Vaxneuvance met key immunogenicity and safety endpoints in phase III PNEU-PED pivotal trial

In the trial, infants were given a 4-dose regimen of either Vaxneuvance or the licensed 13-valent pneumococcal conjugate vaccine (PCV13) at 2, 4, 6, and 12-15 months of age.

In the PNEU-PED study, primary endpoints demonstrated : i. Vaxneuvance had a safety profile generally comparable to PCV13 following receipt of any vaccine dose. ii. At 30 days following the third dose in the series (PD3), Vaxneuvance was non-inferior to PCV13 for all 13 shared serotypes based on serotype-specific response rates (proportions of individuals achieving the accepted immunoglobulin G (IgG) threshold value of 0.35mcg/mL) and for 12 of the 13 shared serotypes based on serotype-specific IgG geometric mean concentrations (GMCs). The lower bounds of the two-sided 95 percent confidence intervals (CI) for the serotype-specific IgG GMC ratios were greater than 0.5 for 12 shared serotypes; the lower bound was 0.48 for serotype 6A, narrowly missing non-inferiority criteria. iii. At 30 days following the fourth (toddler) dose (PD4), Vaxneuvance was non-inferior to PCV13 for all 13 shared serotypes based on serotype-specific IgG GMCs.

Secondary endpoints demonstrated statistically superior immune responses for Vaxneuvance in comparison to PCV13 for shared serotype 3 and unique serotypes 22F and 33F based on prespecified criteria, as well as non-inferior immune responses to antigens contained in several routinely used pediatric vaccines when administered concomitantly with Vaxneuvance or PCV13.

“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,” said Dr. Roy Baynes, senior vice president and head of global clinical development, chief medical officer, Merck Research Laboratories. “At Merck, our goal is to design pneumococcal vaccines that target strains causing the greatest proportion of disease while maintaining a strong immune response to these serotypes. 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.”

In PNEU-LINK (V114-031), a Phase III study to evaluate the safety and tolerability of Vaxneuvance in healthy infants, Vaxneuvance was generally well-tolerated with a safety profile generally comparable to PCV13 in healthy infants enrolled at 42-90 days of age (n=2409). Full results from the PNEU-PED and PNEU-LINK studies will be presented at an upcoming scientific congress.

There are 100 different types of pneumococcal bacteria, which can affect children differently than adults. Children under the age of 2 are particularly vulnerable to pneumococcal infection, and incidence of invasive pneumococcal disease remains highest in the first year of life. Certain pneumococcal serotypes continue to put children at risk, including serotypes 22F, 33F and 3, which represent more than a quarter of all cases of invasive pneumococcal disease in children under the age of 5.

On July 16, 2021, the FDA approved Vaxneuvance for adults 18 years of age and older for active immunization for the prevention of invasive disease caused by the 15 S. pneumoniae serotypes contained in the vaccine. Plans are on track for submission of a supplemental regulatory licensure application to the FDA for use in children before the end of the year.