Merck’s Pneumococcal Vaccine Meets Key Endpoints in Phase 3 Trial

Merck recently announced that its pneumococcal 15-valent conjugate vaccine, Vaxneuvance, met key immunogenicity and safety endpoints in a Phase 3 clinical trial. 

The PNEU-PED study enrolled infants 42 to 90 days of age. Researchers administered a four-dose regimen of either Vaxneuvance or the licensed 13-valent pneumococcal conjugate vaccine (PCV13) to infants at two, four, six, and 12-15 months of age. 

Overall, Vaxneuvance had a safety profile comparable to PCV13. At 30 days following the third dose, Vaxneuvance was non-inferior to PCV13 for all shared serotypes and 12 of the 13 serotypes. 

At 30 days following the fourth dose, Vaxneuvance was non-inferior to PCV13 for all shared serotypes, based on serotype-specific immunoglobulin G (IgG) geometric mean concentrations (GMCs). 

Secondary endpoints demonstrated superior immune responses for Vaxneuvance compared to PCV13 for shared serotype three and unique serotypes, as well as non-inferior immune responses to antigens contained in routinely used pediatric vaccines. 

“By nature, pneumococcal disease is constantly evolving. Strains of the disease associated with invasiveness cause significant disease burden in children, calling for innovation to help protect this vulnerable population worldwide,” Roy Baynes, MD, senior vice president, head of global clinical development, and chief medical officer of Merck, said in the announcement. 

“With the inclusion of serotypes 22F and 33F, VAXNEUVANCE has the potential to play an important role in the prevention of invasive pneumococcal disease in children,” Baynes continued. 

In an additional Phase 3 study, PNEU-LINK, Vaxneuvance was generally well tolerated with a safety profile comparable to PCV13 in healthy infants enrolled at 42 to 90 days of age.

Merck will present full results from both the PNEU-PED and PNEU-LINK studies in the near future. 

Vaxneuvance is Merck’s 15-valent pneumococcal conjugate vaccine, which consists of multiple purified capsular polysaccharides from S. pneumoniae serotypes. 

The Vaxneuvance Phase 3 clinical development program is comprised of 16 trials investigating the safety, tolerability, and immunogenicity of the vaccine in populations at an increased risk for pneumococcal disease. 

Vaxneuvance is currently under investigation in the pediatric population. 

In July, the FDA approved Vaxneuvance for active immunization to prevent invasive disease caused by streptococcus pneumoniae stereotypes in adults 18 years of age and older. 

The agency approved Vaxneuvance based on data, which showed that immune responses elicited by Vaxneuvance were non-inferior to the currently available PCV13 for the 13 shared serotypes.