● Double-Digit Objective Response Rate (ORR) by Central Review Achieved in Each Cohort and the Bar for Futility was Exceeded in Each Cohort

● Envafolimab Well Tolerated as a Single Agent and in Combination with Yervoy Independent Data Monitoring Committee (IDMC) Recommended Continued Accrual in each Cohort Company Continues to Expect Study to be Fully Enrolled by End of 2023

Suzhou, China, December 15, 2022 - Alphamab Oncology (stock code: 9966.HK) announces that an interim analysis of the safety and efficacy of ENVASARC, a pivotal Phase II registration clinical trial conducted by Alphamab’s partner TRACON Pharmaceuticals in the United States, has been evaluated by the Independent Data Oversight Committee (IDMC) with positive results. The IDMC recommended continued accrual as planned in both cohorts: single agent envafolimab and envafolimab in combination with Yervoy (ipilimumab).

Envafolimab is a single domain Fc fusion PD-L1 antibody independently invented by Alphamab Oncology，which is being studied in the ENVASARC Phase 2 pivotal trial in the U.S. sponsored by Alphamab’s partner TRACON Pharmaceuticals, for the treatment of patients with pleomorphic sarcoma (UPS)/ Myxofibrosarcoma (MFS) who have progressed on prior chemotherapy.

The IDMC reviewed interim safety and efficacy data from 18 patients enrolled into each cohort who completed a minimum of 12 weeks of efficacy evaluations (two on-treatment scans). The double-digit ORR assessed by blinded independent central review in each cohort satisfied the prespecified futility rule. Envafolimab was well tolerated, with only a single related serious adverse event reported in 36 patients. Responses were noted in patients regardless of weight at the 600 mg dose of envafolimab that was instituted following the previous IDMC review of interim safety and efficacy data from patients in the ENVASARC trial treated at the 300 mg dose of envafolimab.

About Envafolimab（KN035）

Envafolimab is a single domain Fc fusion PD-L1 antibody independently invented by Alphamab Oncology, based on its unique design that allows rapid subcutaneous injection, it has advantages of improved safety, convenience in drug administration, and treatment compliance. Patients do not require an intravenous infusion which lowers medical costs. On December 20, 2019, Alphamab Oncology, 3D Medicines, and TRACON Pharmaceuticals reached a strategic cooperation, whereby Alphamab Oncology is responsible for production and quality control, and TRACON is responsible for the clinical development and commercialization of KN035 for the treatment of soft tissue sarcomas in North America.

At present, Envafolimab is being studied in clinical trials in multiple tumor types in China, the United States and Japan, including registration/phase III clinical trials in multiple indications. Envafolimab obtained orphan drug designation from the US FDA for the treatment of advanced biliary tract cancer and soft tissue sarcoma. In November 2021, Envafolimab obtained the market approval by the Chinese National Medical Products Administration for the treatment of MSI-H or dMMR advanced solid tumors. In 2022, Envafolimab was recommended by the CSCO guidelines for diagnosis and treatment of gastric cancer, colorectal cancer, clinical application of immune checkpoint inhibitors, endometrial cancer, cervical cancer and ovarian cancer.

About Alphamab Oncology

Alphamab Oncology is a leading biopharmaceutical company dedicated to the discovery, development manufacturing and commercialization of world-class innovative biotherapeutics for cancer treatment. On December 12, 2019, Alphamab Oncology was listed on the Main Board of Hong Kong Stock Exchange, with the stock code:9966.

We have converged a professional R&D team led by top scientists, and have a complete industrial chain from early research and development of innovative drugs, process development, commercial production to clinical research.

With multiple in-house proprietary platforms of bispecifics, protein engineering and antibody screening, Alphamab Oncology has established a globally competitive and differentiated pipeline which consists of tumor monoclonal antibodies, bispecific antibodies, and antibody-drug conjugates. Among them, 2 varieties were selected into the national special project of " New Drug Development", and 3 varieties were granted 4 orphan drug qualifications by FDA. The world's first subcutaneous PD-L1 inhibitor injection (Envafolimab) has been obtained the market approval by the Chinese National Medical Products Administration. More than 30 clinical studies have been carried out in 6 varieties in China, the United States and Australia, among which 8 studies of 3 varieties have entered the critical clinical stage in China and the United States.

To make cancer manageable and curable，Alphamab Oncology has always been guided by clinical value and patient needs, and focuses on the development of innovative, safe and affordable anti-tumor drugs to benefit patients in China and around the world.

Alphamab Oncology Forward-Looking Statements

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