Vaxcyte VAX-31 Phase 1/2 adult results published in The Lancet

Vaxcyte announced that The Lancet Infectious Diseases published Phase 1/2 data showing VAX-31 was well tolerated and produced robust immune responses in adults 50 and older; the high dose met non-inferiority for 20 shared serotypes and superiority for 11 additional serotypes, and VAX-31 is now being evaluated in the OPUS Phase 3 adult program.

Vaxcyte announced publication in The Lancet Infectious Diseases of Phase 1/2 adult trial results for VAX-31, its 31-valent pneumococcal conjugate vaccine candidate. The study evaluated safety, tolerability and immunogenicity in healthy adults aged 50 years and older and compared VAX-31 to a current standard-of-care vaccine, Prevnar 20. The company reports participants were followed through a six-month evaluation period. Based on the Phase 1/2 findings, VAX-31 is being evaluated in the OPUS Phase 3 adult program. Key findings: - The Lancet Infectious Diseases published the Phase 1/2 adult study results. - The trial involved healthy adults aged 50 and older and compared VAX-31 with Prevnar 20. - VAX-31 was reported as well tolerated with a safety profile similar to PCV20 through six months. - VAX-31 demonstrated robust opsonophagocytic activity (OPA) and IgG immune responses across all 31 serotypes. - The VAX-31 High Dose met or exceeded OPA non-inferiority criteria for the 20 serotypes it shares with PCV20 and met superiority criteria for the 11 incremental serotypes unique to VAX-31. - The High Dose showed greater average OPA responses for 18 of the 20 shared serotypes, with seven serotypes reaching statistically higher responses versus PCV20. Summary: The Phase 1/2 results reported in The Lancet indicate VAX-31 produced strong immune responses and had a safety profile similar to the comparator through six months. The VAX-31 High Dose met predefined non-inferiority and superiority endpoints for shared and incremental serotypes. Further evaluation is underway in the OPUS Phase 3 adult program.