Investigational Vaccine Has Non-Inferior Immune Response Compared to PCV20 for Pneumococcal Disease

Author(s):

Ashley Gallagher, Associate Editor

Clinical trial results show the immunogenicity, tolerability, and safety of V116 compared to a pneumococcal 20-valent conjugate vaccine for adults who had not previously received a pneumococcal vaccine.

In adults aged 50 years or older, V116 (Merck), an investigational 21-valent pneumococcal conjugate vaccine, had a non-inferior immune response compared to the pneumococcal 20-valent conjugate vaccine (PCV20; Merck) for all 10 common serotypes, according to results of the STRIDE-3 trial.

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The phase 3 clinical trial evaluated the immunogenicity, tolerability, and safety of V116 compared to PCV20 for adults who had not previously received a pneumococcal vaccine, according to the press release.

“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,” Eliav Barr, MD, senior vice president, head of global clinical development, and chief medical officer at Merck Research Laboratories, said in a press release. “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.”

STRIDE-3 is a randomized, double-blind, active comparator-controlled study that was designed to evaluate the safety, tolerability, and immunogenicity of V116 compared to PCV20 for adults aged 18 and older who had not previously received a vaccine for pneumococcal disease. The individuals received a single dose of either vaccine. The primary endpoints included safety, serotype-specific opsonophagocytic activity geometric (OPG) mean titers at 30 days after vaccination, and percentage of individuals greater than or equal to a 4-fold increase from baseline for serotype-specific OPG. The trial had 2 cohorts, including one that included individuals aged 50 years and older and another that included individuals aged 19 to 49.

About The STRIDE-3 Trial

Trial Name: Safety and Immunogenicity of V116 in Pneumococcal Vaccine-naïve Adults (V116-003)

ClinicalTrial.gov ID: NCT05425732

Sponsor: Merck Sharp & Dohme LLC

Completion Date: May 2023

Investigators found that the immune responses elicited by V116 were superior for 10 of 11 serotypes that were included not included in PCV20, measured by OPA GMTs at 30 days and the proportion of individuals with a greater than or equal to a 4-fold increase in OPA from day 1 to day 30, according to the press release. For the aged 18 to 49 cohort, V116 elicited non-inferior immune responses compared to those aged 50 to 64.

In both cohorts, the safety profile of the 2 vaccines was comparable. Individuals who received either vaccine reported at least 1 adverse event (AE), including 61.7% of those who received V116 and 67.2% who received PCV20, according to the press release. There were no serious vaccine-related AEs or vaccine-related deaths in the study, according to the results.

“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,” Sady Alpizar, MD, from Clinical Research Trials of Florida Inc, said in the press release. “These encouraging results demonstrate that V116 has the potential to help prevent invasive pneumococcal disease among vulnerable populations.”

Detailed results of the STRIDE-3 were presented at World Vaccine Congress West Coast. The results will also be shared with regulatory authorities.

The study was part of a phase 3 clinical development trial evaluating V116, including 8 trials and various adult populations, according to the press release. It will include adults with and without chronic medical conditions associated with an increased risk of pneumococcal disease.

Reference

Merck’s V116, an investigational, 21-valent pneumococcal conjugate vaccine specifically designed to protect adults, demonstrated superior immunogenicity for 10 of 11 unique serotypes compared to PCV20 in adults 50 years of age and older. News release. Merck. November 28, 2023. Accessed November 29, 2023. https://www.businesswire.com/news/home/20231128147291/en