The vaccine covers serotypes responsible for approximately 84% of invasive pneumococcal disease in adults 50 years of age and older.

RT’s Three Key Takeaways:

  1. The FDA approved Merck’s Capvaxive, a 21-valent pneumococcal conjugate vaccine, designed to protect adults against serotypes causing the majority of invasive pneumococcal disease and pneumonia.
  2. Capvaxive includes eight unique serotypes not covered by other approved pneumococcal vaccines, covering approximately 84-85% of invasive pneumococcal disease cases in adults 50 years and older, compared to 52% covered by PCV20.
  3. The approval is based on robust immunogenicity demonstrated in phase 3 STRIDE-3, STRIDE-5, and STRIDE-6 trials, highlighting Capvaxive’s effectiveness in both vaccine-naïve and vaccine-experienced adults.

Merck announced today that the US Food and Drug Administration (FDA) has approved its Capvaxive pneumococcal 21-valent conjugate vaccine.

Capvaxive is specifically designed to help protect adults against the serotypes that cause the majority of invasive pneumococcal disease cases. The approval follows the FDA’s Priority Review of Merck’s application.

The vaccine is for:

  • Active immunization for the prevention of invasive disease caused by Streptococcus pneumoniae serotypes 3, 6A, 7F, 8, 9N, 10A, 11A, 12F, 15A, 15B, 15C, 16F, 17F, 19A, 20A, 22F, 23A, 23B, 24F, 31, 33F, and 35B in individuals 18 years of age and older;
  • Active immunization for the prevention of pneumonia caused by S. pneumoniae serotypes 3, 6A, 7F, 8, 9N, 10A, 11A, 12F, 15A, 15C, 16F, 17F, 19A, 20A, 22F, 23A, 23B, 24F, 31, 33F, and 35B in individuals 18 years of age and older.

The indication for the prevention of pneumonia caused by Streptococcus pneumoniae serotypes 3, 6A, 7F, 8, 9N, 10A, 11A, 12F, 15A, 15C, 16F, 17F, 19A, 20A, 22F, 23A, 23B, 24F, 31, 33F, and 35B is approved under accelerated approval based on immune responses as measured by opsonophagocytic activity. Continued approval for this indication may be contingent upon verification and description of clinical benefit in a confirmatory trial.

CDC Advisory Committee Recommendations

The US Centers for Disease Control and Prevention’s (CDC) Advisory Committee on Immunization Practices is expected to meet later this month to discuss and make recommendations for the use of Capvaxive in adults.

“Complications from invasive pneumococcal disease can lead to hospitalization, organ damage, and even death. Many cases of adult disease are caused by serotypes not included in other approved pneumococcal conjugate vaccines,” says Walter Orenstein, MD, professor emeritus of medicine, epidemiology, global health, and pediatrics at Emory University and member of Merck’s Scientific Advisory Committee, in a release. “Capvaxive is designed to include the serotypes that cause the majority of invasive pneumococcal disease in adults, helping to protect adults against invasive pneumococcal disease and pneumococcal pneumonia.”

Efficacy Compared to PCV20

Based on CDC data from 2018-2021, the serotypes covered by Capvaxive are responsible for more cases of invasive pneumococcal disease in adults compared to PCV20 (pneumococcal 20-valent conjugate vaccine).

  • In adults 50 years of age and older, Capvaxive covers the serotypes responsible for approximately 84% of IPD cases, compared to approximately 52% covered by PCV20.
  • In adults 65 years of age and older, Capvaxive covers the serotypes responsible for approximately 85% of IPD cases, compared to approximately 51% covered by PCV20.

These values are based on CDC epidemiologic data and do not reflect the efficacy of the respective vaccines. There are currently no studies comparing the efficacy of Capvaxive and PCV20.

Unique Serotype Coverage and Clinical Data

Capvaxive includes eight unique serotypes not covered by other currently approved pneumococcal vaccines; those serotypes were responsible for approximately 27% of invasive pneumococcal disease cases in adults 50 years of age and older and approximately 30% in adults 65 years of age and older, based on the same CDC data.

“Today’s approval is a testament to our population-specific strategy behind Capvaxive, which demonstrated robust immunogenicity in a range of adult populations and is driven by a deep understanding of pneumococcal disease,” says Dean Y. Li, MD, PhD, president of Merck research laboratories, in a release. “We are proud to provide Capvaxive as a new option specifically designed to help protect against the majority of invasive pneumococcal disease-causing serotypes in adults.”

Among the clinical data supporting the approval are results from the phase 3 STRIDE-3 trial, which evaluated Capvaxive compared to PCV20 in adults 18 years of age and older who had not previously received a pneumococcal vaccine. The approval is also supported by results from the phase 3 STRIDE-5 and STRIDE-6 trials evaluating Capvaxive in vaccine-naïve and vaccine-experienced adults.

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