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Landmark Study Provides Positive Data for Prevnar 13 in Older Adults
Positive results have been reported from the Community-Acquired Pneumonia Immunization Trial in Adults (CAPiTA), a landmark study of approximately 85,000 subjects, demonstrating that Prevnar 13 (pneumococcal polysaccharide conjugate vaccine [13-valent, adsorbed], Pfizer) prevented a first episode of vaccine-type community-acquired pneumonia (VT-CAP) in adults 65 years of age and older — the study’s primary objective.
This trial is the first in adults to clearly demonstrate a significant reduction in pneumococcal VT-CAP and, importantly, in non-bacteremic/non-invasive VT-CAP. The results were presented March 12 at the 9th International Symposium on Pneumococci and Pneumococcal Diseases in Hyderabad, India.
The CAPiTA study also met both of its secondary study objectives: a significant reduction in 1) non-bacteremic/non-invasive VT-CAP and 2) vaccine-type invasive pneumococcal disease (VT-IPD).
Regarding the study’s primary objective, there were 46% fewer first episodes of VT-CAP among Prevnar 13-vaccinated subjects than among subjects who received placebo (P = 0.0006). Regarding the study’s secondary objectives, the Prevnar 13 group experienced 45% fewer first episodes of non-bacteremic/non-invasive VT-CAP (P = 0.0067) and 75% fewer first episodes of VT-IPD (P = 0.0005) compared with the placebo group.
Additional data showed reductions in VT-CAP, in non-bacteremic/non-invasive VT-CAP, and in VT-IPD for up to 4 years after vaccination among subjects who received the vaccine.
In 2011, Prevnar 13 was licensed by the FDA under an accelerated approval process to address an unmet medical need in older adults. As a requirement of the accelerated approval pathway, the CAPiTA trial was conducted to verify the vaccine’s clinical benefit.
The CAPiTA study was a parallel-group, randomized, placebo-controlled, double-blind trial in which subjects aged 65 years and older were randomly assigned to receive a single dose of either Prevnar 13 or placebo. A total of 84,496 subjects were enrolled. Fifty-eight sentinel hospitals were used for the surveillance of CAP and IPD.
VT-CAP was defined as CAP caused by any Streptococcus pneumoniae serotype included in the vaccine. Non-bacteremic/noninvasive VT-CAP was defined as CAP in which vaccine-type S. pneumoniae caused the pneumonia, but was not detected concurrently in the bloodstream or at any other normally sterile site. VT-IPD was defined as a case in which vaccine-type S. pneumoniae was present in the bloodstream or at any other normally sterile site, with or without pneumonia.
Pneumococcal disease refers to a group of illnesses caused by S. pneumoniae bacteria. Invasive pneumococcal disease occurs when bacteria enter the bloodstream or another site that is normally sterile. Non-invasive pneumococcal pneumonia occurs when the bacteria cause infection in the lungs but are not detected in the blood concurrently. In adults, pneumonia is the most common presentation of pneumococcal disease. For every case of invasive pneumococcal pneumonia in adults, it is estimated that at least three cases of non-invasive pneumococcal pneumonia occur. While non-invasive forms of pneumococcal disease are typically more common, the invasive types of disease are generally more severe.
In the U.S., Prevnar 13 is approved for use in adults 50 years of age and older for the prevention of pneumococcal pneumonia and invasive disease caused by 13 S. pneumoniae strains (1, 3, 4, 5, 6A, 6B, 7F, 9V, 14, 18C, 19A, 19F, and 23F). This indication is based on immune responses to the vaccine. Prevnar 13 is also indicated for the prevention of invasive disease caused by the 13 vaccine strains in children 6 weeks through 17 years of age, and for the prevention of otitis media caused by 7 of the 13 strains in children 6 weeks through 5 years of age.
Prevnar is not 100% effective and will only help protect against the 13 strains included in the vaccine. Its effectiveness when administered less than 5 years after a pneumococcal polysaccharide vaccine is not known.