Zai Lab Limited — Proxy Solicitation & Information Statement 2022

Mar 1, 2022

VOTE BY INTERNET

Before the Meeting - Go to www.proxyvote.com

ZAI LAB LIMITED 4560 JINKE ROAD BLDG. 1, FOURTH FLOOR PUDONG, SHANGHAI, 201210 CHINA

Use the Internet to transmit your voting instructions and for electronic delivery of information up until 8:00 a.m. U.S. Eastern Time / 8:00 p.m Hong Kong Time on March 26, 2022. Have your proxy card in hand when you access the web site and follow the instructions to obtain your records and to create an electronic voting instruction form.

During the Meeting - Go to www.virtualshareholdermeeting.com/ZLAB2022SM or attend in person

You may attend the meeting in person or via the Internet and vote during the meeting. Have the information that is printed in the box marked by the arrow available and follow the instructions. If you wish to attend the meeting in person, please check the meeting materials for any special requirements for meeting attendance.

VOTE BY MAIL

Mark, sign and date your proxy card and return it in the postage-paid envelope we have provided or return it to Vote Processing, c/o Broadridge, 51 Mercedes Way, Edgewood, NY 11717.

TO VOTE, MARK BLOCKS BELOW IN BLUE OR BLACK INK AS FOLLOWS :

D53856-P56193

KEEP THIS PORTION FOR YOUR RECORDS

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THIS PROXY CARD IS VALID ONLY WHEN SIGNED AND DATED. DETACH AND RETURN THIS PORTION ONLY

ZAI LAB LIMITED

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The Board of Directors recommends you vote FOR the following resolution:

For Against Abstain ☐ ☐ ☐

Resolution — Ordinary Resolution

THAT, the subdivision of each issued and unissued ordinary shares of the Company with a par value of US$0.00006 each into 10 ordinary shares with a par value of US$0.000006 each with effect from March 30, 2022, subject to and conditional upon the Listing Committee of The Stock Exchange of Hong Kong Limited granting the listing of, and permission to deal in, (i) the Subdivided Ordinary Shares (as defined below) (ii) any Subdivided Ordinary Shares which may be issued upon exercise of the outstanding share options granted by the Company or any Subdivided Ordinary Shares which may be issued upon vesting of the share awards under the equity incentive plan adopted by the shareholders of the Company on August 21, 2015 (as amended on February 3, 2016 and April 10, 2016) (the “2015 Equity Plan”) and under the equity incentive plan adopted by the shareholders of the Company on August 11, 2017 (the “2017 Equity Plan”), and (iii) any Subdivided Ordinary Shares which may be issued upon the exercise of share options or any Subdivided Ordinary Shares which may be issued upon vesting of the share awards to be granted from time to time under the 2015 Equity Plan and the 2017 Equity Plan, such that the authorized share capital of the Company will be amended:

FROM: US$30,000.00 divided into 500,000,000 shares with a par value of US$0.00006 each;

TO: US$30,000.00 divided into 5,000,000,000 ordinary shares with a par value of US$0.000006 each (the “Subdivided Ordinary Shares”) is hereby approved and adopted.

NOTE: To transact other business as may properly come before the meeting or any adjournment thereof.

Please sign exactly as your name(s) appear(s) hereon. When signing as attorney, executor, administrator, or other fiduciary, please give full title as such. Joint owners should each sign personally. All holders must sign. If a corporation or partnership, please sign in full corporate or partnership name by authorized officer.

Signature [PLEASE SIGN WITHIN BOX] Date Signature (Joint Owners) Date

Important Notice Regarding the Availability of Proxy Materials for the Extraordinary General Meeting: The Notice and Proxy Statement are available at www.proxyvote.com.

• • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • - - - - - - D53857-P56193 ZAI LAB LIMITED Extraordinary General Meeting of Shareholders This proxy is solicited by the Board of Directors

The shareholder(s) hereby appoints Samantha Du (or, should Dr. Du not attend the EGM (as defined below), Mr. F. Ty Edmondson) as proxy, with the power to appoint her substitute, and hereby authorize Dr. Du (or, if applicable, Mr. Edmondson) to represent and to vote, as designated on the reverse side of this ballot, all of the ordinary shares of ZAI LAB LIMITED that the shareholder(s) is entitled to vote at the extraordinary general meeting of the shareholders (the “EGM”) to be held on March 28, 2022 at 8:00 p.m. (Hong Kong Time) / March 28, 2022 at 8:00 a.m. (U.S. Eastern Time), at 4560 Jinke Road, Bldg. 1, Fourth Floor, Pudong, Shanghai, China 201210 or online at www.virtualshareholdermeeting.com/ZLAB2022SM and at any adjournment thereof.

This proxy, when properly executed, will be voted in the manner directed herein. If no such direction is made, this proxy will be voted in accordance with the Board of Directors’ recommendation.

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