Antengene Announces Submission to the Human Research Ethics Committee in Australia for a Phase I Trial of ATG-018

Developed in-house by internal R&D Team at Antengene,ATG-018 is an orally-available,small molecule ATR inhibitor that targets DNA Damage Response (DDR) pathways.

The Phase I study will evaluate the safety,pharmacology and preliminary efficacy of ATG-018 in patients with advanced solid tumors and hematologic malignancies.

ATG-018 has the potential as the first orally-available,small molecule ATR inhibitor entering clinical development in Australia.

SHANGHAI and HONG KONG,April 27,2022 --Antengene Corporation Limited ("Antengene" SEHK: 6996.HK),a leading innovative,commercial-stage global biopharmaceutical company dedicated to discovering,developing and commercializing first-in-class and/or best-in-class therapeutics in hematology and oncology,today announced that it has filed a clinical trial application with the Human Research Ethics Committee (HREC) in Australia in order to initiate the Phase I ATRIUM trial of ATG-018 in patients with advanced solid tumors and hematologic malignancies.

The primary objective of the study is to evaluate the safety and tolerability of ATG-018 as monotherapy to determine the appropriate dose for Phase IIstudies and assess preliminary efficacy,if available; the secondary objective is to characterize the pharmacology of ATG-018.

ATG-018 is an orally available,potent,selective small molecule ATR inhibitor. ATG-018 inhibits the ATR (ataxia telangiectasia mutated and Rad3-related) kinase,thus limiting cancer cells' ability to repair damaged DNA,in a mechanism also known as synthetic lethality.

Dr. Bo Shan,Chief Scientific Officer of Antengenecommented,"ATG-018,one of Antengene's first in-house programs to reach the clinic,targets the DDR pathway that is deregulated in many cancers. DDR inhibitors represent a promising area of drug development and clinical research in oncology,especially in resistant or advanced diseases. The differentiated profile of ATG-018 may enable it to be used as monotherapy and open the door for novel collaborations and combination regimens that could benefit cancer patients around the world."

Dr. Kevin Lynch,Chief Medical Officer of Antengenecontinued,"Antengene is very excited to submit the ATG-018 Phase I protocol for HREC review,based on its solid preclinical data package including efficacy as a monotherapy in solid tumor models,oral bio-availability and potential biomarkers. The use of biomarker-informed studies may facilitate clinical trial enrollment and provide an additional tool to monitor patients during the trial. As we prepare for the start of this important study,I want to thank all of the investigator sites for their support and enthusiasm,and everyone in Antengene's R&D organization for their dedication in the preparation for this study."

About the ATRIUM Trial

The ATRIUM trial is aPhase I multi-center,open-label,dose finding study of ATG-018 monotherapy in patients with advanced solid tumors or hematologic malignancies. The primary objective of the study is to evaluate the safety and tolerability of ATG-018 and to determine the maximum tolerated dose (MTD) and/or recommended Phase 2 dose (RP2D) and/or biologically effective dose of ATG-018 monotherapy and preliminary efficacy,if available; the secondary objective is to characterize the pharmacology of ATG-018. As a Phase I study,there will be intensive safety monitoring throughout the trial.

About ATG-018

Developed by the internal R&D Team at Antengene,ATG-018 is an oral,selective small molecule inhibitortargeting ataxia telangiectasia and Rad3-related (ATR) kinase. ATR kinase belongs to the phosphoinositide 3 kinase-related family. Inhibiting ATR kinase leads to increased accumulation of single-strand DNA breaks,particularly meaningful for tumor cells which rely on DNA damage repair (DDR). Preclinical studies have demonstrated that ATR inhibitor monotherapy or combination with other drugs (including DDR agents) could be promising therapeutic strategies for solid tumors (including gastric,esophageal,squamous cell carcinoma) and hematologic malignancies (chronic lymphocytic leukemia (CLL),diffuse large B-cell lymphoma [DLBCL] and multiple myeloma [MM]).

According to a preclinical poster presented at AACR 2022,ATG-018 has demonstrated potent in vitro and in vivo monotherapy efficacy in solid tumor/hematologic cancer models with certain homologous recombination deficiencies. These data were supported by a series of genetic alterations that correlated with ATG-018 sensitivity and could be potential predictive biomarkers. Taken together,these data suggest that ATG-018 could be a promising therapeutic agent for patients with such homologous recombination deficiencies/genetic alterations.

ATG-018 is a development stage product candidate and is not approved by any regulatory agency. Antengene has global rights to ATG-018.

About Antengene

Antengene Corporation Limited ("Antengene",SEHK: 6996.HK) is a leading commercial-stage R&D-driven global biopharmaceutical company focused on innovative first-in-class/best-in-class therapeutic medicines for cancer and other life-threatening diseases. Driven by its vision of "Treating Patients Beyond Borders",Antengene aims to provide the most advanced anti-cancer drugs to patients in the Asia Pacific Region and around the world. Since initiating operations in 2017,Antengene has obtained 23 investigational new drug (IND) approvals in the US and in Asia,submitted 6 new drug applications (NDAs) in multiple Asia Pacific markets,with the NDA for selinexor/ATG-010/XPOVIO® in China,South Korea,Singapore and Australia approved. Leveraging partnerships as well as in-house drug discovery,Antengene has built a broad and expanding pipeline of 15 clinical and pre-clinical assets. Antengene has global rights on 10 programs and Asia Pacific rights,including the Greater China region,on 5 programs.

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:

Investor Contacts:

Donald Lung

E-mail: Donald.Lung@antengene.com

Mobile: +86 18420672158

PR Contacts:

Peter Qian

E-mail: Peter.Qian@antengene.com

Mobile: +86 13062747000