Bispecific ADC Iza-bren meets both primary endpoints, significantly improving PFS and OS in unresectable or advanced/metastatic triple-negative breast cancer post-taxane failure

CAR-T Digest - August 2020

Weekly Digest - February 2026

24 February 2026: Bispecific ADC Iza-bren meets both primary endpoints, significantly improving PFS and OS in unresectable or advanced/metastatic triple-negative breast cancer post-taxane failure

Sichuan Baili Tianheng Pharmaceutical announced that its EGFR×HER3 bispecific antibody–drug conjugate Iza-bren has achieved both primary endpoints of progression-free survival and overall survival in a Phase 3 clinical trial (BL-B01D1-307) for advanced or metastatic triple-negative breast cancer, marking the third Phase 3 study of this asset to meet its primary endpoint
According to a pre-specified interim analysis conducted by the Independent Data Monitoring Committee, topline data demonstrated that iza-bren significantly prolonged both PFS and OS, representing the first global evidence that a bispecific antibody ADC has achieved dual-positive PFS and OS results in this treatment setting
The company is actively advancing regulatory engagement based on these findings, with the New Drug Application for recurrent or metastatic esophageal squamous cell carcinoma already accepted and included in priority review by the Center for Drug Evaluation, and additional indications such as nasopharyngeal carcinoma also progressing
To date, iza-bren has received Breakthrough Therapy designation for multiple indications in China, with one indication included in the U.S. FDA Breakthrough Therapy program and is being evaluated in more than 40 clinical trials across China and the United States covering various tumor types
While these milestones underscore Iza-bren’s position as a first-in-class bispecific ADC advancing through late-stage development, the company noted that drug development remains subject to regulatory review and inherent risks, and commercialization will depend on completion of required approval processes in accordance with national regulations