Merck’s CAPVAXIVE® Shows Positive Phase 3 Results In High-Risk Children And Adolescents

Merck, known as MSD outside the U.S. and Canada, announced positive Phase 3 STRIDE-13 results for CAPVAXIVE® (Pneumococcal 21-valent Conjugate Vaccine) at the 6th ESCMID Conference on Vaccines in Lisbon, Portugal. The study evaluated safety, tolerability, and immunogenicity in children and adolescents aged 2 to <18 years with chronic conditions that increase their risk for pneumococcal disease.

“Children and adolescents living with chronic medical conditions are at increased risk of pneumococcal disease and offering them additional protection is essential. Results from STRIDE-13 demonstrate the potential of CAPVAXIVE to deliver protection for these vulnerable populations, who may benefit from additional pneumococcal disease coverage by including serotypes not contained in other approved pneumococcal infant regimens,” said Dr. Rotem Lapidot, chief of Pediatric Infectious Diseases at Rambam Health Care Campus and investigator, STRIDE-13 trial. 

The trial demonstrated that CAPVAXIVE induced immune responses against all 21 serotypes, meeting the key secondary endpoint. It was noninferior to PPSV23 for the 12 shared serotypes and superior for the nine unique serotypes included only in CAPVAXIVE. Safety outcomes were comparable between CAPVAXIVE and PPSV23, with no unexpected safety signals.

“While CAPVAXIVE was designed to specifically cover the serotypes that cause the majority of invasive pneumococcal disease (IPD) cases in adults, findings from STRIDE-13 underscore its added potential to help protect children and adolescents who are at an increased risk. We are encouraged by the safety and immunogenicity data presented at the 6th ESCMID Conference on Vaccines, which underpin our commitment to ensuring infants and adults have access to protection against invasive pneumococcal disease,” said Dr. Paula Annunziato, senior vice president, infectious diseases and vaccines, Global Clinical Development, Merck Research Laboratories. 

CAPVAXIVE is already approved in the U.S., EU, Japan, and other countries for adults 18 and older. It is designed to broaden protection, covering approximately 84% of invasive pneumococcal disease (IPD) cases in adults ≥50 years, compared to ~52% with PCV20. In high-risk children and adolescents, CAPVAXIVE could protect against ~78% of IPD cases, including 11 unique serotypes accounting for ~34% of cases.

The STRIDE-13 data represent the final readout of Merck’s Phase 3 STRIDE program, which will be submitted to global regulators to potentially expand CAPVAXIVE’s indication to younger at-risk populations.