Bristol Myers Squibb (NYSE: BMY) and SystImmune reported that izalontamab brengitecan demonstrated statistically significant improvements in overall survival and progression-free survival in two Phase 3 cancer trials, according to data presented at the American Society of Clinical Oncology Annual Meeting.

The drug, an investigational bispecific antibody-drug conjugate targeting EGFR and HER3, met dual primary endpoints in studies for triple-negative breast cancer and esophageal squamous cell carcinoma.

In the PANKU-Breast02 trial involving 418 patients with advanced triple-negative breast cancer, izalontamab brengitecan showed median overall survival of 15.9 months compared to 12.5 months with physician's choice chemotherapy. Median progression-free survival was 8.5 months versus 3.1 months for chemotherapy. The confirmed objective response rate was 51.7% with izalontamab brengitecan compared to 20.5% with chemotherapy.

The PANKU-Esophagus01 trial studied 497 patients with recurrent or metastatic esophageal squamous cell carcinoma. Median overall survival was 9.8 months with izalontamab brengitecan versus 7.2 months with chemotherapy. Median progression-free survival was 4.2 months compared to 2.0 months for chemotherapy. The objective response rate was 35.3% versus 13.1% for chemotherapy.

The drug showed manageable safety profiles in both studies. Grade 3 or higher treatment-related adverse events were predominantly hematologic toxicities. Interstitial lung disease rates were low across both trials.

China's National Medical Products Administration has accepted a New Drug Application for izalontamab brengitecan for esophageal squamous cell carcinoma treatment and included it in priority review.

The studies were sponsored by Sichuan Biokin Pharmaceutical, SystImmune's parent company, in mainland China. Outside China, the drug is jointly developed by SystImmune and Bristol Myers Squibb under a collaboration agreement.