Vaxcyte shares surge as pneumococcal vaccine meets main trial goals
PCVX•Vaxcyte said its experimental VAX-31 vaccine met its main goals in a late-stage study of adults aged 50 and older, and shares rose 91% before the bell.
1. Trial results
VAX-31 produced immune responses at least comparable to Pfizer’s Prevnar 20 and Merck’s Capvaxive against 28 strains shared with one or both vaccines. Vaxcyte said responses were stronger against three strains unique to VAX-31 and against strain 20B.
2. Safety and next steps
The vaccine had a consistent safety profile across the age groups studied, with no serious adverse events considered related to the vaccines. Vaxcyte expects results from two other late-stage trials in the first half of 2027 and plans to submit a US marketing application for VAX-31 in the first half of 2028.
