China-based Zhejiang Medicine Co., Ltd (SHA: 600216) has announced positive results from a Phase II/III clinical study for its sARX788, an anti-HER2 monoclonal antibody-AS269 conjugate, in the treatment of breast cancer. The study, which assessed the drug’s efficacy and safety in HER2-positive local advanced or metastatic breast cancer, reached its pre-set efficacy criteria, demonstrating significant benefits over the control group.
Study Design and Results
The randomized, open, controlled multi-center Phase II/III study used progression-free survival (PFS) as the primary endpoint, as assessed by the Independent Review Committee (IRC). Compared to the control group treated with lapatinib combined with capecitabine, ARX788 significantly prolonged PFS, with a significant statistical difference. These results indicate that ARX788 could offer a more effective treatment option for patients with HER2-positive breast cancer.
Regulatory and Development Updates
Following these positive results, Zhejiang Medicine has filed for communication with the Center for Drug Evaluation (CDE), seeking to terminate the study early and proceed with a New Drug Application (NDA) filing. This move reflects the company’s confidence in the drug’s potential and its readiness to bring this innovative treatment to market.
Global HER2 Targeted Therapies and ARX788’s Position
ARX788, co-developed by US firm Ambrx Biopharma, Inc, is also undergoing a Phase II/III study in HER2-positive advanced metastatic gastric cancer and gastroesophageal junction adenocarcinoma. Zhejiang Medicine secured development and commercialization rights to the drug in China through a licensing deal with Ambrx in June 2013. Globally, available HER2 targeted therapies include Roche’s trastuzumab, Henlius Bio’s Hanquyou (trastuzumab; HLX02), AstraZeneca/Daiichi Sankyo’s fam-trastuzumab deruxtecan, and RemeGen’s disitamab vedotin. Despite Ambrx’s decision to end development of ARX788 in October last year due to various factors, Zhejiang Medicine has continued to invest in the drug’s development, spending RMB 685 million (USD 99.27 million) as of January 31, 2023.-Fineline Info & Tech
