X0508 4 2025-05-09 0001704292 Zai Lab Ltd ZLAB 0001731790 Du Ying C/O ZAI LAB LIMITED 314 MAIN STREET, 4TH FLOOR, SUITE 100 CAMBRIDGE MA 02142 true true Chairperson & CEO true American Depositary Shares 2025-05-09 4 M 0 50000 0.6 A 529851 D American Depositary Shares 2025-05-09 4 S 0 46362 29.5803 D 483489 D American Depositary Shares 2025-05-09 4 S 0 3638 30.1645 D 479851 D American Depositary Shares 2025-05-12 4 M 0 50000 0.6 A 529851 D American Depositary Shares 2025-05-12 4 S 0 49384 29.4374 D 480467 D American Depositary Shares 2025-05-12 4 S 0 616 29.9201 D 479851 D Stock Options (Right to Buy) 0.6 2025-05-09 4 M 0 50000 0 D 2025-10-22 American Depositary Shares 50000 342776 D Stock Options (Right to Buy) 0.6 2025-05-12 4 M 0 50000 0 D 2025-10-22 American Depositary Shares 50000 292776 D Each American Depositary Share ("ADS") represents ten Ordinary Shares of the issuer. Our ADSs and Ordinary Shares are fully fungible. For purposes of this Form 4, we are reporting this in terms of ADSs. The transactions reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on November 20, 2024. Reflects a weighted average sale price of $29.5803 per share, at prices ranging from $29.125 to $30.12 per share. The Reporting Person will provide, upon request by the staff of the Securities and Exchange Commission, the Issuer, or a security holder of the Issuer, full information regarding the number of shares sold at each separate price. Reflects a weighted average sale price of $30.1645 per share, at prices ranging from $30.125 to $30.24 per share. The Reporting Person will provide, upon request by the staff of the Securities and Exchange Commission, the Issuer, or a security holder of the Issuer, full information regarding the number of shares sold at each separate price. Reflects a weighted average sale price of $29.4374 per share, at prices ranging from $28.89 to $29.88 per share. The Reporting Person will provide, upon request by the staff of the Securities and Exchange Commission, the Issuer, or a security holder of the Issuer, full information regarding the number of shares sold at each separate price. Reflects a weighted average sale price of $29.9201 per share, at prices ranging from $29.91 to $30.00 per share. The Reporting Person will provide, upon request by the staff of the Securities and Exchange Commission, the Issuer, or a security holder of the Issuer, full information regarding the number of shares sold at each separate price. The Stock Options fully vested as of October 22, 2020. /s/ Bruce Blefeld, Attorney-in-Fact 2025-05-13