Vaxcyte Advances Pneumococcal Vaccine Candidate with Phase 3 Enrollment Complete
Event summary
- Vaxcyte has completed enrollment for Phase 3 trials (OPUS-1 and OPUS-2) of its 31-valent pneumococcal conjugate vaccine (VAX-31) for adults.
- OPUS-1 will compare VAX-31 to existing standard-of-care vaccines (Capvaxive® and Prevnar 20®) for safety, tolerability, and immunogenicity; topline data expected in Q4 2026.
- OPUS-2 will evaluate concomitant administration of VAX-31 and a seasonal influenza vaccine, with results expected in H1 2027.
- The trials were designed in consultation with the FDA and aim to support a Biologics License Application (BLA) submission.
The big picture
The pneumococcal vaccine market is dominated by Pfizer and Merck, and Vaxcyte’s VAX-31 represents a significant challenge to their established franchises. With a broader serotype coverage, VAX-31 aims to address unmet needs in adult pneumococcal disease prevention, potentially capturing a substantial share of the ~$3 billion annual market. The success of these Phase 3 trials will be a key indicator of Vaxcyte’s ability to disrupt the existing landscape and establish itself as a major player.
What we're watching
- Clinical Outcomes
- The topline data from the OPUS-1 trial in Q4 2026 will be critical in determining whether VAX-31 demonstrates non-inferiority and superiority over existing vaccines, directly impacting its regulatory pathway.
- Regulatory Risk
- The FDA’s assessment of the broader dataset generated by the OPUS trials will be key, as the agency’s expectations for next-generation pneumococcal vaccines may evolve.
- Market Adoption
- The success of the concomitant administration study (OPUS-2) will influence Vaxcyte’s strategy for post-licensure uptake, as combined vaccination schedules are increasingly common.
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