Merck’s Capvaxive, the world’s first pneumococcal disease vaccine tailored for adults, has cleared a crucial hurdle in its challenge against Pfizer’s Prevnar franchise. Following its recent approval, the vaccine received unanimous backing from the CDC’s Advisory Committee on Immunization Practices (ACIP) this week, with one abstention.
ACIP’s endorsement extends Capvaxive to adults aged 65 and older who haven’t received a pneumococcal conjugate vaccine, as well as to adults aged 19 to 64 with certain underlying medical conditions or risk factors. Additionally, adults who began their vaccine series with Pfizer’s Prevnar 13 but haven’t completed all recommended doses of Merck’s Pneumovax 23 are also included.
Merck’s Chief Medical Officer, Dr. Eliav Barr, expressed optimism following the ACIP vote, highlighting Capvaxive’s clinical profile and anticipating final recommendations from the CDC.
Capvaxive guards against 21 serotypes of pneumococcal bacteria, covering 84% of infections in adults aged 50 and older, as per CDC data. In comparison, Pfizer’s Prevnar 20 protects against 20 serotypes, covering 52% of the same population’s infections.
Analysts at Leerink noted that Merck’s differentiated disease coverage could appeal strongly to buyers and prescribers, yet they emphasized that Merck faces a significant challenge in surpassing Pfizer’s dominant position. ACIP’s decision to defer a vote on recommending Capvaxive for adults aged 50 to 64 suggests ongoing deliberations over broader age recommendations, expected to be finalized in October.
Looking ahead, Vaxcyte is developing a potentially game-changing 24-valent vaccine, aiming for broader serotype coverage. The company plans to present phase 1/2 study results to ACIP before the October meeting.
Merck’s Capvaxive adds to its portfolio alongside Vaxneuvance, a 15-valent pneumococcal vaccine that generated $665 million in sales last year. In contrast, Pfizer’s Prevnar franchise reported revenue of $6.4 billion in 2023, underscoring the competitive landscape in pneumococcal disease prevention.