September 3, 2024 - $Vaxcyte (PCVX.US)$shares surged 36.58% to $110.30 in pre-market trading on Tuesday. The company today announced positive topline results from the Phase 1/2 study evaluating the safety, tolerability and immunogenicity of VAX-31, the Company’s 31-valent pneumococcal conjugate vaccine (PCV) candidate designed to prevent invasive pneumococcal disease (IPD), in 1,015 healthy adults aged 50 and older.

VAX-31 generated strong immune responses for all 31 strains of pneumococcus it targets. For the 20 strains it shares with Prevnar 20, VAX-31 met or exceeded immune response criteria at medium and high doses. For the additional 11 strains unique to VAX-31, it met all superiority criteria at all doses.

Based on these promising results, Vaxcyte plans to move VAX-31 to a larger Phase 3 study by mid-2025, with results expected in 2026. The company aims to provide broader protection against pneumococcal disease in adults over 50, addressing an important public health need.

About Vaxcyte

Vaxcyte is a vaccine innovation company engineering high-fidelity vaccines to protect humankind from the consequences of bacterial diseases. The Company is developing broad-spectrum conjugate and novel protein vaccines to prevent or treat bacterial infectious diseases. VAX-31 is a Phase 3-ready 31-valent, carrier-sparing PCV being developed for the prevention of IPD in adults and infants and is the broadest-spectrum PCV candidate in the clinic today. VAX-24, the Company’s 24-valent PCV candidate, is designed to cover more serotypes than any infant PCV on-market and is currently being evaluated in a Phase 2 infant study. Both VAX-31 and VAX-24 are designed to improve upon the standard-of-care PCVs by covering the serotypes in circulation that are responsible for a significant portion of IPD and are associated with high case-fatality rates, antibiotic resistance and meningitis, while maintaining coverage of previously circulating strains that are currently contained through continued vaccination practice.