Vaxcyte Doses First Adult in Group A Strep Vaccine Trial

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

Cash, cash equivalents and investments stood at $2,507.7 million as of June 30, 2026, as the company posted a $284.3 million net loss for the quarter.

Vaxcyte, Inc. (PCVX), a clinical-stage vaccine innovation company, announced in June 2026 that the first participant was dosed in a Phase 1, first-in-human study of VAX-A1, an investigational prophylactic vaccine candidate for disease caused by Group A Streptococcus in healthy adults aged 18 to 40.

The company said in May that it expected to initiate the study in mid-2026. All participants enrolled in Stage 1 have received the first of two planned doses. Stage 2 is expected to proceed only after the Data Safety Monitoring Board reviews unblinded Stage 1 safety and tolerability data. All participants will be evaluated for safety through six months after the second dose. Topline data from the Phase 1 study are expected in the second half of 2027.

The randomized, double-blind, placebo-controlled, dose-escalation study’s primary objective is to assess safety and tolerability, with a secondary objective of evaluating initial immunogenicity. Group A Strep remains a major global cause of morbidity and mortality in adults and children and a leading driver of antibiotic use.

The VAX-A1 start did not change the company’s near-term readout calendar for its pneumococcal conjugate vaccine franchise. All three VAX-31 adult Phase 3 OPUS trials remained fully enrolled, with 6,191 adults dosed in total, approximately 3,500 of whom received VAX-31. Enrollment in those studies had already been completed in the prior quarter. OPUS-1, the pivotal noninferiority trial with 4,049 participants dosed, is still expected to report topline safety, tolerability and immunogenicity data in the fourth quarter of 2026. OPUS-2 (1,390 dosed) and OPUS-3 (752 dosed) results are expected in the first half of 2027. Chief Executive Officer Grant Pickering said the company is on track to deliver OPUS-1 topline data in the fourth quarter of this year.

OPUS-1 compares VAX-31 head-to-head with Prevnar 20 and Capvaxive in healthy, pneumococcal-naïve U.S. adults aged 50 and older, with a separate cohort aged 18 to 49. OPUS-2 evaluates VAX-31 given either with or one month after a licensed seasonal influenza vaccine. OPUS-3 evaluates VAX-31 in adults who have previously received pneumococcal vaccination. The company is also planning a manufacturing consistency study as the final Phase 3 study to enable a Biologics License Application. Pickering said OPUS-2 and OPUS-3 results, along with that manufacturing study, would enable the planned BLA submission and potential U.S. commercial launch.

Topline data from the VAX-31 infant Phase 2 dose-finding study, covering both the primary three-dose series and a booster dose, are expected either sequentially or together by the end of the first half of 2027.

Research and development expenses were $267.9 million for the three months ended June 30, 2026, compared with $194.2 million a year earlier. The increase was due primarily to higher development and product manufacturing costs for its PCV programs, including manufacturing to support potential future commercial launches, clinical trial expenses primarily related to the VAX-31 OPUS Phase 3 trials, and higher personnel expenses. General and administrative expenses were $34.9 million, compared with $32.0 million a year earlier, due primarily to higher personnel expenses.

Net loss was $284.3 million for the three months ended June 30, 2026, compared with $166.6 million a year earlier, or $1.97 a share versus $1.22 a share. Interest income was $25.8 million, compared with $31.1 million a year earlier. Other income (expense) was a $7.3 million expense, compared with $28.6 million of other income a year earlier.

Cash, cash equivalents and investments were $2,507.7 million as of June 30, 2026, compared with $2,442.6 million as of December 31, 2025. President and Chief Financial Officer Andrew Guggenhime said the company maintains a strong balance sheet and is well positioned to execute on planned clinical, manufacturing and commercial-readiness milestones.

The board appointed Dr. Moncef Slaoui and Dr. John Markels to replace retiring members Jacks Lee and Dr. Heath Lukatch. Slaoui most recently served as Chief Scientific Advisor of Operation Warp Speed. Markels most recently served as President of Merck Global Vaccines.

Vaxcyte is also advancing VAX-XL, a preclinical next-generation PCV candidate, and VAX-GI, a candidate designed to prevent Shigella.