I-Mab Announces Share Purchase Plans by the Company and the Senior Management

GAITHERSBURG,Md. and SHANGHAI,Aug. 23,2022 -- I-Mab ("I-Mab" or the "Company") (Nasdaq: IMAB),a clinical-stage biopharmaceutical company committed to the discovery,development,and commercialization of novel biologics,today announced that it plans to implement share repurchases pursuant to the share repurchase program previously authorized by its Board of Directors. On the same day,the Company was also informed by Dr. Jingwu Zang,Chairman and Acting Chief Executive Officer of the Company,and other members of senior management of their intention to use personal funds to purchase the Company's American Depositary Shares (the "ADSs") on the open market. Under the share purchase plans,the Company and the senior management may purchase up to US$40 million of ADSs in aggregate.

The timing and dollar amount of share repurchase and share purchase transactions will be subject to the applicable U.S. Securities and Exchange Commission rule requirements. The Company's Board of Directors will review the implementation of share repurchases periodically,and may authorize adjustment of its terms and size.

About I-Mab

I-Mab (Nasdaq: IMAB) is an innovation-driven global biopharma company focused on the discovery,development and commercialization of novel and highly differentiated biologics for immuno-oncology diseases. The Company's mission is to bring transformational medicines to patients around the world through innovation. I-Mab's globally competitive pipeline of more than 20 clinical and preclinical-stage drug candidates is driven by its internal discovery and global partnerships for in-licensing,based on the Company's Fast-to-Proof-of-Concept and Fast-to-Market development strategies. The Company is progressing from a clinical-stage biotech company into an innovative global specialty biopharmaceutical company with cutting-edge R&D capabilities,a world-class GMP manufacturing facility,and commercial capability. I-Mab has established its global footprint in Shanghai (headquarters),Beijing,Hangzhou,Guangzhou,Lishui and Hong Kong in China,and Maryland and San Diego in the United States. For more information,please visit http://www.i-mabbiopharma.com and follow I-Mab on LinkedIn,Twitter,and WeChat.

Forward Looking Statements

This press release includes certain disclosures which contain "forward-looking statements." These statements are made under the "safe harbor" within the meaning provisions of the U.S. Private Securities Litigation Reform Act of 1995 and other federal securities laws. You can identify forward-looking statements by terminology such as "will," "expects," "anticipates," "future," "intends," "plans," "believes," "estimates," "confident" and similar statements. Statements that are not historical facts,including statements about I-Mab's beliefs and expectations,management's intention to purchase shares,the expected plan and the amount of the shares to be purchased are forward-looking statements. Forward-looking statements involve inherent risks and uncertainties. Actual results may differ materially from those contemplated by the forward-looking statements as a result of various important factors. Those factors and risks are more fully discussed in I-Mab's most recent annual report on Form 20-F,as well as discussions of potential risks,uncertainties,and other important factors in I-Mab's subsequent filings with the U.S. Securities and Exchange Commission. All forward-looking statements are based on information currently available to I-Mab,and I-Mab undertakes no obligation to publicly 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. Any purchase under the Program and by the shareholders will be made depend upon market pricing and conditions,business,legal,accounting and other considerations. The press release does not obligate I-Mab or any of its shareholders to acquire any particular number of its ADSs.

I-Mab Contacts

Richard Yeh

Chief Operating Officer

IR@i-mabbiopharma.com

Gigi Feng

Chief Communications Officer

PR@i-mabbiopharma.com

Investor Inquiries

The Piacente Group,Inc.

Emilie Wu

E-mail: emilie@thepiacentegroup.com

Office line: +86 21 6039 8363

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