I-Mab Announces First Patient Dosed in China Phase 2 Combination Trial of Lemzoparlimab with Toripalimab in Patients with Advanced Solid Tumors

SHANGHAI and GAITHERSBURG,Md.,Jan. 18,2022 -- I-Mab (the "Company") (Nasdaq: IMAB),a clinical stage biopharmaceutical company committed to the discovery,development and commercialization of novel biologics,today announced that the first patienthas been dosed in its China phase 2 trial of lemzoparlimab in combination with the PD-1 antibody toripalimab (TUOYI®) in patients with advanced solid tumors. The phase 2 study is designed as a basket trial and could potentially lead to a registrational trial in China.

"We are pleased to initiate the phase 2 trial for the combination of lemzoparlimab and toripalimab in patients with advanced solid tumors in China,and looking forward to accelerating its clinical development," said Dr. Andrew Zhu,President at I-Mab. "We are leveraging our translational medicine findings to select tumors with a higher probability of success for this trial."

Lemzoparlimabis anovel CD47 antibodythatexerts strong anti-tumor activity whileexhibiting minimal binding to red blood cells based on pre-clinical data. It is being evaluated in combination with pembrolizumab (Keytruda®) in advanced solid tumors in the U.S. and in patients with NHL and AML/MDS in other ongoing clinical studies in the U.S. and China. In all clinical trials conducted so far,lemzoparlimab has been administered without a priming dose.

About CD47 and Lemzoparlimab

CD47 is a cell surface protein over-expressed in a wide variety of cancers and can act to protect tumors by delivering a "don't eat me" signal to otherwise tumor-engulfing macrophages. CD47 antibody blocks this signal and enables macrophages to attack tumor cells. However,development of CD47 antibody as a cancer therapy has been hampered by its hematologic side effects,such as severe anemia,caused by natural binding of CD47 antibody to red blood cells. Scientists at I-Mab discovered a novel CD47 antibody,lemzoparlimab,that is designed to target tumor cells while exerting a minimal untoward effect on red blood cells.

Multiple clinical studies are ongoing in both the U.S. and China to explore indications in treating both hematologic malignancies and solid tumors. Lemzoparlimab is being studied in patients with myelodysplastic syndrome (MDS),acute myelocytic leukemia (AML),and advanced solid tumors in combination with chemotherapy and immune checkpoint inhibitors in the U.S. and China. Combined clinical results from these studies could potentially support future registrational trials in China.

In September 2020,I-Mab and AbbVie entered into a global strategic collaboration to develop and commercialize lemzoparlimab. This includes the design and conduct of further clinical trials to evaluate lemzoparlimab in multiple cancers in China and globally. AbbVie has assumed sponsorship of the U.S. study as of April 2021.

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 and autoimmune 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 a fully integrated global 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 visithttp://ir.i-mabbiopharma.comand follow I-Mab onLinkedIn,Twitter,andWeChat.

I-Mab Forward-Looking Statements

This press release contains forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995 and other federal securities laws,including statements regarding data from the lemzoparlimab clinical studies,the potential implications of clinical data for patients,and I-Mab's advancement of,and anticipated clinical development,regulatory milestones,and commercialization of lemzoparlimab. Actual results may differ materially from those indicated in the forward-looking statements as a result of various important factors,including but not limited to I-Mab's ability to demonstrate the safety and efficacy of its drug candidates; the clinical results for its drug candidates,which may not support further development or NDA/BLA approval; the content and timing of decisions made by the relevant regulatory authorities regarding regulatory approval of I-Mab's drug candidates; I-Mab's ability to achieve commercial success for its drug candidates,if approved; I-Mab's ability to obtain and maintain protection of intellectual property for its technology and drugs; I-Mab's reliance on third parties to conduct drug development,manufacturing and other services; I-Mab's limited operating history and I-Mab's ability to obtain additional funding for operations and to complete the development and commercialization of its drug candidates; and the impact of the COVID-19 pandemic on the Company's clinical development,commercial and other operations,as well as those risks more fully discussed in the "Risk Factors" section 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 US 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.

For more information,please contact:

I-Mab

John Long,Chief Financial Officer

E-mail: john.long@i-mabbiopharma.com

Office line: +86 21 6057 8000

Gigi Feng,Chief Communications Officer

E-mail: gigi.feng@i-mabbiopharma.com

Office line: +86 21 6057 5709

Investor Inquiries:

The Piacente Group,Inc.

Emilie Wu

E-mail: emilie@thepiacentegroup.com

Office line: + 86 21 6039 8363

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