Merck’s investigational pneumococcal vaccine V116 matched Pfizer’s Prevnar 20 vaccine in efficacy and safety, according to data from a Phase 3 trial released Tuesday morning.

The trial, STRIDE-3, found that V116 provided non-inferior immune responses to Prevnar 20, which was just approved by the Food and Drug Administration in April for use in children and infants.

In particular, V116 evoked an immune response that was superior for 10 out of 11 serotypes, which was measured by serotype-specific opsonophagocytic activity (OPA) geometric mean titers (GMTs).

Those serotypes that V116 targets reportedly cause about 83% of pneumococcal disease in older people, according to the Centers for Disease Control and Prevention (CDC). 

Pneumococcal disease is an umbrella term for illnesses caused by the Streptococcus pneumoniae bacteria, ranging from sinus infections and pneumonia to blood infections.

In elderly or immunocompromised patients, pneumococcal disease can lead to serious complications like meningitis, pneumonia and bacteremia.

This would make V116 the first pneumococcal vaccine that specifically targets adults, Merck said in a company 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,” stated Dr. Eliav Barr, SVP, head of global clinical development and chief medical officer at Merck Research Laboratories.

The data release marks V116’s rise as a potential competitor to Prevnar 20, which is currently in command of the pneumococcal vaccine market. 

However, other players like GSK have been aiming to take a bite of the market as well, with the British pharma giant acquiring Affinivax for $2.1 billion upfront in 2022. That deal gave GSK access to Affinavix’s 24-valent pneumococcal vaccine, AFX3772.

In addition, Vaxcyte reported positive data in April from a Phase 2 study of VAX-24, its own 24-valent pneumococcal vaccine.

The STRIDE-3 data also comes on the heels of an FDA rejection of Merck’s chronic cough drug, gefapixant. An FDA committee voted 12-1 against the drug, pointing to the marginal clinical benefit provided.

Still, Merck is banking on the strong results in STRIDE-3 and will seek approval for V116, though it did not state when that would be. Merck noted it would be sharing the STRIDE-3 data with global regulators.

Dr. Sady Alpizar, principal investigator of STRIDE-3, added that these results demonstrate that V116 has the potential to help prevent invasive pneumococcal disease among vulnerable populations.