US FDA advisory panel backs Pfizer's Prevnar 13

The US Food and Drug Administration's Vaccines and Related Biological Products advisory committee voted in favor (10 to one) of data presented to support the safety and effectiveness of global drug giant Pfizer's Prevnar 13, its 13-valent pneumococcal conjugate candidate vaccine acquired along with its $68 billion buy of fellow US drug major Wyeth. The favorable recommendation of the vaccine was based on data from 13 phase III studies carried out on more than 7,000 children.

Pfizer is seeking FDA approval for the vaccine to prevent diseases (including sepsis, meningitis, bacteremia, bacteremic pneumonia, and empyema caused by 13 Streptococcus pneumoniae (S. pneumoniae) in infants and young children. Although the FDA is not required to follow the advisory panel's recommendation, it generally does so. The agency is reviewing the Biologic License Application (BLA) for Prevnar 13, which has an action date of December 30, 2009. Though the FDA was initially expected to respond by September 30, it had pushed back the approval date then by 90 days.

The committee reviewed data from 13 Phase III studies involving more than 7,000 children and agreed that Prevnar 13's safety profile was 'adequate to support its safety,' Pfizer noted in a press statement.

Prevnar 13 is a new version of the currently available pneumococcal vaccine, Prevnar. Prevnar, one of the best selling vaccines worldwide, recorded sales of about $2.7 billion in 2008, comment analysts at Zacks Equity Research. While Prevnar treats illness caused by seven strains of pneumococcal bacteria, the new vaccine is expected to block 13 strains including the original seven, they noted. It is estimated that Prevnar 13 would cover 92% of invasive pneumococcal disease, compared to 81% covered by Prevnar. The company is currently seeking approval for Prevnar 13 in about 60 countries spanning six continents.

Earlier, in September, Prevnar 13 received a positive opinion from the European Medicines Agency's (EMEA) Committee for Medicinal Products for Human Use (CHMP). A final decision is expected by the European regulatory authorities by year end. In addition, the vaccine is being studied in global Phase III trials for the prevention of pneumococcal disease in adults.

Meanwhile, UK drug giant GlaxoSmithKline received European approval for its pediatric 10-valent vaccine, Synflorix (meant for children aged six weeks to two years) in March, which will compete with Prevnar and Prevnar 13. However, GSK does not have plans to launch the vaccine in the USA, the analysts said.