Best-in-Class 24-Valent Pneumococcal Conjugate Vaccine Candidate Identified

Vaxcyte, Inc. today announced the publication of the results from the VAX-24 vaccine candidate's pneumococcal disease (PD) proof-of-concept study in the journal The Lancet Infectious Diseases.

This phase 1/2 clinical trial evaluated the safety, tolerability, and immunogenicity of Vaxcyte's investigational 24-valent, carrier-sparing pneumococcal conjugate vaccine (PCV) compared to the current standard-of-care, Prevnar 20® (PCV20, APEXXNAR), for the prevention of invasive pneumococcal disease (IPD) in healthy adults.

The study results showed that VAX-24 demonstrated a safety and tolerability profile comparable to PCV20 at all doses studied and an immunogenicity profile that met or exceeded established regulatory immunogenicity standards for all 24 serotypes at the conventional 2.2 mcg dose.

"The results from the proof-of-concept study provided the first look at the safety and immunogenicity profile of VAX-24 in adults, giving us confidence in the 2.2 mcg dose we plan to advance into Phase 3," said Dr. Jakub Simon, Chief Medical Officer of Vaxcyte, in a press release on December 4, 2023.

"We look forward to initiating our Phase 3 pivotal, non-inferiority study, designed to further establish the clinical potential of VAX-24, and announcing topline data, which we expect in 2025."

PD is an infection caused by Streptococcus pneumoniae bacteria, says the U.S. CDC.

It can result in IPD, including meningitis and bacteremia, and non-invasive PD, including pneumonia, otitis media, and sinusitis.

People can get pneumococcal disease more than once. A previous pneumococcal infection will not protect you from future infection. Therefore, CDC recommends pneumococcal vaccination even if someone has had pneumococcal disease in the past.

In the United States, approximately 320,000 people get pneumococcal pneumonia each year, which is estimated to result in about 150,000 hospitalizations and 5,000 deaths.

Pneumococci also cause over 50% of all cases of bacterial meningitis in the U.S.

As of December 2023, several approved pneumococcal vaccines are available at clinics and pharmacies in the U.S.