The FDA has approved an expanded indication for a 21-valent pneumococcal conjugate vaccine for children and teens aged 2-17 years who are at increased risk for pneumococcal disease and who have completed a primary pediatric pneumococcal vaccine series, according to a press release from manufacturer Merck. 

The vaccine, marketed as CAPVAXIVE, is now indicated for the prevention of invasive pneumococcal disease for younger individuals at increased risk because of one or more chronic medical conditions, according to Merck. 

CAPVAXIVE targets invasive pneumococcal 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. The vaccine was previously approved for the prevention of invasive pneumococcal disease in individuals aged 18 years and older and 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 aged 18 years and older.

The new indication follows an accelerated approval process based on immune responses measured by opsonophagocytic activity, and continued approval may depend on verification and description of benefits in an confirmatory clinical trial, according to the company. 

The approval was supported by data from the STRIDE-13 phase 3 study, in which 874 children and teens ages 2- 17 years with one or more chronic medical conditions that placed them at increased risk for pneumococcal disease were randomized to the pneumococcal 23-valent polysaccharide vaccine, PPSV23 (n = 347) or CAPVAXIVE (n = 527). All participants had completed a primary pediatric pneumococcal vaccination series.

Overall, CAPVAXIVE was associated with significantly greater opsonophagocytic activity geometric mean titers for the nine serotypes distinctive to the vaccine, and noninferior to PPSV23 for the 12 serotypes shared by both vaccines. In addition, CAPVAXIVE was noninferior to PPSV23 for serotyped 15B in a post hoc analysis. 

Safety profiles were similar for the two vaccines, with most adverse events lasting 3 days or less. A total of 29 patients in the CAPVAXIVE group and 25 in the PPSV23 group reported one or more serious adverse events within 6 months of vaccination. The most common adverse events among individuals aged 2-17 years were injection site pain (67.7%), injection site erythema (24.3%), fatigue (20.1%), injection site swelling (18.8%), headache (17.1%), malaise (13.3%), and irritability (11.6%). 

The vaccine is given as a single 0.5 mL dose via intramuscular injection. Full prescribing information is available here. 

The research to support the approval was funded by Merck.