The UK drug giant submitted a Supplemental Drug Application to the US Food and Drug Administration (FDA) in October last year in a bid to market an increased 500/50 strength of Advair Diskus (fluticasone propionate and salmeterol inhalation powder) for the treatment of chronic obstructive pulmonary disease (COPD).
The lower dose 250/50 was approved for COPD treatment in the US in 2003, while the UK equivalent Seretide has been approved at the higher dose in the EU since 2003.
The 500/50 dose is currently approved in the US for the treatment of asthma.
The FDA told GSK that the data submitted, based on the TORCH (TOward a Revolution in COPD Health) study, was insufficient in determining the risk/benefit portfolio of the higher strength versus the lower strength, GSK spokeswoman Claire Brough told in-PharmaTechnologist.com.
In a statement, GSK vice president of respiratory clinical development for COPD Katharine Knobil said: "We are very surprised and disappointed by this FDA decision."
The decision is a setback for the company, who had been keeping their fingers crossed for approval following the news in May that the FDA advisory committee had unanimously agreed that Advair Diskus 500/50 demonstrated a significant reduction in the risk of exacerbations in patients with COPD, and that the product provided substantial advantages over salmeterol in the treatment of patients with COPD.
While the FDA does not base its decision on the advisory committee outcome, it does often take it very seriously.
However, spokeswoman Brough said the company continued to believe the higher strength offered a benefit to patients in terms of exacerbation, lung function and quality of life.
"We are confident in the benefit of the product and the data we have."
GSK will now meet with the FDA to discuss the data and determine the next steps.
At this point, no date has been set.
Advair is GSK's top selling pharma drug, raking in £3.3bn (€4.9bn) in 2006, which was up 11 per cent on the previous year.
Advair is currently indicated for the treatment of asthma and COPD and is available in three formulations - 100/50, 250/50 and 500/50.
Each strength contains 50mcg of salmterol, a bronchodilator of the beta-2 agonist type, but differing amounts of fluticasone propionate, an anti-inflammatory corticosteroid.
The Supplemental Drug Application was based on the results of TORCH, the largest COPD study conducted in more than 6,000 patients over three years.
The review also looked at supporting studies.
COPD is a progressive, life-threatening lung disease that primarily includes chronic bronchitis and emphysema.
COPD affects as many as 20 million Americans and is a major cause of illness, death and the use of health care resources.