FDA advisory committee backs safety and efficacy of Gilead's aztreonam for cystic fibrosis

The Anti-Infective Drugs Advisory Committee of the US Food and Drug Administration (FDA) has recommended that Gilead Sciences' aztreonam for inhalation solution be approved for the treatment of infections due to Pseudomonas aeruginosa in patients with cystic fibrosis (CF). This is a positive development for Gilead, which had this drug rejected by the FDA around a year ago, when the agency called for additional data.

The committee voted 15 to 2that Gilead has provided sufficient evidence of the safety and efficacy of aztreonam for inhalation solution. And 17 to 0 that 75mg three times daily of the drug is a correct dose and regimen.

Aztreonam sales could reach at least $200 million globally by 2015, according to Summer Street Research analyst Carol Werther, who noted that the drug could strengthen Gilead's pulmonary franchise but pales in importance when compared with its stable of HIV drugs.

The FDA has established a target review date, under the Prescription Drug User Fee Act (PDUFA), of February 13, 2010. In the interim, Gilead says it will continue to make the product available through its Expanded Access Program in the USA.

"Effectively treating infections in patients with CF is very challenging, and new treatment options are urgently needed," said Norbert Bischofberger, executive vice president, R&D and chief scientific officer, at Gilead Sciences.

Gilead originally submitted the New Drug Application for the potential product in November 2007. In September 2009, the product was granted conditional marketing approval in Canada and the European Union under the trade name Cayston (aztreonam lysine 75mg powder and solvent for nebulizer solution). Applications for marketing approval of Cayston are also pending in Australia, Switzerland and Turkey, the firm noted.

CF is a chronic, debilitating genetic disease that affects the respiratory and digestive systems of approximately 70,000 people worldwide. Chronic pulmonary infections due to P. aeruginosa are the single greatest cause of morbidity and mortality among patients with CF.