Vaxcyte (NASDAQ:PCVX) executives used a presentation at an annual biotech summit to highlight progress across the company’s pneumococcal conjugate vaccine (PCV) pipeline, with a particular focus on its 31-valent candidate, VAX-31, and the Phase 3 adult program now underway.
Focus on pneumococcal conjugate vaccines and broader coverage
Chief Executive Officer Grant Pickering said Vaxcyte has become known for its PCV franchise, which he described as the company’s “headliner.” Pickering emphasized that pneumococcal disease remains a significant cause of illness despite the impact of existing vaccines, and argued that today’s technologies have been constrained by limitations in how the vaccines are constructed.
According to Pickering, current manufacturers have said they cannot effectively go beyond 20 or 21 serotypes. He said Vaxcyte’s approach allows it to surpass that ceiling, and that the company’s VAX-31 adult data has already shown what he called the best results generated in the class, with an infant readout still pending.
Adult opportunity and ex-U.S. market development
Pickering described the PCV segment as an $8 billion market that could expand as adult vaccination increases. President and CFO Andrew Guggenhime added that adult pneumococcal vaccination has historically been dominated by the U.S., but said that is changing as more countries recommend broader adult vaccination.
Guggenhime said recent reported results from CAPVAXIVE and Pfizer show “significant growth ex-U.S.” and argued that Vaxcyte could benefit from market development already underway. He also noted the company recently hired its first chief commercial officer, Mike Mullette, to help assess international strategy.
Guggenhime said Vaxcyte is still determining which markets it may commercialize on its own versus where it might partner, particularly given the scope of a global infant opportunity.
Phase 3 program: OPUS-1 and supporting studies
Pickering said Vaxcyte has launched a Phase 3 program for VAX-31 following Phase 2 results that, in his view, differed from historical experience in the class by increasing coverage while also improving immune responses. He said the Phase 3 package was designed in close consultation with the FDA.
He described the pivotal trial, OPUS-1, as a 4,000-subject study in adults aged 50 and older. The study will compare VAX-31 against both current standards of care—Prevnar 20 and Merck’s CAPVAXIVE—aiming to demonstrate non-inferiority for overlapping serotypes and superiority for serotypes not included in comparator vaccines.
Pickering said the FDA and industry have been moving toward a higher non-inferiority standard in adults. He noted Vaxcyte agreed to a stricter margin than has been used historically, and said the company believes its Phase 2 data supports that approach.
Beyond the pivotal study, Pickering and Guggenhime outlined additional Phase 3 efforts, including:
- A concomitant administration study pairing VAX-31 with influenza vaccines, reflecting common pharmacy vaccination practices.
- A prior-vaccination (boosting) study launched “yesterday,” designed to evaluate responses in adults who previously received a lower-valent pneumococcal vaccine, with the goal of supporting a “catch-up” recommendation.
- A manufacturing consistency study planned as part of the filing package.
Pickering said the predictability of the PCV class has historically been high, stating that PCVs with successful Phase 2 data have gone on to succeed in Phase 3 and receive approval.
Competitive landscape and trial comparisons
Pickering contrasted the coverage profiles of Prevnar 20 and CAPVAXIVE, describing CAPVAXIVE’s strategy as shifting toward more recently circulating serotypes at the expense of older serotypes included in earlier vaccines. He said that difference in coverage contributed to recommendations that allow use of either vaccine rather than selecting one outright.
He also cited CAPVAXIVE’s early commercial traction, saying it has sold over $750 million in its first full year and that its market share appears to be approaching 40% to 45%. He suggested CAPVAXIVE could become the market leader by the time VAX-31 launches.
Pickering said VAX-31 is designed to cover both older and newer serotypes, offering what he described as a more comprehensive single option. He also detailed the analytical plan for OPUS-1, explaining that for serotypes shared among all three vaccines, Vaxcyte plans to meet non-inferiority versus at least one comparator, with additional head-to-head analyses for serotypes shared with only one of the marketed vaccines.
Infant program: VAX-24 learnings and VAX-31 expectations
Turning to pediatrics, Pickering said Vaxcyte received Phase 2 results last year from its 24-valent candidate, VAX-24, and expects Phase 2 data for VAX-31 in infants next year. He said VAX-24 appeared “approvable” based on its profile versus Prevnar 20 and that VAX-31 could provide a substantial coverage improvement, potentially increasing coverage from around 60% to the “ninetieth sort of percent” range.
Pickering said VAX-24 showed improved immune responses for circulating serotypes included in Prevnar 20, while some non-inferiority “misses” occurred in serotypes not circulating at meaningful rates. He said Vaxcyte is testing higher doses in VAX-31 in hopes of improving immune responses and reducing misses.
On outcomes studies, Pickering said the adult Phase 3 program aligns with the approach used for currently marketed adult PCVs, with post-approval surveillance planned to confirm real-world effectiveness. For infants, he said the company has not yet held an end-of-Phase 2 discussion, but expected a similar framework could apply.
He also discussed the possibility of an otitis media outcomes study, describing VAX-31 as covering 92% of typed acute otitis media, compared with Prevnar 20 coverage that he said is “two- to three-fold lower.” Pickering argued this could make an outcomes trial feasible in a reasonable timeframe and cost, while potentially demonstrating meaningful prevention of downstream infections in children.
To close, Guggenhime said that following a financing that closed “a little over a week” prior to the event, the company has over $3 billion in cash on a pro forma basis. He said the capital positions Vaxcyte to reach multiple milestones, including a planned biologics license application (BLA) submission for adult VAX-31 by the end of next year and a targeted approval and launch in 2028.
About Vaxcyte (NASDAQ:PCVX)
Vaxcyte, Inc (NASDAQ: PCVX) is a clinical-stage biotechnology company focused on developing a new generation of preventive vaccines aimed at combating serious bacterial diseases. Headquartered in San Carlos, California, Vaxcyte leverages proprietary conjugation technologies to design and manufacture multivalent vaccines targeting pathogens for which there remain significant unmet medical needs. The company’s platform is intended to streamline the production of conjugate vaccines by improving antigen presentation and broadening strain coverage compared with conventional approaches.
Vaxcyte’s lead candidate, VAX-24, is a 24-valent pneumococcal conjugate vaccine designed to protect against 24 serotypes of Streptococcus pneumoniae.
