FDA concerned over GSK asthma drug risk

The FDA has reported that UK-headquartered pharmaceutical company GlaxoSmithKline's (GSK) asthma drugs Serevent (salmeterol) and Advair (fluticasone) may cause rare and deadly side effects in children.

Swiss-based Novartis' Foradil (formoterol) for asthma is also under scrutiny.

The FDA says that nine patients under age 16 were harmed, including five who died, while being administered Serevent in the last 13 months, according to a safety review posted on the agency's website on 23 November. 

A meeting to discuss side effects from the medications is scheduled for 27 November.

In 2005, the FDA advised consumers to limit the use of the drugs to patients who did not benefit from other similar medication, following a study that showed chances of asthma-related deaths among Serevent users increased 400 per cent. The agency put a ìblack boxî warning on the drug labelling in 2006.

The new FDA report said that there was no available paediatric data exclude the increased risk of asthma death and life-threatening exacerbations observed in adults. However the agency went on to say that Serevent benefits outweighed the more risks.

Advair and Serevent racked up FY06 global sales of USD 6.1bn and increased GSK's sales by 12 per cent, which made the treatments the second-best-selling in the world after Pfizer's cholesterol-lowing drug Lipitor (atorvastatin).

Other asthma drugs in development include SkyePharma Flutiform (fluticasone/ formoterol), the phase III studies of which were successfully completed at the beginning of November 2007.

With annual sales expected to be in the region of USD 1bn, Flutiform, if approved, would compete with Advair/Seretide and AstraZeneca's Symbicort (budesonide/ formoterol).

Flutiform's progression towards US approval was halted after an August 2007 FDA announcement that the New Drug Application (NDA) would be delayed. Originally planned for submission in Q1 2008, the Flutiform NDA will now not be submitted until H2 2008, following the request from the FDA for another clinical study to provide additional efficacy data.

The US market for asthma drugs exceeded USD 10bn in 2005, and the fastest growing segment of this market is fixed combination treatments, according to in-pharmatechnologist.com.