292us-gaap:CommonStockMember2025-11-062025-11-06

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): November 6, 2025

ZAI LAB LIMITED

(Exact name of registrant as specified in its charter)

Cayman Islands001-3820598-1144595 (State or other jurisdiction of incorporation)(Commission File Number)(I.R.S. Employer Identification No.)

899 Halei Road Building B, Pudong Shanghai, China 201203

314 Main Street 4th Floor, Suite 100 Cambridge, MA, USA02142 (Address of principal executive offices)(Zip Code)

+86 21 6163 2588 +1 857 706 2604 (Registrant’s Telephone Number, Including Area Code) Not Applicable (Former name or former address, if changed since last report)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

☐Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)

☐ Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)

☐ Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))

☐ Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Securities registered pursuant to Section 12(b) of the Act: Title of each classTrading Symbol(s) Name of each exchange on which registered

American Depositary Shares, each representing 10 Ordinary Shares, par value $0.000006 per shareZLABThe Nasdaq Global Market Ordinary Shares, par value $0.000006 per share*9688The Stock Exchange of Hong Kong Limited

*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 Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter). Emerging growth company ☐ 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. ☐

Item 2.02 Results of Operations and Financial Condition. On November 6, 2025, Zai Lab Limited issued a press release announcing its financial results for the third quarter of 2025. A copy of the press release is furnished as Exhibit 99.1 to this report and is incorporated herein by reference. The information contained in this report, including Exhibit 99.1 attached hereto, is being furnished and shall not be deemed “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), and shall not be deemed incorporated by reference in any filing under the Securities Act of 1933, as amended, or the Exchange Act, except as expressly set forth by specific reference in such filing.

Item 9.01 Financial Statements and Exhibits. (d) Exhibits

Exhibit No.Description

99.1Press Release issued by Zai Lab Limited on November 6, 2025

104The cover page of this report is formatted in Inline XBRL

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

ZAI LAB LIMITED

By:/s/ Yajing Chen Yajing Chen

Chief Financial Officer

Date: November 6, 2025