Belgian company, Solvay, says that it has received a not approvable letter from the US Food and Drug Administration for its irritable bowel syndrome drug, cilansetron.

A brief press release from the firm revealed that the agency had asked for more clinical trials on the drug, which has been filed as a possible treatment for diarrhoea-predominant IBS in both men and women [[02/09/04c]], [[02/07/04c]]. Solvay says that it is examining its options and will discuss future steps with the FDA.

The news is the latest in a long line of blows for IBS drugs. The FDA has had its fingers burned in the past with products to treat this condition after GlaxoSmithKline’s Lotronex (alosetron) was withdrawn in 2000 after less than one year on the market following reports of ischaemic colitis and severe constipation, including three fatalities. The drug has since been reintroduced – albeit with a restricted label [[21/11/02c]]. Solvay has played down concerns of ischaemic colitis amongst cilansetron-treated patients, saying that all cases have been resolved without complications. The company has highlighted the fact that IBS patients are generally at an increased risk of developing ischaemic colitis, and included a drug user programme, including educational tools [[20/05/04f]].