X0508 4 2024-04-01 0001704292 Zai Lab Ltd ZLAB 0001725189 Smiley Joshua L C/O ZAI LAB LIMITED 314 MAIN STREET, 4TH FLOOR, SUITE 100 CAMBRIDGE MA 02142 true See Remarks false Stock Options (Right to Buy) 16.72 2024-04-01 4 A 0 197306 0 A 2034-04-01 American Depositary Shares 197306 197306 D Restricted Share Units 2024-04-01 4 A 0 128249 0 A American Depositary Shares 128249 128249 D Each Stock Option is exercisable for one American Depositary Share ("ADS"), which represents ten Ordinary Shares of the issuer. The option vests in equal annual installments over four years beginning on 04/01/2025, the first anniversary of the date of grant, subject to continuous service. Each 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. Each Restricted Share Unit ("RSU") represents a contingent right to receive one ADS, which represents ten Ordinary Shares of the issuer. The RSUs vest in equal annual installments over four years beginning on 04/01/2025, the first anniversary of the date of grant, subject to continuous service. Vested shares will be delivered to the reporting person following vesting. President and Chief Operating Officer /s/ Bruce Blefeld, Attorney-in-Fact 2024-04-03