Vaxcyte's VAX-31 Hits All Primary Endpoints in Pivotal Phase 3 OPUS-1 Trial
PCVX has more than doubled off its 52-week low of $37.694 on elevated volume (2.1× avg).
Summary
Vaxcyte's VAX-31 met all primary immunogenicity and safety endpoints in the pivotal OPUS-1 Phase 3 trial, clearing the path for a BLA submission in 1H 2028 and validating its potential best-in-class pneumococcal vaccine profile.
Key Events · Product Development and Regulatory · PCVX
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All Primary Endpoints Met
VAX-31 met all prespecified co-primary immunogenicity endpoints in adults 50+: 11/11 shared serotypes vs PCV20/PCV21, 9/9 vs PCV20-only, 8/8 vs PCV21-only, and 4/4 superiority for unique serotypes and cross-reactive 20B.
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Immunobridging Success
All 32 serotype OPA GMR comparisons met noninferiority (LBCI >0.667) in adults 18-49 compared to adults 50-64, supporting potential label expansion to younger at-risk adults.
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Safety Profile Clean
VAX-31 was well tolerated with a safety profile similar to PCV20 and PCV21. No vaccine-related serious adverse events, no discontinuations due to adverse events, and all 4 deaths assessed as unrelated to vaccination.
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Comparator Nuance vs PCV21
Against PCV21, VAX-31 met noninferiority for 17/19 shared serotypes; serotypes 3 and 12F missed the stricter LBCI >0.667 threshold but met the historical >0.5 threshold — a potential FDA review focus given PCV21's larger adult disease share.
Analysis · PCVX · Life Sciences
Vaxcyte's 31-valent pneumococcal conjugate vaccine candidate VAX-31 met every prespecified co-primary immunogenicity endpoint in the pivotal OPUS-1 Phase 3 trial, positioning the company to file a Biologics License Application in the first half of 2028. The vaccine demonstrated noninferiority to both PCV20 and PCV21 across all shared serotypes and superiority for its three unique serotypes plus cross-reactive 20B, with a safety profile similar to both comparators. The only blemish: serotypes 3 and 12F missed the stricter LBCI >0.667 noninferiority threshold against PCV21 but met the historical >0.5 threshold — a nuance regulators may scrutinize given PCV21's larger share of adult disease coverage. With a combined pneumococcal vaccine market expected to grow from $8.5B to ~$12B by 2030, these results validate Vaxcyte's carrier-sparing platform and support a potential best-in-class profile with 13-36% incremental IPD coverage over standard of care.
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At the time of this filing, PCVX was trading at $87.80 on NASDAQ in the Life Sciences sector, with a market capitalization of approximately $8.4B. The 52-week trading range was $37.69 to $65.00. This filing was assessed with positive market sentiment and an importance score of 9 out of 10.