21-valent Pneumococcal Conjugate Vaccine Candidate Designed for Adults Met Phase 3 Clinical Trials Endpoints

Merck today announced positive topline results from two Phase 3 trials evaluating V116, the company's investigational 21-valent pneumococcal conjugate vaccine in vaccine-naïve and previously vaccinated individuals.

In both studies, V116 had a safety profile comparable to the comparator in the studies.

Results from the STRIDE-3 clinical trial demonstrated statistically significant immune responses compared to PCV20 (pneumococcal 20-valent conjugate vaccine) in vaccine-naïve adults for serotypes common to both vaccines as assessed by serotype-specific opsonophagocytic activity (OPA) 30 days post-vaccination.

Positive immune responses were also observed for serotypes unique to V116.

Additionally, results from STRIDE-6 demonstrated that V116 was immunogenic for all 21 pneumococcal serotypes in the vaccine among adults who previously received a pneumococcal vaccine at least one year before the study.

If approved, V116 would be the first pneumococcal conjugate vaccine designed for adults, says Merck.

Dr. Eliav Barr, senior vice president, head of global clinical development, and chief medical officer of Merck Research Laboratories, said in a press release on July 27, 2023, "These results support the potential for V116 to become an important new preventative option for adults, regardless of prior pneumococcal vaccination status, by expanding coverage to include eight serotypes not currently included in any licensed vaccine."

According to pre-pandemic 2019 U.S. CDC data, the 21 serotypes covered by V116 are responsible for 85% of invasive pneumococcal disease in individuals 65 and older.

V116 includes eight serotypes not currently covered by approved pneumococcal vaccines.

Serotypes unique to V116 include 15A, 15C, 16F, 23A, 23B, 24F, 31, and 35B, which were responsible for approximately 30% of invasive pneumococcal disease in individuals 65 and older, based on pre-pandemic 2019 U.S. CDC data.