A new treatment for irritable bowel syndrome could soon be available if Sucampo, a partner of Japan’s Takeda, succeeds in getting a new indication approved by US regulators for its chronic constipation drug Amitiza.

Sucampo, which is based in Maryland, USA, has submitted a supplemental New Drug Application to the US Food and Drug Administration to seek market approval of a lower strength (8mcg) of Amitiza (lubiprostone) to treat irritable bowel syndrome with constipation. The drug is currently approved for the treatment of chronic idiopathic constipation in adults with a 24mcg dose and is co-marketed in the USA by Sucampo and Takeda.

The supplemental application is based on two Phase III studies, in wich patients received lubiprostone 8mcg taken twice daily (783 adults) or placebo (388) over a 12-week period. In both trials, patients receiving Sucampo’s drug were nearly twice as likely to achieve an overall response that was statistically significant compared to those receiving placebo.

Approximately 58 million Americans have irritable bowel syndrome, with IBS-C accounting for approximately one-third of these cases and the market has opened up since the FDA asked Novartis to suspend US marketing of its IBS drug Zelnorm/Zelmac (tegaserod) in April. This followed fears raised by the agency that the Swiss firm’s treatment could be linked to heart attacks and strokes.