Antengene Announces First Patient Dosed in the Nivolumab Combination Portion of the Clinical Study Evaluating the ERK1/2 Inhibitor ATG-017 in Patients with Advanced Solid Tumors in the United States

- ATG-017 is an oral,potent and selective small molecule ERK1/2 inhibitor.Antengene has exclusiveglobal rights to develop,commercialize,and manufacture ATG-017

- The combination portion of the ERASER study,the first-in-human (FIH) study of ATG-017,was designed toevaluate the safety/tolerability,pharmacokinetics,and preliminary efficacy of ATG-017 combination therapy with nivolumab in patients with advanced solid tumors

- The monotherapy portion of the ERASER study is currently ongoing in Australia while the combination portion will be carried out in parallel in both the U.S. and Australia

SHANGHAI and HONG KONG,July 18,2023 -- 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 thatthe first patient has been dosed in the United States in the combination portion of the Phase I ERASER trial to evaluate ATG-017 plus nivolumab.The objective of the combination segment of the study is to evaluate the safety/tolerability,pharmacokinetics,and preliminary efficacy of ATG-017 combination therapy with nivolumab in patients with advanced solid tumors.

ATG-017 is an oral,potent,and selective inhibitor of extracellular signal-regulated protein kinase 1 and 2 (ERK1/2). Nivolumab is a human programmed death receptor-1 (PD-1) blocking antibody that binds to the PD-1 receptor expressed on activated T-cells.The clinical collaboration between Antengene and Bristol Myers Squibb (BMS) to evaluate ATG-017 in combination with nivolumab (the ERASER study) builds on Antengene's preclinicaldata which have demonstrated that the combination of an ERK1/2 inhibitor and an immune checkpoint inhibitor (ICI) worked synergistically to produce improved efficacyin preclinical ICI-resistantin vivomurine models.

"We are pleased that the first patient in the combination cohort of the ERASER study of ATG-017 in the US has been dosed. Meanwhile,the monotherapy segment of the study is progressing well as planned in Australia," saidDr. Amily Zhang,Antengene's Chief Medical Officer. "Based on the the preclinical data of ATG-017 that showed highly specific selectivity and promising activity,as well as synergistic effects in combination with ICIs,we are confident in ATG-017's potential as a best-in-class ERK1/2 inhibitor and look forward to continuing to advance this clinical program of ATG-017."

"Having the first patient dosed in the combination portion of this study of ATG-017 in the U.S. marks another milestone in the development of the drug candidate. We have high hopes for ATG-017,a small molecule ERK1/2 inhibitor with great therapeutic potential in combination with PD-1/PD-L1 blockade or agents targeting signal pathways," said Dr. Jay Mei,Antengene's Founder,Chairman and CEO. "This milestone underscores Antengene's commitment to its global innovation strategies. We will press ahead with this clinical study in efforts to bring another novel,effective and safe treatment option to cancer patients worldwide."

About ATG-017

ATG-017 is an oral,and selective small molecule extracellular signal-regulated kinases 1 and 2 (ERK1/2) inhibitor. ERK1/2 are related protein-serine/threonine kinases that function as terminal kinases in the RAS-MAPK signal transduction cascade. This cascade regulates a large variety of cellular processes,including proliferation. The RAS-MAPK pathway is dysregulated in more than 30% of human cancers with the most frequent alterations being observed in RAS or BRAF genes across multiple tumor types. An ERK inhibitor enables the targeting of both RAS and BRAF mutant diseases.

Antengene presented data at the Society for Immunotherapy in Cancer (SITC) 36th Annual Meeting & Pre-conference Programs in November 2021 detailing compelling preclinical results showing the combination of ATG-017 and an anti-PD-L1 monoclonal antibody (atezolizumab) in an aggressive immune checkpoint resistant murine cancer model rendered "cold" tumors "hot". Antengene is evaluating ATG-017 in the Phase I ERASER study,as monotherapy and in combination with nivolumab,in patients with advanced solid tumors and hematological malignancies in Australia and the U.S.

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 pipeline of 9 oncology assets at various stages going from clinical to commercial,including 6 with global rights,and 3 with rights for the APAC region.To date,Antengene has obtained 29 investigational new drug (IND) approvals in the U.S. and Asia,and submitted 10 new drug applications (NDAs) in multiple Asia Pacific markets,with the NDA for XPOVIO® (selinexor) already approved in Mainland of China,Taiwan China,Hong Kong China,South Korea,Singapore and Australia.

Forward-looking statements

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