Vaxcyte Completes 5,300-Patient Phase 3 Trials, OPUS-1 Topline Data Due Q4 2026
Vaxcyte has fully enrolled approximately 4,000 adults in the OPUS-1 Phase 3 trial and 1,300 participants in OPUS-2 evaluating its 31-valent pneumococcal conjugate vaccine, VAX-31, head-to-head with PCV21 and PCV20. Topline safety and immunogenicity data for OPUS-1 are expected in Q4 2026, with OPUS-2 results in H1 2027.
1. Enrollment Milestones
Vaxcyte announced full enrollment of approximately 4,000 adults in the OPUS-1 pivotal Phase 3 trial and 1,300 adults in the OPUS-2 trial assessing VAX-31 administered alongside a seasonal influenza vaccine. These completions mark key steps toward generating a comprehensive safety, tolerability and immunogenicity dataset for regulatory review.
2. OPUS-1 and OPUS-2 Trial Design
OPUS-1 is a randomized, double-blind, active-controlled trial comparing VAX-31 High Dose with Capvaxive® (PCV21) and Prevnar 20® (PCV20) across adults aged 18–49 and ≥50, assessing immune responses for 31 serotypes. OPUS-2 evaluates concomitant administration of VAX-31 and flu vaccine to mirror real-world use and inform combined safety and immunogenicity profiles.
3. Next Steps and Regulatory Path
Topline immunogenicity and safety results from OPUS-1 are slated for the fourth quarter of 2026, with OPUS-2 and the ongoing OPUS-3 readouts expected in the first half of 2027. Data from these studies will support Vaxcyte’s planned Biologics License Application submission to the FDA for adult pneumococcal disease prevention.