FDA Approves CAPVAXIVE™ Vaccine for Adult Pneumococcal Disease Prevention

Merck & Co. has announced that the U.S. Food and Drug Administration (FDA) has approved CAPVAXIVE™ (Pneumococcal 21-valent Conjugate Vaccine) for use in adults aged 18 and older. This vaccine is designed to prevent invasive disease and pneumonia caused by specific serotypes of Streptococcus pneumoniae. These serotypes include 3, 6A, 7F, 8, 9N, 10A, 11A, 12F, 15A, 15B, 15C, 16F, 17F, 19A, 20A, 22F, 23A, 23B, 24F, 31, 33F, and 35B.

CAPVAXIVE targets the serotypes responsible for a significant proportion of invasive pneumococcal disease (IPD) cases in adults, especially those 50 years and older. The FDA approval followed a Priority Review, underscoring the importance of this vaccine in addressing public health needs. CAPVAXIVE's coverage extends to serotypes responsible for about 84% of IPD cases in adults aged 50 and older, compared to around 52% covered by PCV20, another pneumococcal conjugate vaccine. For adults aged 65 and older, these figures are 85% and 51%, respectively.

The approval is supported by data from multiple Phase 3 studies, including the STRIDE-3, STRIDE-5, and STRIDE-6 trials. These studies evaluated the safety and immunogenicity of CAPVAXIVE in both vaccine-naïve and vaccine-experienced adults. For instance, the STRIDE-3 trial compared CAPVAXIVE to PCV20 in adults 18 and older who had not previously received a pneumococcal vaccine. The results indicated that CAPVAXIVE was non-inferior to PCV20 for the shared serotypes and superior for the unique serotypes included in CAPVAXIVE but not in PCV20.

The vaccine was also evaluated in the STRIDE-5 trial, which looked at its co-administration with a quadrivalent influenza vaccine (QIV) in adults 50 years and older. The findings showed that CAPVAXIVE could be administered with QIV without compromising the immune response to either vaccine. Additionally, the STRIDE-6 trial assessed CAPVAXIVE in vaccine-experienced adults, finding it comparable to PCV15 and PPSV23 for common serotypes and superior for its unique serotypes.

CAPVAXIVE includes eight serotypes not covered by other approved pneumococcal vaccines, providing broader protection. These additional serotypes account for about 27% of IPD cases in adults aged 50 and older and approximately 30% in adults aged 65 and older, based on CDC data from 2018-2021.

Dr. Walter Orenstein, a member of Merck’s Scientific Advisory Committee, emphasized that complications from invasive pneumococcal disease can lead to severe outcomes, including hospitalization and death. He noted that many adult cases are caused by serotypes not included in other pneumococcal vaccines, highlighting the importance of CAPVAXIVE in offering broader protection.

Dr. Dean Y. Li, president of Merck Research Laboratories, praised the approval as a testament to Merck's strategy in developing a vaccine specifically designed to address the serotypes causing most adult IPD cases. He noted that CAPVAXIVE demonstrated robust immunogenicity across various adult populations.

In terms of safety, CAPVAXIVE should not be administered to individuals with a history of severe allergic reactions to any component of the vaccine or to diphtheria toxoid. Common adverse reactions include injection-site pain, fatigue, and headache, with varying prevalence depending on the age group.

CAPVAXIVE is administered as a single dose and is now a new option to help protect adults against invasive pneumococcal disease and pneumonia, complementing the existing vaccines and potentially reducing the disease burden significantly.