November 17, 2025 – Iza-bren, a global first-in-class, new concept EGFR×HER3 bispecific antibody-drug conjugate (ADC) independently developed by Biokin Pharmaceutical, and the only candidate of its kind to have entered Phase III clinical trials, has reached both dual primary endpoints of Progression-Free Survival (PFS) and Overall Survival (OS) in a pre-specified interim analysis. This outcome was determined by the Independent Data Monitoring Committee (iDMC) for the Phase III clinical trial (Study Protocol: BL-B01D1-305) in advanced esophageal squamous cell carcinoma.
This marks the first global Phase III clinical study of an ADC drug in esophageal cancer treatment to report positive results for both PFS and OS. The investigated indication is recurrent or metastatic esophageal squamous cell carcinoma in patients who have failed prior treatment with PD-1/PD-L1 monoclonal antibodies combined with platinum-based chemotherapy.
According to GLOBOCAN 2022 statistics, approximately 511,000 new cases of esophageal cancer are diagnosed globally each year, with 224,000 of those occurring in China, accounting for 43.8% of the global total. China has the highest number of incident cases and deaths from esophageal cancer worldwide. In China, esophageal squamous cell carcinoma comprises over 90% of all esophageal cancer cases, making it the most common pathological type. There is a significant unmet clinical need for effective second-line treatment options after disease progression on first-line immunotherapy combined with chemotherapy.
On July 10, 2025, results from an Ib phase clinical study of iza-bren in patients with advanced esophageal squamous cell carcinoma, led by Professor Shen Lin's team at Peking University Cancer Hospital, were published in the internationally renowned academic journal Nature Medicine. The publication highlighted the encouraging antitumor activity and safety profile of iza-bren. The success of this Phase III clinical study heralds a historic breakthrough for iza-bren, a global first-in-class EGFR×HER3 bispecific ADC, in the treatment of patients with advanced esophageal squamous cell carcinoma.
Notably, this represents the second confirmatory registrational Phase III clinical study for iza-bren to have met its primary endpoint(s). In July 2025, iza-bren met the primary endpoint in a pre-specified interim analysis of its Phase III clinical trial for nasopharyngeal carcinoma. Subsequently, in September 2025, it was included in the Priority Review and Approval List by the Center for Drug Evaluation (CDE) of the National Medical Products Administration (NMPA).
As of November 2025, iza-bren is being evaluated in over 40 clinical studies across various tumor types, conducted in both China and the United States. This robust clinical program includes 10 registrational Phase III studies in China and 3 global pivotal registrational studies. Within these investigations, iza-bren has received significant regulatory recognition: it has been included in the Breakthrough Therapy Designation list by the CDE for seven indications, including non-small cell lung cancer, small cell lung cancer, nasopharyngeal carcinoma, urothelial carcinoma, esophageal cancer, and ovarian cancer. Additionally, one of its indications has been granted Breakthrough Therapy Designation by the U.S. Food and Drug Administration (FDA).
About Iza-bren (BL-B01D1)
Iza-bren (BL-B01D1) is a global first-in-class, new concept EGFR×HER3 bispecific antibody-drug conjugate (ADC) and the only candidate of its kind to have advanced into Phase III clinical trials. As of November 2025, Biokin Pharmaceutical is conducting over 40 clinical trials for iza-bren across various tumor types in both China and the United States. In the U.S., in collaboration with strategic partner Bristol Myers Squibb, the company is jointly conducting a Phase II/III clinical trial for first-line advanced triple-negative breast cancer, a Phase II/III clinical trial for advanced non-small cell lung cancer following EGFR-TKI resistance, and a Phase II/III clinical trial for pretreated advanced metastatic urothelial carcinoma, as well as multiple Phase I/II clinical trials for conditions such as non-small cell lung cancer and advanced solid tumors. In China, 10 Phase III registrational studies targeting different cancer types are underway, among which seven indications have been included in the Breakthrough Therapy Designation list by the Center for Drug Evaluation (CDE) of China's National Medical Products Administration (NMPA). On September 5, 2025, iza-bren was formally included in the CDE's Priority Review procedure, for the indication of previously treated recurrent or metastatic nasopharyngeal carcinoma. As a first-in-class drug, research findings on iza-bren have been presented at major global academic conferences in recent years, including ASCO, ESMO, WCLC, and SABCS. Furthermore, full-length manuscripts have been published in top-tier academic journals such as The Lancet Oncology, Nature Medicine, and the Journal of Clinical Oncology, consistently demonstrating promising efficacy signals and a favorable safety profile.
