Biopharmaceutical company Merck (NYSE: MRK), also known as MSD outside the US and Canada, has announced positive results from the STRIDE-8 Phase 3 trial for CAPVAXIVE (Pneumococcal 21-valent Conjugate Vaccine), presented at IDWeek 2024 in Los Angeles. This study evaluated the immunogenicity, safety and tolerability of CAPVAXIVE in vaccine-naïve adults aged 18-64 with chronic conditions that increase their risk of pneumococcal disease.

CAPVAXIVE demonstrated robust immune responses for all 21 serotypes included in the vaccine. Key findings showed that immune responses were comparable to those elicited by the PCV15 followed by PPSV23 regimen for the 13 common serotypes, while responses were significantly higher for the eight unique serotypes in CAPVAXIVE. Additionally, adverse events were numerically lower in participants receiving CAPVAXIVE compared to those receiving the combination of PCV15 and PPSV23.

CAPVAXIVE is indicated for active immunization against invasive disease and pneumonia caused by various Streptococcus pneumoniae serotypes in adults 18 years and older. It is specifically designed to address serotypes responsible for approximately 84% of invasive pneumococcal disease (IPD) cases in adults aged 50 and older, compared to about 52% covered by the pneumococcal 20-valent conjugate vaccine (PCV20).

Alongside STRIDE-8 results, Merck presented findings from a literature review highlighting disparities in pneumococcal disease burden among Black adults and those in rural areas with lower income and education levels. Additionally, a modeling study suggested that CAPVAXIVE could reduce IPD incidence by 33.9% in the U.S. over ten years, leading to approximately 14,000 fewer cases compared to PCV20.

Merck remains committed to advancing pneumococcal disease prevention through ongoing vaccine development, aiming to address the needs of diverse populations.