Glaxo confident as FDA probes asthma drugs in kids

LONDON (Reuters) - The safety of GlaxoSmithKline Plc's top-selling asthma drugs Serevent and Advair is back in the spotlight this week as a U.S. regulatory panel meets to consider their safety in children.

Europe's biggest drugmaker said on Monday it remained confident the benefits of its products outweighed any risks.

Concerns about rare and potentially fatal side effects were raised in briefing documents posted by Food and Drug Administration staff ahead of a November 27-29 meeting of the agency's Pediatric Advisory Committee.

There were nine cases of adverse events in children under 16 using Serevent, or salmeterol, in the year following granting of pediatric market exclusivity in March 2006, including five deaths, papers posted on the FDA Web site show (here%20Adverse%20Event%20Review.pdf).

Serevent, a long-acting beta agonist used to ease breathing, is also included in Advair, Glaxo's biggest product with worldwide sales of 3.3 billion pounds ($6.8 billion) in 2006. U.S. sales accounted for 1.9 billion pounds last year.

The British-based company said it had provided clinical information to the FDA, which it believed backed the safety of both products.

"GSK has submitted a thorough safety review of salmeterol-containing products in pediatrics. The overall assessment of the data confirms the favorable safety and efficacy profile of Serevent and Advair when used according to the product labels," a spokeswoman said.

"GSK believes the product labels reflect the available safety information for children four years of age and older."

It is not the first time that rare adverse events have been reported with Advair and Serevent and industry analysts said the latest regulatory scrutiny would probably not have any immediate impact.