Linaclotide Is Effective for Irritable Bowel Syndrome with Constipation

In recent phase IIb studies, linaclotide was effective in the treatment of constipation-predominant irritable bowel syndrome (IBS-C; Gastroenterology 2007; 133:761 and Gastroenterology 2010; 139:1877). Now, results of two phase III trials are reported.

Both industry-supported studies were placebo-controlled, double-blind trials in which investigators randomized patients with IBS-C to receive 290 µg of oral linaclotide or placebo once daily. The primary endpoint in each study was an improvement of ≥30% from baseline in the average daily worst abdominal pain score and an increase from baseline of ≥1 complete spontaneous bowel movement, both in the same week, for ≥6 of 12 weeks of treatment.

In the first trial, 804 patients (mean age, 44; 90% wo…