A European Medicines Agency committee has decided not to back the use of Swiss drug giant Novartis’ Zelnorm (tegaserod maleate) for the treatment of women with irritable bowel syndrome-induced constipation, even though the agent is currently used in 56 countries across the globe, including the USA.

Novartis said it will appeal the decision, and maintained that it is still committed to the drug, which made sales of $299 million last year. “Although we are disappointed with the [European Committee for Medicinal Products for Human Use] opinion, we are confident in the clinical profile and benefits of Zelnorm,” stated James Shannon, head of global pharmaceuticals development at Novartis. He also noted that Zelnorm “has been rigorously studied in more than seven placebo-controlled trials involving over 14,000 patients worldwide.”

But investors were a little less confident, as the group’s New York Stock Exchange-traded shares dropped just over 2% to $53.32 on the news, which marks another blot on the product’s already chequered landscape.

Since an approvable letter from the US regulatory authorities in 2001 pushed back Zelnorm’s first launch to the following year, the drug has been hit with safety concerns, leading the US Food and Drug Administration to slap a heavier warning on its label regarding an increased risk of serious diarrhoea and a condition where blood flow to the intestines is hampered.

But industry observers still feel that Zelnorm has the potential to do very well, even though it is taking longer than expected to get there.