- The Food and Drug Administration has approved Merck & Co.'s next-generation pneumococcal vaccine Vaxneuvance, which covers 15 strains of the bacteria that can cause invasive infections. The decision comes about a month after the agency cleared Pfizer's new shot, Prevnar 20, which protects against 20 strains.
- The approval was based in part on data showing that Merck's vaccine spurred greater immune responses against three key bacterial strains than Pfizer's old shot, Prevnar 13, one of the world's best-selling pharmaceutical products. Vaxneuvance has not been compared to Prevnar 20 in testing.
- The decision extends a long-running battle between the two of the world's top vaccine makers. Pfizer has been largely winning, with Prevnar 13 outselling Merck's Pneumovax 23 by nearly five to one. Merck aims to compete with Vaxneuvance, which is meant to protect people from bacteria associated with higher levels of hospitalizations and antibiotic resistance.
Despite all of the focus on Pfizer and partner BioNTech's coronavirus vaccine, Prevnar 13 was the pharma's biggest-selling drug of 2020, earning $5.9 billion in revenue. The massive figure underscores the size of the market and the importance of the pneumococcal vaccine business to the company. In a July 18 note to clients, Louise Chen, an analyst with Cantor Fitzgerald, estimated the global market is worth $7 billion and growing.
Pfizer's shot has been so effective in driving down rates of pneumococcal disease — which can include lung, ear, sinus and blood infections — that the Centers for Disease Control and Prevention no longer recommends it for all people over age 65. The CDC now recommends Merck's Pneumovax 23, launched in 1983, for most elderly people.
Before Prevnar 13 and others were introduced, two strains, known as serotypes 14 and 19A, dominated invasive pneumococcal disease. The situation has changed as emerging strains present new challenges for drugmakers.
Merck tested Vaxneuvance's efficacy against all 13 serotypes that Prevnar 13 protects people from. The drugmaker found its shot was "non-inferior," meaning it stimulated a similar antibody response. In addition, Merck's researchers measured a statistically superior antibody response for a strain that both of them protect against, serotype 3, and for two serotypes unique to Vaxneuvance, 22F and 33F.
Those three serotypes have been identified as major drivers of invasive disease. Prevnar 20 protects against all three of them as well, and Vaxneuvance hasn't been directly compared in an efficacy trial against either Pfizer shot.
The new approvals could have big implications for the CDC's Advisory Committee on Immunization Practices, which is scheduled to discuss updates to its pneumococcal vaccine recommendations in October. Among the proposals is lowering the age of pneumococcal vaccine in adults to 50, as well as switching younger patients with chronic medical conditions from Pneumovax 23 to Prevnar 20.