Infectious Disease

Investigational 21-Valent Pneumococcal Conjugate Vaccine Immunogenic, Safe

Merck’s investigational 21-valent pneumococcal conjugate vaccine, V116, elicited positive immune responses in vaccine-naïve and previously vaccinated individuals, according to results from two phase 3 trials.

The randomized, double-blind, active comparator-controlled STRIDE-3 (ClinicalTrials.gov Identifier: NCT05425732) and STRIDE-6 (ClinicalTrials.gov Identifier: NCT05420961) studies evaluated the safety and immunogenicity of V116 in pneumococcal vaccine-naïve adults 18 years of age and older (n=2600) and adults 50 years of age and older who previously received a pneumococcal vaccination at least 1 year prior to study enrollment (n=717), respectively. 

In STRIDE-3, patients were randomly assigned to receive 1 dose of either V116 or PCV20 (pneumococcal 20-valent conjugate vaccine). In STRIDE-6, patients were randomly assigned to receive 1 dose of either V116, PCV15 (pneumococcal 15-valent conjugate vaccine), or PPSV23 (pneumococcal vaccine, polyvalent [23-valent]). 

These results support the potential for V116 to become an important new preventive option for adults, regardless of prior pneumococcal vaccination status, by expanding coverage to include 8 serotypes not currently included in any licensed vaccine.

Among vaccine-naïve adults in STRIDE-3, V116 demonstrated statistically significant immune responses compared with PCV20 for serotypes common to both vaccines, as well as positive immune responses to serotypes unique to V116 (Streptococcus pneumoniae serotypes 15A, 15C, 16F, 23A, 23B, 24F, 31 and 35B), as assessed by serotype-specific opsonophagocytic activity 30 days postvaccination. Moreover, findings from STRIDE-6 showed that V116 was immunogenic for all 21 pneumococcal serotypes (S. pneumoniae serotypes 3, 6A/C, 7F, 8, 9N, 10A, 11A, 12F, 15A, 15B/C, 16F, 17F, 19A, 20, 22F, 23A, 23B, 24F, 31, 33F, 35B) in adults who previously received pneumococcal vaccination at least 1 year prior to the study. The safety profile of V116 was comparable to the comparators in both studies.

“Despite the availability of current pneumococcal conjugate vaccines, many adults remain vulnerable to pneumococcal disease, especially those who are older,” said Dr Eliav Barr, senior vice president, head of global clinical development and chief medical officer, Merck Research Laboratories. “These results support the potential for V116 to become an important new preventive option for adults, regardless of prior pneumococcal vaccination status, by expanding coverage to include 8 serotypes not currently included in any licensed vaccine.”

V116 was previously granted Breakthrough Therapy designation by the Food and Drug Administration for this indication.

This article originally appeared on MPR

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