Merck (NYSE: MRK), known as MSD outside the United States and Canada, today announced findings from two additional Phase 3 studies evaluating the safety, tolerability and immunogenicity of V114, the company’s investigational 15-valent pneumococcal conjugate vaccine. In the PNEU-PATH (V114-016) study, healthy adults 50 years of age or older received V114 or PCV13 followed by PNEUMOVAX 23 one year later. Immune responses following vaccination with PNEUMOVAX 23 (month 13) were comparable in both vaccination groups for the 15 serotypes in V114. Results also showed that at 30 days post vaccination with either V114 or PCV13 (day 30), immune responses were comparable for both groups across the 13 serotypes shared by the conjugate vaccines and higher in the V114 group for serotypes 22F and 33F, the two serotypes not included in PCV13. In PNEU-DAY (V114-017), a Phase 3 study in immunocompetent adults 18 to 49 years of age with underlying medical conditions associated with increased risk for pneumococcal disease, V114 generated immune responses generally comparable to PCV13 for the 13 shared serotypes and higher immune responses for serotypes 22F and 33F at 30 days post-vaccination. Results from both studies are based on opsonophagocytic activity (OPA) responses – a measure of vaccine-induced functional antibodies. V114 was generally well tolerated in both studies, with a safety profile consistent with that observed for V114 in previously reported studies.

“Pneumococcal disease in adults is on the rise globally, in part driven by disease-causing serotypes not targeted by the currently available pneumococcal conjugate vaccine,” said Dr. Roy Baynes, senior vice president and head of global clinical development, chief medical officer, Merck Research Laboratories. “These data provide important information about the potential for V114 followed by PNEUMOVAX 23, a polysaccharide vaccine included in more than 90 percent of age-based adult pneumococcal immunization programs globally, to help protect healthy adults and adults who are at increased risk for pneumococcal disease.”

Findings from the V114 Phase 3 clinical program in adults, including PNEU-PATH and PNEU-DAY, will be presented at a future scientific congress. Plans for global regulatory licensure applications, beginning with the U.S. Food and Drug Administration before the end of the year, remain on track.