BioNTech and Bristol Myers Squibb Present First Global Phase 2 Data for PD-L1xVEGF-A Bispecific Antibody Pumitamig in Advanced Triple-Negative Breast Cancer
BioNTech and Bristol Myers Squibb presented first global Phase 2 interim data for pumitamig (BNT327/BMS986545), a PD-L1xVEGF-A bispecific antibody, in combination with chemotherapy for advanced triple-negative breast cancer (TNBC).
In 39 efficacy-evaluable first- and second-line patients (Cohort 1), pumitamig plus chemo achieved a confirmed objective response rate (cORR) of 61.5%, unconfirmed ORR of 71.8%, disease control rate (DCR) of 92.3%, and a 9-month progression-free survival (PFS) rate of 59.3%.
Efficacy was observed across PD-L1 expression levels (CPS ≥10 and <10), suggesting potential benefit in PD-L1 low or negative tumors where current PD-(L)1 inhibitors have limited activity.
Grade ≥3 treatment-related adverse events occurred in ~38–43% of patients; no pumitamig-related deaths were reported, and the safety profile was considered manageable.
Higher doses of pumitamig correlated with higher response rates (uORR 63.2% at 15 mg/kg, 80.0% at 20 mg/kg), and responses were seen in both first- and second-line settings.
These encouraging Phase 2 results support dose selection and ongoing development in the global Phase 3 ROSETTA BREAST-01 trial in first-line TNBC, planned to start by the end of 2025.