FDA approves Merck’s newest pneumococcal vaccine

Merck’s newly approved pneumococcal vaccine is expected to compete with Pfizer’s existing vaccines, pending CDC recommendations later this month. On June 17, 2024, the United States FDA approved CAPVAXIVE, a pneumococcal 21-valent conjugate vaccine that actively prevents invasive disease caused by Streptococcus pneumoniae serotypes 3, 6A, 7F, 8, 9N, 10A, 11A, 12F, 15A, 15B, 15C, 16F, 17F, 19A, 20A, 22F, 23A, 23B, 24F, 31, 33F and 35B, as well as pneumonia caused by serotypes 3, 6A, 7F, 8, 9N, 10A, 11A, 12F, 15A, 15C, 16F, 17F, 19A, 20A, 22F, 23A, 23B, 24F, 31, 33F and 35B in individuals 18 years of age and older.

“Complications from invasive pneumococcal disease can lead to hospitalization, organ damage, and even death. Many cases of adult disease are caused by serotypes not included in other approved pneumococcal conjugate vaccines,” said Walter Orenstein, MD, professor emeritus of medicine, epidemiology, global health and pediatrics at Emory University and member of Merck’s Scientific Advisory Committee, in the press release. “CAPVAXIVE is designed to include the serotypes that cause the majority of invasive pneumococcal disease in adults, helping to protect adults against invasive pneumococcal disease and pneumococcal pneumonia.”

According to Merck’s press release, Phase 3 STRIDE-3 clinical trial data comparing CAPVAXIVE to Pfizer’s pneumococcal 20-valent conjugate vaccine (PCV20) supported the drug’s approval. In the double-blind study, participants 18 and older were randomly assigned to receive one of the two vaccines. For participants between 18 and 49, the CAPVAXIVE vaccine was non-inferior to PCV20. Furthermore, in adults 50 and older, CAPVAXIVE was superior to PCV20.

In addition, the Merck press release emphasizes that the serotypes covered by CAPVAXIVE are more pertinent for invasive pneumococcal disease cases. For example, among adults 50 and older, CAPVAXIVE covers 84% of serotypes that cause invasive pneumococcal disease, while PCV-20 only covers 52% based on CDC epidemiologic data. Furthermore, in adults 65 and older, CAPVAXIVE covers 85% of serotypes that cause invasive pneumococcal disease, while PCV-20 only covers 51%.

“Today’s approval is a testament to our population-specific strategy behind CAPVAXIVE, which demonstrated robust immunogenicity in a range of adult populations and is driven by a deep understanding of pneumococcal disease,” said Dean Y. Li, MD, PhD, president of Merck Research Laboratories. “We are proud to provide CAPVAXIVE as a new option specifically designed to help protect against the majority of invasive pneumococcal disease-causing serotypes in adults.”

Editor's Note: This article has been corrected for serotype accuracy.