Alphamab Oncology Announces the First Patient Dosed in the Phase I Trial of Anti-HER2 bispecific ADC JSKN003

SUZHOU,China,March 16,2023 --Alphamab Oncology (stock code: 9966.HK)announced thatthe first patient has been dosed with 2.1mg/kg in a Phase I clinical study (JSKN003-102) of JSKN003,an Anti-HER2 bispecific ADC.

ADC drugs have the advantages of highly specific targeting of antibody and anti cancer activity of cytotoxin. ADC shave developed rapidly as tumor therapeutics in recent years. Optimizing tumor specificity,linker conjugation chemistry together with improving in vivo stability are the focus of ADC development. JSKN003 is an ADC based on Her2 bispecific antibody KN026. Through enzymatic catalyzed reaction and click chemistry,the payloads are linked to precisely controlled glycan on Fc,when make consistant DAR value close to 4. The better serum stability of JSKN003 ensures much wider therapeutic window. For example,JSKN003 shows better safety profile in preclinical study and comparable tumor killing activity with Enhertu (DS-8201) in both high and low HER2 expression tumor models(CDX+PDX model).

JSKN003 was approved by the Bellberry Human Research Ethics Committee in Australia(JSKN003-001),and the first patient was dosed in September 2022. At present,JSKN003-001 is ongoing smoothly at dose escalation stage,and currently at 5.2mg/Kg level. In October 2022,JSKN003 was approved for Phase I clinical trial by the Center for Drug Evaluation (CDE) of the China National Medical Products Administration. JSKN003-102 is a Phase Ia/Ib clinical trial in Chinese patients with HER2-expressing advanced solid tumors to evaluate the safety,tolerability,pharmacokinetic/pharmacodynamic and anti tumor activity of JSKN003. JSKN003-102 trial and ongoing JSKN003-101 complement with each other,laying the foundation for the global development of JSKN003.

About JSKN003

JSKN003 is an anti-HER2 bispecific antibody-drug conjugate (ADC),which is developed inhouse with proprietary Glycan-specific conjugation platform. JSKN003 targets HER2 and triggers a signal in the tumor cell,which then internalizes the antibody together with the payload. After internalization,the cytotoxic drug is released and kills the tumor cells. Compared other ADC drugs,JSKN003 induce faster and more intense endocytosis,which leads to stronger bystander effect in HER2-expressing tumors. Meanwhile the better serum stability ensures much wider therapeutic window. JSKN003 is currently undergoing phase I clinical research in China and Australia.

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.