Ironwood Pharmaceuticals has commenced a Phase IIIb clinical trial to examine the efficacy and safety of linaclotide for the treatment of adult patients with irritable bowel syndrome with constipation (IBS-C).
The randomised, double-blind, placebo-controlled, parallel-group trial is expected to evaluate linaclotide at 290mcg on various bothersome abdominal symptoms associated with IBS-C, including bloating, discomfort and pain.
As part of the trial, around 600 IBS-C patients will be randomised to receive placebo or linaclotide at 290mcg once daily for 12 weeks, followed by a four-week randomised withdrawal period.
The trial’s primary efficacy objective is change from baseline in abdominal score based on daily patient assessments of abdominal bloating, discomfort, and pain at their worst, as measured by an 11-point numerical rating scale.
Its additional endpoints comprise change from baseline in spontaneous bowel movement (SBM) frequency, complete spontaneous bowel movement (CSBM) frequency, stool consistency, and straining.
The trial is being carried out by Ironwood in collaboration with Allergan in the US.
Ironwood Pharmaceuticals senior vice-president, global development and chief development officer Christopher Wright said: “There are an estimated 13 million adult IBS-C patients in the US, and more than two thirds of them report suffering from symptoms such as abdominal bloating and discomfort at least once per week.
“These symptoms are often a primary complaint and reason for patients seeking care.
“As IBS-C patients often describe their abdominal symptoms as bloating or discomfort, rather than pain, this can lead to under-treatment. If positive, we believe this data should further enable more effective communication between patients and physicians on both IBS-C and the role that linaclotide can play in treating the millions of appropriate patients suffering from IBS-C.”
Linaclotide is a guanylate cyclase‐C (GC‐C) agonist designed to locally bind to the GC-C receptor within the intestinal epithelium.