Ironwood Pharmaceuticals, Inc. announced positive topline data from a Phase III clinical trial evaluating LINZESS (linaclotide) 72 mcg in pediatric patients aged 6-17 with functional constipation (FC). The trial met its primary and secondary endpoints, demonstrating that linaclotide (72 mcg) improved frequency of spontaneous bowl movements (SBM) and stool consistency. Linaclotide was generally well-tolerated, and the safety profile is consistent with previously reported studies with linaclotide in FC and irritable bowel syndrome (IBS) in pediatric patients.

In this study, a total of 330 patients were randomized in a 1:1 ratio between linaclotide or placebo. Topline data indicate that linaclotide showed a statistically significant and clinically meaningful improvement compared to placebo in 12-week SBM frequency rate (SBMs/week), the primary endpoint. Linaclotide-treated patients demonstrated a greater than two-fold least squares mean change from baseline in SBMs/week (2.220) compared to placebo (1.050) (p<0.0001).

Stool consistency, as assessed by Bristol Stool Form Scale (BSFS) scores, which was the secondary endpoint, also showed an improvement at weeks 12 with linaclotide compared to placebo. The least squares mean change from baseline at week 12 was 1.108 and 0.685 points, respectively (p=0.0001). The BSFS is a 7-point scale ranging from 1 (separate hard, difficult-to-pass lumps) to 7 (liquid stools).

Overall, linaclotide (72 mcg) was well tolerated. The most frequently reported treatment-emergent adverse event was diarrhea, which occurred in 4.3% of linaclotide-treated participants versus 1.8% in the placebo group. These data are from the FC cohort of the Phase III, multicenter, randomized, double-blind, parallel-group, safety, and efficacy study of linaclotide vs.

placebo in children ages 6-17 years with FC. Participants in the FC cohort must have fulfilled modified Rome III Criteria for child/adolescent FC. Ironwood expects to share these Phase III trial data at upcoming scientific meetings and via peer-reviewed publications.

LINZESS is developed and marketed by Ironwood and AbbVie in the United States and is indicated for the treatment of adults with IBS-C or CIC. It is not approved for use in patients less than 18 years of age.