24-valent Pneumococcal Vaccine Candidate Advances

Vaxcyte, Inc. today announced that the ongoing Phase 2 study of the VAX-24 pneumococcal conjugate vaccine (PCV) candidate in healthy infants is advancing to the second and final stage.

The Phase 2 study is evaluating the safety, tolerability, and immunogenicity of VAX-24, the Company’s lead, broad-spectrum 24-valent PCV designed to prevent invasive pneumococcal disease.

Vaxcyte’s Phase 2 infant study is being conducted in two stages and compares VAX-24 to the broadest-spectrum standard-of-care PCVs currently available.

Stage 1 of the study evaluated the safety and tolerability of a single injection of VAX-24 at three dose levels in a dose-escalation approach compared to VAXNEUVANCE™ (PCV15) in 48 infants.

The Stage 2 portion is evaluating the safety, tolerability, and immunogenicity of VAX-24 at the same three dose levels compared to PCV20 in approximately 750 infants.

In agreement with the U.S. Food and Drug Administration, Vaxcyte amended the study protocol for Stage 2 and changed the study comparator to PCV20, which is currently the broadest-spectrum PCV recommended by the U.S. CDC's Advisory Committee on Immunization Practices.

Grant Pickering, Chief Executive Officer and Co-Founder of Vaxcyte said in a press release on July 11, 2023, “We designed VAX-24 to deliver broader coverage and improved immune responses, and we look forward to sharing topline data from the primary three-dose immunization series by 2025", followed by topline data from the booster dose approximately nine months later.