Biokin's Bispecific ADC Yizekang® (BL-B01D1) Meets Primary Endpoint in Phase III Interim Analysis for HR+/HER2- Breast Cancer

SICHUAN, China — Sichuan Biokin Pharmaceutical Co., Ltd. (688506.SH) said on August 25, 2026 that its pioneering bispecific antibody-drug conjugate, yizekang® (lunkangyilongtuomab / BL-B01D1 / iza-bren), has hit the primary endpoint in a Phase III trial for breast cancer, marking a significant milestone for the world's first and only approved bispecific ADC.

An independent data monitoring committee determined that the drug met the primary endpoint of progression-free survival (PFS) in a pre-specified interim analysis of the BL-B01D1-306 trial. The study evaluates the drug in patients with hormone receptor-positive, HER2-negative (HR+/HER2−) breast cancer — specifically those with unresectable locally advanced, recurrent, or metastatic disease who have failed at least one prior line of chemotherapy.

A First-in-Class Bispecific ADC

Yizekang® is the world's first and only bispecific ADC to receive regulatory approval. Developed in-house by Biokin, the drug targets both EGFR and HER3 — a dual-mechanism approach designed to overcome resistance that has limited earlier-generation therapies.

China's National Medical Products Administration (NMPA) has already approved yizekang® for two indications: nasopharyngeal carcinoma and esophageal squamous cell carcinoma. A new drug application for triple-negative breast cancer has been accepted by the Center for Drug Evaluation (CDE).

A Broad Clinical Pipeline

Biokin has launched more than 40 clinical trials for yizekang® across China and the United States, including 20 Phase III studies — a remarkably aggressive development program for a single asset.

Regulators have taken notice. Seven indications have received breakthrough therapy designations from China's CDE, two have been granted priority review, and one has earned a breakthrough therapy designation from the U.S. Food and Drug Administration.

What Comes Next

The company cautioned that the drug must still complete clinical trials and pass regulatory review before it can be marketed for the HR+/HER2− breast cancer indication. The interim PFS data, while positive, is just one step in a lengthy approval journey.

For Biokin, the Phase III readout underscores the potential of its bispecific ADC platform — and raises the stakes as the company pushes toward approvals across multiple tumor types on two continents.