FDA filings for Ironwood and Forest for linaclotide, and GSK and XenoPort for Horizant ER

US drugmakers Ironwood Pharmaceuticals (Nasdaq: IRWD) and Forest Laboratories (NYSE: FRX) have submitted a New Drug Application to the US Food and Drug Administration for linaclotide, a guanylate cyclase type-C (GC-C) agonist, for the treatment of irritable bowel syndrome with constipation (IBS-C) and chronic constipation (CC).

The submission includes efficacy and safety data from a Phase III program comprising four double-blind placebo-controlled trials and two open-label long term safety studies. A total of more than 2,800 patients received a once-daily dose of either linaclotide or placebo across the four placebo-controlled clinical trials: two trials in patients with IBS-C and two trials in patients with CC. In these trials, statistically significant improvements in abdominal and bowel symptoms were achieved for linaclotide-treated patients versus placebo-treated patients for all primary and secondary endpoints.

Safety data collected across the four placebo-controlled Phase III clinical trials demonstrated that diarrhea was the most commonly reported adverse event and led to study discontinuation in 4% to 5% of linaclotide-treated patients compared to fewer than 1% of those receiving placebo. Additionally, over 3,200 subjects have enrolled in ongoing open-label safety studies and more than 1,100 of those patients have received linaclotide for at least 12 months.