Vaxcyte, a clinical-stage company that develops vaccines against bacterial diseases, recently announced the completion of enrollment for its phase 1/2 clinical trial. This study will assess VAX-31, a candidate for a 31-valent pneumococcal conjugate vaccine (PCV), aimed at preventing invasive pneumococcal disease (IPD). Vaxcyte anticipates releasing primary data concerning the safety, tolerability, and immune response generated by the vaccine from this study in the third quarter of 2024.
The VAX-31 phase 1/2 clinical study is a randomized, observer-blind, active-controlled, dose-finding study involving 1,015 participants. The study compares three different dosage levels of VAX-31 (low, middle, and high) against Prevnar 20 (PCV20). The goal of this study is to determine the optimal dosage of VAX-31 while ensuring its safety and effectiveness.
“Vaxcyte aims to efficiently create and deliver high-fidelity, broad-spectrum carrier-sparing conjugate vaccines in order to add coverage without compromising overall immune responses by using modern synthetic techniques, including advanced chemistry and the XpressCF cell-free protein synthesis platform,” according to Vaxcyte statement. “Vaxcyte is deploying this approach with VAX-24 and VAX-31, the latter of which has the potential to provide the broadest coverage of any PCV to reach the clinic with approximately 95% coverage of circulating IPD strains in the US adult population.”1
In the initial phase 1 segment of the study, 64 healthy adults aged 50 to 64 received a single injection of VAX-31 at 1 of the 3 dosages, which was then compared to PCV20. This phase focused primarily on evaluating the safety and tolerability of the vaccine. An independent Data Monitoring Committee reviewed these results and endorsed the continuation of the study into phase 2. Participants from phase 1 will also have their immunogenicity assessed, and these findings will be combined with data from phase 2 participants.
