Approved 15 months ago as a pneumococcal disease vaccine for adults—and billed as the first shot designed for seniors—Merck’s Capvaxive now has data supporting its potential in children and adolescents.
In a phase 3 study of 882 participants aged 2 through 17 who have completed a primary pediatric pneumococcal vaccination regimen and have one or more chronic medical conditions that put them at an increased risk of the respiratory disorder, Capvaxive made the grade in three key measures.
First, in the primary immunogenicity endpoint, in 12 shared serotypes with Merck’s Pneumovax, Capvaxive’s immune response 30 days after vaccination measured up to the 23-valent polysaccharide pneumococcal shot that has been on the market since 1983. In its nine unique serotypes, Capvaxive showed a superior immune response to Pneumovax.
In a secondary immunogenicity endpoint, Capvaxive generated immune responses to all 21 strains it covers. This was determined by measuring serotype-specific opsonophagocytic activity (OPA) geometric mean titers (GMTs) at 30 days after vaccination.
Thirdly, in the primary safety endpoint, the proportion of participants with adverse events, including events that were systemic and were serious and vaccine-related, were generally comparable between the two groups.
“Children and adolescents living with chronic medical conditions are at increased risk of pneumococcal disease and offering them additional protection is essential,” Rotem Lapidot, M.D., the chief of pediatric infectious diseases at Rambam Health Care Campus in Israel, and an investigator in the Stride-13 trial, said in a release.
Lapidot added that children and adolescents may benefit from the additional coverage provided by Capvaxive, which defends against serotypes not included in other pneumococcal disease shots for infants.
Results were presented Thursday at the 6th European Society of Clinical Microbiology and Infectious Diseases (ESCMID) Conference on Vaccines in Lisbon, Portugal.
Merck said it will share the data with global regulatory authorities.
“While Capvaxive was designed to specifically cover the serotypes that cause the majority of invasive pneumococcal disease cases in adults, findings from Stride-13 underscore its added potential to help protect children and adolescents who are at an increased risk,” Paula Annunziato, who heads up Merck’s infectious diseases and vaccines development, added in a statement.
The value of Capvaxive for patients 50 and older is that its 21 serotypes account for 84% of the pneumococcal disease of people in the age group, compared to a 52% figure in the same population for the 20 serotypes covered by the world’s dominant pneumococcal shot, Pfizer’s Prevnar 20, which is allowed in children and adults.
Sales of Capvaxive have scaled up from $50 million in the fourth quarter of 2024 to $107 million in the first quarter of this year, followed by a $129 million showing in the second quarter.