Pfizer Inc. (PFE): 25-Valent PCV Phase 2 Infant Data Look Strong

Goldman Sachs comments on Pfizer's detailed Phase 2 results for its 25-valent pneumococcal conjugate vaccine candidate PF-07872412 in infants, presented at IDWeek 2026. In the firm's view the data look strong: post Dose 4, all 20 shared PCV20 serotypes met the historical 2-fold non-inferiority criterion, and PFE's modeling predicts that >=22/25 serotypes would meet the more stringent 1.5-fold criterion in a large Phase 3 trial; 25vPnC also elicited an enhanced immune response against serotype 3, and PFE has initiated the Phase 3 program. The report notes that Pfizer's Prevnar franchise is under pressure, currently in the adult market from the recent entry of MRK's Capvaxive and from the anticipated future entry of Vaxcyte's VAX-31. This weekend's data are a step toward defending the larger infant market, currently dominated by Prevnar20, where Vaxcyte will have Phase 2 data for VAX-31 in 1H27;