Truist Securities called pumitamig’s data on Monday “very reassuring,” given the consistency between its performance in Chinese and global patient populations.
Bristol Myers Squibb and BioNTech’s investigational bispecific BNT327, also known as pumitamig, achieved high response and disease control rates in a Phase II study of small cell lung cancer, marking the first-ever global data for the anti-PD-L1/VEGF therapy.
Pumitamig elicited a confirmed overall response rate (ORR) of 76.3% at the Aug. 7 data cutoff. The results, presented Monday at the 2025 World Conference on Lung Cancer, come from 38 evaluable patients who had extensive-stage small cell lung cancer. The bispecific antibody was administered alongside standard-of-care chemotherapy, achieving a 100% disease control rate.
BioNTech was up 2% before the opening bell on Tuesday, while BMS was trading largely flat.
In a note to investors on Monday, Truist Securities said they found this readout “very reassuring” given that it “confirmed the treatment effect seen in China” in a global patient population. BMS and BioNTech did not present geographically disaggregated figures on Monday, but a China readout in March at the 2025 European Lung Cancer Congress touted a confirmed ORR rate of 85.4% and a disease control rate of 97.9%.
On Monday, BioNTech and BMS additionally reported 56.7% tumor shrinkage, with nearly 90% of participants seeing early shrinkage. Median progression-free survival was 6.8 months, while overall survival data were not yet mature at the time of the readout.
In February, BioNTech launched a global Phase III study for pumitamig, dubbed ROSETTA-LUNG01, designed to evaluate the bispecific antibody plus chemotherapy as a first-line option for extensive-stage small lung cancer. That trial is expected to complete in September 2029.
With ROSETTA-LUNG-01, BMS and BioNTech “are leading the race among the PD-(L)1 x VEGF bispecifics in SCLC,” Truist wrote on Monday. The analyst firm anticipates a launch in 2028, potentially unlocking a $1.4-billion revenue opportunities for the partners.
By blocking both PD-L1 and VEGF, pumitamig addresses two fundamental cancer pathways: It prevents cancer cells from evading the immune response, blocking checkpoint inhibition via PD-L1, while also suppressing the formation of new blood vessels through VEGF-directed growth, that would otherwise sustain the tumor. The investigational bispecific was originally developed by Biotheus, which BioNTech acquired in November 2024 for $800 million upfront and up to $150 million in milestones. Then, in June this year, BMS put $11 billion on the line to jointly develop the asset.
Monday’s readout follows a similar PD-L1/VEGF presentation by Summit Therapeutics, which on Sunday reported overall survival data for its own bispecific ivonescimab, in non-small cell lung cancer, pointing to better outcomes in Asian patients versus those in Western countries. This geographic discrepancy, as well as missing significance in overall survival outcomes, makes ivonescimab’s regulatory prospects “uncertain,” Truist wrote in a separate note on Monday.
