Merck Wins FDA Approval for First Pneumococcal Vaccine Designed for Adults

Pictured: Merck's head office in Quebec, Canada

Pictured: Merck’s head office in Quebec, Canada

iStock, JHVEPhoto

Merck on Monday secured the FDA’s green light for its 21-valent pneumococcal vaccine Capvaxive, which covers serotypes responsible for around 84% of invasive pneumococcal disease cases.

The FDA on Monday greenlit Merck’s 21-valent pneumococcal conjugate vaccine to prevent invasive pneumococcal disease and pneumococcal pneumonia in adults. The vaccine will be sold under the brand name Capvaxive.

Merck’s vaccine is designed to cover pneumococcal strains responsible for approximately 84% of invasive pneumococcal disease (IPD), according to the announcement. Capvaxive also includes eight unique serotypes that are not targeted by currently commercialized pneumococcal vaccines. Together, these eight strains account for around 27% of IPD cases in adults aged 50 and older, and for some 30% of cases in seniors 65 years and older.

Capvaxive’s pneumococcal pneumonia indication was approved under the FDA’s accelerated pathway and its continued approval will depend on the validation of clinical benefit in a confirmatory study.

“Capvaxive is designed to include the serotypes that cause the majority of invasive pneumococcal disease in adults,” Walter Orenstein, professor emeritus of medicine, epidemiology, global health and pediatrics at Emory University, said in a statement. “Many cases of adult disease are caused by serotypes not included in other approved pneumococcal conjugate vaccines.”

Orenstein serves as a member of Merck’s scientific advisory committee.

Capvaxive’s approval is based partly on the Phase III STRIDE-3 study, which found that Merck’s shot was non-inferior to a commercially available 20-valent comparator vaccine. According to a November 2023 readout, Capvaxive was also able to elicit superior immune responses for 10 of the 11 serotypes that were not covered by its 20-valent comparator.

Safety data from STRIDE-3 showed that Capvaxive had a similar adverse event and tolerability profile as the comparator vaccine.

Data from the Phase III STRIDE-4 and STRIDE-6 studies, which assessed Capvaxive in vaccine-naïve and vaccine-experienced adults, also backed Monday’s regulatory win.

With Capvaxive’s approval, Merck is poised to compete with Pfizer whose 20-valent shot Prevnar 20 currently dominates the market. The vaccine was first approved in June 2021 for the immunization of adults aged 18 years and older against IPD and pneumonia. The FDA expanded the vaccine’s label in April 2023, allowing its use in infants and children six weeks through 17 years of age.

For Pfizer, the Prevnar family of vaccines—which also includes Prevnar 13—has been a major source of revenue. In the first quarter of 2024, Prevnar products generated 7% year-over-year growth operationally, driven primarily by its pediatric indication. In Q1, Prevnar vaccines brought in a total of $1.7 billion worldwide.

Tristan Manalac is an independent science writer based in Metro Manila, Philippines. Reach out to him on LinkedIn or email him at tristan@tristanmanalac.com or tristan.manalac@biospace.com.

Tristan is an independent science writer based in Metro Manila, with more than eight years of experience writing about medicine, biotech and science. He can be reached at tristan.manalac@biospace.com, tristan@tristanmanalac.com or on LinkedIn.
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