Ironwood Pharmaceuticals and Allergan have announced that a Phase IIIb clinical trial has met its primary multi-component endpoint in evaluating the safety and efficacy of LINZESS (linaclotide) on multiple abdominal symptoms in adult patients with IBS-C.

The randomised, double-blind, placebo-controlled Phase IIIb trial also demonstrated that linaclotide 290 mcg, when administered orally once daily, improved the overall abdominal symptoms of bloating, pain and discomfort in adults with IBS-C when compared to placebo.

Both secondary endpoints were also met in the trial, which was designed to highlight the impact of LINZESS on the overall abdominal symptoms.

The primary efficacy endpoint was a change from baseline in abdominal score based on daily patient assessments of abdominal symptoms at their worst.

The trial saw a total of 614 patients randomised to placebo or LINZESS 290 mcg once daily for 12 weeks, followed by a four-week randomised withdrawal period.

Marketed by Ironwood and Allergan in the US, LINZESS is indicated to treat adults with IBS-C or chronic idiopathic constipation (CIC).

Ironwood Pharmaceuticals chief medical officer, senior vice-president and Drug Development head Mike Shetzline said: “These topline results demonstrated that LINZESS can help provide overall relief of some of the multiple abdominal symptoms that IBS-C patients identify as among the most bothersome.

“As the tenth Phase III trial of linaclotide to meet its primary endpoint, this study further contributes to the robust body of evidence supporting the use of LINZESS in adults with IBS-C and further strengthens its clinical profile.”

In the multi-component primary endpoint, patients treated with linaclotide reported a 29.7% mean decrease from baseline in their weekly abdominal score.

In the secondary endpoints, 40.5% of patients treated with the guanylate cyclase-C (GC-C) agonist demonstrated a clinically meaningful response, as defined by the abdominal symptom score responder.