Phase III trial of Linzess (linaclotide) in chronic constipation meets primary endpoint- Astellas Pharma and Ironwood Pharmaceuticals

Astellas Pharma and Ironwood Pharmaceuticals announced top-line results indicating that the Phase III clinical trial of Linzess (linaclotide) conducted in Japan in adults with chronic constipation (CC) met its primary endpoint. The double-blind, placebo-controlled Phase III clinical trial randomized 186 adults with CC in Japan to receive either 500 mcg of linaclotide or placebo for 4 weeks (1:1 ratio). The top-line trial results indicate that linaclotide-treated patients showed statistically significant improvement compared to placebo-treated patients for the primary endpoint, change from baseline in mean spontaneous bowel movement frequency at Week 1. The most common adverse event reported in this trial was diarrhea. All cases of diarrhea were characterized as mild or moderate in severity.

Patients in the Phase III CC trial in Japan continue to receive open-label linaclotide for an additional 52 weeks; the blinded efficacy data coupled with these open-label safety data are expected to form the basis for regulatory review and potential approval for this indication in Japan. Further detailed results from the Phase III trial are expected to be presented at an upcoming scientific meeting.

Comment: Linaclotide is approved in Japan as the first prescription treatment for adults with irritable bowel syndrome with constipation (IBS-C). Linaclotide is currently approved in the United States for the treatment of adults with IBS-C or chronic idiopathic constipation (CIC). It is also approved for adults with IBS-C or CIC in more than 30 other countries.