Vaxcyte Pneumococcal Conjugate Vaccines 2024

Vaxcyte Inc.'s carrier-sparing Pneumococcal Conjugate Vaccine (PCV) franchise candidates, including VAX-24, a 24-valent PCV proceeding to Phase 3, and VAX-31, the Company's next-generation 31-valent PCV, are being studied for the prevention of invasive pneumococcal disease (IPD). Vaxcyte is re-engineering the way highly complex vaccines are made through modern synthetic techniques, including advanced chemistry and the XpressCF™ cell-free protein synthesis platform, exclusively licensed from Sutro Biopharma, Inc. Unlike conventional cell-based approaches, the Company's system for producing difficult-to-make proteins and antigens is intended to accelerate its ability to efficient create and deliver high-fidelity vaccines with enhanced immunological benefits disease (PD) is an infection caused by Streptococcus pneumonia  (pneumococcus) bacteria. It can result in IPD, including meningitis and bacteremia, and non-invasive PD, including pneumonia, otitis media, and sinusitis. 

On January 29, 2024, Grant Pickering, Chief Executive Officer and Co-founder of Vaxcyte, said in a press release, "Given the significant progress across our PCV franchise, comprising VAX-24 and VAX-31, we intend to deliver multiple anticipated Phase 3 data readouts over the next few years as we conduct Phase 3 studies and, if those studies are successful, prepare a Biologics License Application submission for either the VAX-24 or VAX-31 adult program." On March 4, 2024, the Company Announced It Expects to Announce Topline Safety, Tolerability, and Immunogenicity Data from Primary Immunization Series by the End of the First Quarter of 2025, Followed by Topline Data from Booster Dose by the End of 2025.

Vaxcyte (Nasdaq: PCVX) is a vaccine innovation company engineering high-fidelity vaccines to protect humankind from the consequences of bacterial diseases. 

VAX-24 Vaccine

VAX-24 is an investigational 24-valent PCV candidate designed to prevent IPD, which can be most serious for infants, young children, older adults, and those with immune deficiencies or certain chronic health conditions. The public health community affirms the need for vaccines that offer broader protection to prevent IPD. VAX-24 is intended to improve the standard-of-care PCVs for children and adults by covering the serotypes responsible for most of the pneumococcal disease currently in circulation. Vaxcyte aims to efficiently create and deliver high-fidelity, broad-spectrum vaccines, such as VAX-24, by using modern synthetic techniques, including advanced chemistry and the XpressCF™ cell-free protein synthesis platform. Vaxcyte is deploying this approach with VAX-24 to add more pneumococcal strains without compromising the overall immune response.

The FDA awarded Breakthrough Therapy Designation on January 5, 2023, and cleared the Company's infant Investigational New Drug application for VAX-24 on February 21, 2023. The first participants were dosed in the Phase 2 study of VAX-24 in healthy infants on March 30, 2023. On April 17, 2023, the Company announced positive clinical trial results. On December 4, 2023, The Lancet Infectious Diseases published - Evaluating the safety, tolerability, and immunogenicity of a VAX-24 in healthy adults aged 18 to 64 years: a phase 1/2, double-masked, dose-finding, active-controlled, randomized clinical trial - that concluded VAX-24 had a safety profile similar to PCV20 at all doses, with the 2·2 μg dose showing increased serotype coverage with decreased carrier suppression.

VAX-31 Vaccine

VAX-31 Adult Program: As of January 29, 2024, all participants were dosed in the Phase 2 portion of the ongoing Phase 1/2 study of VAX-31 in healthy adults. The initiation of the Phase 2 portion occurred after the independent Data Monitoring Committee reviewed the safety and tolerability data from the Phase 1 portion of the study and recommended that the study proceed as planned. This is a randomized, observer-blind, active-controlled, dose-finding study designed to evaluate the safety, tolerability, and immunogenicity of VAX-31 at three dose levels compared to Prevnar 20® (PCV20) in approximately 1,000 healthy adults aged 50 and older. Additional information about the study can be found at NCT06151288.

Vaxcyte Inc. News

January 4, 2024 - Mr. Grant Pickering commented in a press release, "We also received encouraging feedback from the FDA regarding the licensure requirements for VAX-24 in adults. We are fortunate to be afforded these ongoing discussions, given the Breakthrough Therapy designation granted to VAX-24, and expect to seek additional CMC-focused input from regulators as we prepare for and conduct the adult Phase 3 program, which will comprise several studies. With VAX-24 and VAX-31, we are confident in our plans to build a best-in-class PCV franchise that delivers the broadest spectrum of coverage against invasive pneumococcal disease."

July 11, 2023 - Vaxcyte, Inc. announced that the ongoing Phase 2 study of VAX-24 in healthy infants is advancing to the second and final stage of the study. 

Vaxcyte Vaccine Clinical Trials

VAX-24 Infant Phase 2 Study - The VAX-24 infant Phase 2 clinical study, which is now fully enrolled with 802 healthy infants, is a randomized, observer-blind, dose-finding two-stage clinical study evaluating the safety, tolerability, and immunogenicity of VAX-24. The Stage 1 portion of the study evaluated the safety and tolerability of a single injection of VAX-24 at three dose levels (low dose/1.1mcg, middle dose/2.2mcg, mixed dose/2.2mcg or 4.4mcg) and compared to VAXNEUVANCE™ (PCV15), which was the broadest-spectrum PCV at the time of study initiation, in 48 infants. The Stage 2 portion evaluates the safety, tolerability, and immunogenicity of VAX-24 at the same three dose levels and compared to Prevnar 20® (PCV20), currently the broadest-spectrum PCV recommended by the Advisory Committee on Immunization Practices (ACIP), in 754 infants. Participants who received VAX-24 in Stage 1 will continue the standard dosing regimen as part of Stage 2 and will be included in the study's safety, tolerability, and immunogenicity analysis.