Biokin's Bispecific ADC Shows Promise in Phase 3 Cancer Trial, Boosting BMS Partnership

Biokin, a Chinese biopharmaceutical company, has announced positive topline results from a phase 3 trial of its bispecific antibody-drug conjugate (ADC), izalontamab brengitecan (iza-bren). This development marks a significant milestone for both Biokin and its partner Bristol Myers Squibb (BMS), who secured ex-China rights to the compound in a lucrative deal last year.

Phase 3 Trial Success

The phase 3 trial, conducted by Biokin's subsidiary Baili Pharmaceutical, focused on patients with recurrent or metastatic nasopharyngeal carcinoma who had previously received at least two lines of chemotherapy after treatment with a PD-1/L1 antibody. While specific data have not yet been disclosed, Biokin reported that the study met at least one of its primary endpoints, which included objective response rate and overall survival.

The trial compared iza-bren to the physician's choice of chemotherapy, potentially positioning the ADC as a new treatment option for this difficult-to-treat patient population. This positive outcome not only validates Biokin's approach but also strengthens the value of BMS's investment in the compound.

BMS Partnership and Future Directions

In 2023, BMS entered into a partnership with Biokin, paying $800 million upfront as part of a deal worth up to $8.4 billion for the ex-China rights to iza-bren. The bispecific ADC is designed to engage EGFR and HER3 receptors, which are involved in the survival and proliferation of epithelial tumors, and deliver a cytotoxic payload to cells expressing these proteins.

While Biokin's trial focused on nasopharyngeal carcinoma, BMS has set its sights on triple-negative breast cancer as the lead indication for iza-bren. A phase 2/3 trial in this indication is scheduled to begin this month, highlighting the compound's potential across multiple tumor types. Baili Pharmaceutical is also exploring iza-bren's efficacy in various other cancers, including biliary tract, kidney, liver, lung, and ovarian cancers.

Competitive Landscape

The success of iza-bren comes amid growing interest in EGFRxHER3 ADCs within the pharmaceutical industry. Several companies are advancing similar compounds through various stages of development:

• Duality Biotherapeutics and Avenzo Therapeutics received FDA clearance to initiate a phase 1/2 trial of their EGFRxHER3 ADC in May.
• Biocytogen published preclinical data on a candidate last year.
• CStone Pharmaceuticals shared preclinical data on their contender in May.

This competitive landscape underscores the potential of bispecific ADCs targeting EGFR and HER3 in oncology and highlights the importance of Biokin and BMS's progress with iza-bren.