BETHESDA, MD. — A Food and Drug Administration advisory panel voted in favor of recommending Pfizer's 13-valent pneumococcal conjugate vaccine for the prevention of invasive pneumococcal disease.
The FDA's Vaccines and Related Biological Products Advisory Committee (VRPAC) said that the data support the efficacy and safety of Prevnar 13, based on two phase III trials involving a total of 2,362 subjects randomized to either PCV13 or the current 7-valent Prevnar (PCV7) at 2, 4, 6, and 12–15 months of age.
“The VRPAC decision is an important step toward licensing of PCV13,” Dr. Joseph A. Bocchini Jr., chair of the American Academy of Pediatrics Committee on Infectious Diseases (COID), said in an interview.
The COID has been reviewing the data from the clinical trials of PCV13 as they have become available and is working closely with the Centers for Disease Control and Prevention's Advisory Committee on Immunization Practices on draft recommendations, said Dr. Bocchini, professor and chairman of the department of pediatrics at Louisiana State University Health Sciences Center, Shreveport. “PCV13 has the potential to further reduce the burden of invasive pneumococcal disease in infants and children. Based on available data COID believes that, if licensed, there would be a smooth transition from PCV7. The dosing schedule used in the trials is the same as [for] PCV7,” he commented.
While the VRPAC's vote was nearly unanimous (10–1) in support of the vaccine for the prevention of invasive pneumococcal disease (IPD), some members questioned whether the data support an indication for PCV13 for the prevention of otitis media, which was included in the company's licensing application. The panel didn't vote on that issue, but several members requested further otitis media data for the six additional strains contained in PCV13 that were not in the current 7-valent Prevnar, which does have an indication for prevention of otitis media.
The 13-valent formulation is composed of capsular polysaccharides derived from the seven pneumococcal serotypes contained in the current 7-valent Prevnar (4, 6B, 9V, 14, 18C, 19F, and 23F), and from six additional serotypes (1, 3, 5, 6A, 7F, and 19A). It is manufactured in the same way as Prevnar, by individual conjugation of each capsular polysaccharide to diphtheria protein, said Dr. Emilio A. Emini, Pfizer Inc.'s chief scientific officer for vaccine research.
According to Dr. Matthew R. Moore, an epidemiologist at the Centers for Disease Control and Prevention, at the time PCV7 was licensed in 2000, its seven strains accounted for 80% of IPD in young children in North America. Since then, though the rates of IPD from PCV7 strains declined by 99%, overall IPD rates began to level off in 2002, because of an increase in the incidence of IPD caused by non-PCV7 strains, particularly 19A.
The six additional pneumococcal strains contained in PCV13 were responsible for approximately 62% of IPD cases in children younger than 5 years in 2007. In the same age group, the 13 serotypes contained in PCV13 were responsible for approximately 64% of IPD cases in 2007, he said.
Both Pfizer and the FDA announced plans to conduct phase IV postmarketing studies of efficacy and safety.
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