Vaxcyte's VAX-31 Meets OPUS-1 Primary Endpoints

The Tip Desk · November 5, 2026 · 4 min read

The clinical-stage vaccine company posted a $297.1 million third-quarter net loss and said pro forma cash reached about $3.4 billion after October offerings.

Vaxcyte, Inc. (PCVX), a clinical-stage vaccine innovation company, said VAX-31, its 31-valent pneumococcal conjugate vaccine candidate, met all prespecified primary endpoints in the OPUS-1 pivotal Phase 3 trial in healthy U.S. adults, and that the results will serve as the cornerstone of a planned Biologics License Application.

The randomized, double-blind, active-controlled study evaluated VAX-31 in 4,047 pneumococcal-naive adults, including 3,572 aged 50 and older and 475 aged 18 to 49. In adults 50 and older, all 28 serotypes shared with Prevnar 20 and/or Capvaxive met noninferiority on opsonophagocytic activity geometric mean ratios, using a lower bound of the 95% confidence interval greater than 0.667. The three serotypes unique to VAX-31 and cross-reactive serotype 20B met a prespecified superiority criterion. The company said VAX-31 was well tolerated, with a safety profile similar to the comparators across all ages studied, and that no serious adverse events were considered related to study vaccines.

In individual comparator analyses, VAX-31 met the noninferiority criterion for 20 of 20 serotypes shared with PCV20 and 17 of 19 shared with PCV21. Versus PCV21, serotypes 3 and 12F did not meet the 0.667 criterion but did meet a historical threshold of 0.5. Given current U.S. epidemiology, the company said the comparison to PCV21 is expected to be a particular focus of FDA review.

Chief Executive Officer Grant Pickering said OPUS-1 inaugurated a more stringent noninferiority standard and that the company believes the results further support VAX-31’s potential best-in-class profile. The company expects to report results from the fully enrolled OPUS-2 and OPUS-3 Phase 3 trials in the first half of 2027 and, together with a manufacturing consistency study, to submit a BLA in the first half of 2028. OPUS-2 had 1,390 participants dosed; OPUS-3 had 752. For the infant indication, topline data from the Phase 2 dose-finding study’s primary series and booster are expected either sequentially or together by the end of the first half of 2027.

For the three months ended September 30, 2026, net loss was $297.1 million, or $1.99 a share, compared with $212.8 million, or $1.56 a share, a year earlier. Research and development expenses were $270.3 million, up from $209.9 million, which the company attributed primarily to higher PCV development and manufacturing costs, VAX-31 OPUS Phase 3 trial expenses, and more R&D personnel. General and administrative expenses were $37.9 million.

Cash, cash equivalents and investments were $2,264.4 million as of September 30, 2026, compared with $2,442.6 million at December 31, 2025. The company said approximately $1.1 billion of net proceeds from October 2026 offerings was not included in that September 30 balance. After those proceeds, pro forma cash, cash equivalents and investments were approximately $3.4 billion.

In October 2026, Vaxcyte completed concurrent underwritten offerings generating $1.15 billion in gross proceeds: $575 million of common stock and pre-funded warrants and $575 million of convertible senior notes bearing 1.50% interest and maturing in October 2032. President and Chief Financial Officer Andrew Guggenhime said the company used the proceeds to strengthen the balance sheet and extend its cash runway, and that it is well positioned to support a potential U.S. commercial launch of VAX-31 for adults, the remaining OPUS studies, the infant Phase 2 study, manufacturing scale-up, and earlier-stage programs including VAX-A1 and VAX-XL.

The Phase 1 study of VAX-A1, a Group A Streptococcus vaccine candidate initiated in June 2026, advanced to Stage 2 after an independent data safety monitoring board review of Stage 1 safety and tolerability. Enrollment is planned to begin with Low and Mid Dose cohorts, with a third vaccination added at those doses and a new Stage 3 for the High Dose cohort. Topline Phase 1 data are expected in the second half of 2027. In September 2026 the company appointed Luis Jodar as chief medical officer and David McAvoy as chief legal officer.