Antengene Enters into a Global Clinical Collaboration with MSD to Evaluate ATG-037 (CD73 Inhibitor) in Combination with KEYTRUDA® (pembrolizumab)

- ATG-037 is Antengene's oral small molecule CD73 inhibitor; KEYTRUDA® (pembrolizumab) is MSD's anti-PD-1 therapy

- The clinical trial collaboration will focus on evaluating ATG-037 as a monotherapy and in combination with KEYTRUDA® for the treatment of locally advanced or metastatic solid tumors

- The study of ATG-037 monotherapy started enrolling patients in Q2 2022 and will include the combination with KEYTRUDA® in 2023

SHANGHAI and HONG KONG,Dec. 27,2022 --Antengene Corporation Limited ("Antengene" SEHK: 6996.HK),a leading commercial-stage innovative,global biopharmaceutical company dedicated to discovering,developing and commercializing first-in-class and/or best-in-class medicines for hematology and oncology,today announced it has entered into a global clinical collaboration with MSD (Merck & Co.,Inc.,Rahway,NJ,USA) on a multicenter,open-label,Phase I dose-finding study of ATG-037 as a monotherapy and in combination with MSD's anti-PD-1 therapy,KEYTRUDA® (pembrolizumab),in patients with locally advanced or metastatic solid tumors (the STAMINA-001 study).

The primary objective of the STAMINA-001 study is to evaluate the safety and tolerability of ATG-037 as monotherapy and in combination with KEYTRUDA®,to determine the appropriate dose for Phase II studies. Secondary objectives of the study include the characterization of the pharmacology and evaluation of preliminary efficacy of ATG-037. Under the terms of the Agreement,the study will be conducted by Antengene,and MSD will provide KEYTRUDA® for the combination portions of the trial.

ATG-037,is an innovative asset in-licensed from Calithera with global rights and developed in-house by Antengene,has been approved to enter clinical studies in Australia and China,thus becoming the first oral small molecule CD73 inhibitor entering the clinical-stage in China and the wider Asia Pacific region. The patient enrollment for the Phase I study of ATG-037 is currently underway in Australia.

"Antengene believes that cancer treatments involving the rational combination of immuno-oncology drugs and targeted therapies may offer the greatest opportunity for substantial advances in treatment outcomes for patients with cancer," said Dr. Amily Zhang,Antengene's Chief Medical Officer. "The mechanism of action of ATG-037 in inhibiting adenosine-generating CD73 is expected to reverse an immunosuppressed tumor microenvironment,thereby creating potential additive benefit with multiple immuno-oncological approaches. We are very excited to assess the impact of ATG-037 as a monotherapy and in combination with MSD's KEYTRUDA®,and have already begun recruiting patients for the STAMINA-001 study in Australia. We hope this collaboration will generate data that allows us to proceed to later phase studies in patients with a variety of cancers,with potential for significant positive impact on treatment outcomes." continued Dr. Zhang.

"Exploring novel combinations between compounds from our portfolio with immunotherapeutic drugs or drugs with highly targeted mechanisms of action has always been Antengene's top priority towards delivering transformational cancer therapies. We are enthusiastic about the collaboration with MSD because it marks another milestone for us to fulfill our vision of 'Treating Patients Beyond Borders'," said Dr. Jay Mei,Antengene's Founder,Chairman and CEO.

KEYTRUDA® is a registered trademark of Merck Sharp & Dohme LLC.,a subsidiary of Merck & Co.,USA.

About ATG-037

ATG-037 is an orally available,small molecule CD73 inhibitor. CD73 generates adenosine,which leads to immunosuppression in the tumor microenvironment. ATG-037 has demonstrated promising preclinical efficacy as a monotherapy and in combination with immune checkpoint inhibitors (ICIs) and chemotherapy agents. In preclinical studies,the compound has demonstrated the ability to overcome the "hook effect" that has been observed in some anti-CD73 antibodies. In addition,GLP toxicology studies indicate the compound potentially has a wide therapeutic window.

About Antengene

Antengene Corporation Limited ("Antengene",SEHK: 6996.HK) is a leading commercial-stage R&D-driven global biopharmaceutical company focused on the discovery,development,manufacturing and commercialization of innovative first-in-class/best-in-class therapeutics for the treatment of hematologic malignancies and solid tumors,in realizing its vision of "Treating Patients Beyond Borders".

Since 2017,Antengene has built a broad and expanding pipeline of 13 clinical and preclinical assets,of which 10 are global rights assets,and 3 came with rights for Asia Pacific markets including the Greater China region. To date,Antengene has obtained 27 investigational new drug (IND) approvals in the U.S. and Asia,and submitted 9 new drug applications (NDAs) in multiple Asia Pacific markets,with the NDA for XPOVIO® (selinexor) already approved in mainland China,Taiwan,South Korea,Singapore and Australia.

Forward-looking statements

The forward-looking statements made in this article relate only to the events or information as of the date on which the statements are made in this article. Except as required by law,we undertake no obligation to update or revise publicly any forward-looking statements,whether as a result of new information,future events or otherwise,after the date on which the statements are made or to reflect the occurrence of unanticipated events. You should read this article completely and with the understanding that our actual future results or performance may be materially different from what we expect. In this article,statements of,or references to,our intentions or those of any of our Directors or our Company are made as of the date of this article. Any of these intentions may alter in light of future development. For a further discussion of these and other factors that could cause future results to differ materially from any forward-looking statement,see the section titled "Risk Factors" in our periodic reports filed with the Hong Kong Stock Exchange and the other risks and uncertainties described in the Company's Annual Report for year-end December 31,2021,and subsequent filings with the Hong Kong Stock Exchange.

For more information,please contact:

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E-mail: Donald.Lung@antengene.com

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