Biokin's EGFRxHER3 Bispecific ADC Iza-bren Meets PFS Endpoint in China Phase 3 in EGFR-Mutant NSCLC

Two pages from Sichuan Baili, and the numbers they omit

Announcement 2026-060, dated Aug. 18 and filed by Sichuan Baili Pharmaceutical under stock code 688506, runs to two pages. It states that in trial BL-B01D1-301 the independent data monitoring committee judged the prespecified interim analysis to have met the PFS primary endpoint, that a benefit trend was seen on overall survival, and that the indication is EGFR-sensitizing-mutation locally advanced or metastatic NSCLC after EGFR TKI treatment failure. The company calls this the fourth Phase 3 of the drug to meet its primary endpoint and the first Phase 3 anywhere in which a bispecific ADC has done so in NSCLC. The filing gives no hazard ratio, no median PFS, no patient number and no comparator.

The comparator and the trial name come from Fierce Pharma, which reported that the study, Panku-Lung01, tested iza-bren against platinum-based chemotherapy in advanced EGFR-mutated non-squamous NSCLC after an EGFR TKI, with patients required to have progressed on a third-generation TKI. Endpoints News also covered the result, but its article sits behind a registration wall and was not read for this piece. Fierce recalled a WCLC 2025 Phase 2 subgroup in which chemotherapy-naive patients who had failed a third-generation TKI reached a median PFS of 12.5 months.

Four wins and a growing China label

Iza-bren holds NMPA approval in recurrent or metastatic nasopharyngeal carcinoma and recurrent or metastatic esophageal squamous cell carcinoma, and an NDA in locally advanced or metastatic triple-negative breast cancer has been accepted by the CDE. Across China and the United States the company counts more than 40 clinical trials, 20 of them Phase 3 or Phase 2/3, along with seven indications on the CDE breakthrough list, two in priority review and one FDA Breakthrough Therapy Designation. Fierce dates the two approvals to June and July of this year and notes that the TNBC trial, Panku-Breast02, showed a 40% reduction in risk of death versus physician's choice chemotherapy at ASCO in June.

The drug pairs an EGFR-binding arm and a HER3-binding arm on one antibody carrying a topoisomerase inhibitor payload, as BMS and SystImmune, Biokin's US subsidiary, described it when they signed in December 2023. BMS paid $800 million upfront with up to $500 million in near-term contingent payments and up to $7.1 billion in milestones, for a potential $8.4 billion. The partners co-develop and co-commercialize in the United States, SystImmune keeps mainland China and BMS takes the rest of the world.

The BMS trial this result previews

BMS's global counterpart, Izabright-Lung01, is a Phase 2/3 launched in November 2025 with a readout expected in 2028, according to Fierce, and it likewise requires prior progression on a third-generation EGFR TKI. Fierce also reported that BMS is preparing Izabright-Lung02 in first-line EGFR-mutant disease, combining iza-bren with osimertinib against osimertinib alone or with chemotherapy, after a WCLC 2025 Phase 2 showed a 100% response rate for the combination. SystImmune's newsroom carried no English-language release on the NSCLC result as of Aug. 22, and no BMS statement on the interim analysis was located.

Why This Matters to the APO|APE Reader

A positive China Phase 3 in post-TKI EGFR-mutant NSCLC puts iza-bren into the slot TROP2-directed ADCs have been chasing, and Fierce names Datroway, Trodelvy and sac-TMT as the programs under pressure. The diagnostic question is whether any of these ADCs will need an expression assay. Iza-bren's Phase 3 enrolled on EGFR mutation status alone, and the Aug. 18 filing mentions no HER3 or EGFR protein threshold. If that holds through the global program, the molecular report that already drives first-line TKI selection would also gate the ADC, with no new IHC to validate.