Merck 21-valent Pneumococcal Conjugate Vaccine demonstrates superior immunogenicity for 10 of 11 Unique Serotypes compared to PCV20 in adults 50 years of age and older

Results from the study’s primary objectives include:

• In adults 50 years of age and older (Cohort 1), V116 elicited non-inferior immune responses compared to PCV20 for all 10 serotypes common to both vaccines as measured by serotype-specific opsonophagocytic activity (OPA) geometric mean titers (GMTs) at Day 30.
• Immune responses elicited by V116 were superior for 10 of 11 serotypes included in V116 but not in PCV20 as measured by OPA GMTs at Day 30 and the proportions of patients with a greater than or equal to four-fold increase in OPA from Day 1 to Day 30.
• In adults 18 to 49 years of age (Cohort 2), V116 elicited non-inferior immune responses (immunobridged) compared to adults 50 to 64 years of age, as assessed by serotype-specific OPA GMTs 30 days post-vaccination.
• Across both cohorts, V116 had a safety profile comparable to PCV20.

The company announced topline results of the STRIDE-3 trial earlier this year.

According to CDC data from 2018-2021, the serotypes covered by V116 are responsible for approximately 83% of invasive pneumococcal disease in individuals 65 years of age and older. V116 includes eight unique serotypes not covered by currently licensed pneumococcal vaccines, which were responsible for approximately 30% of invasive pneumococcal disease in individuals 65 years of age and older, based on the same CDC data. If approved, V116 would be the first pneumococcal conjugate vaccine specifically designed for adults.

“These results provide strong evidence to support the immunogenicity of V116 compared to the standard of care in the prevention of invasive pneumococcal disease and pneumococcal pneumonia in adults,” said Dr. Eliav Barr, senior vice president, head of global clinical development and chief medical officer, Merck Research Laboratories. “We are excited by the potential of V116 to impact public health through primary prevention through the use of a population-specific strategy that targets the serotypes responsible for the majority of invasive pneumococcal disease in adults.”

“Invasive forms of pneumococcal disease can cause serious and sometimes life-threatening complications, such as pneumococcal pneumonia, pneumococcal meningitis and bacteremia, especially for older or immunocompromised adults,” said Dr. Sady Alpizar, Clinical Research Trials of Florida, Inc., and a principal investigator of the study. “These encouraging results demonstrate that V116 has the potential to help prevent invasive pneumococcal disease among vulnerable populations.”

The V116 Phase 3 clinical development program is composed of eight trials (n=8,830) investigating the safety, tolerability and immunogenicity of V116 in various adult populations. These include adults with and without chronic medical conditions associated with an increased risk of pneumococcal disease, as well as individuals who previously received a pneumococcal vaccine. 

Merck is sharing data from STRIDE-3 with global regulatory authorities.