The first study examined the effects of linaclotide in patients with chronic constipation (CC), while the second study examined its effects in patients with irritable bowel syndrome with constipation (IBS-C). Preliminary analysis of the CC study data and an interim analysis of the IBS-C study data indicate that each study met its primary endpoint.
In the four-week CC study, the primary efficacy endpoint was the change from pre-treatment in weekly spontaneous bowel movement (SBM) frequency rate. During the two-week pre-treatment period, the mean baseline weekly SBM frequency rate across all treatment groups was 2.31. Patients who received once-daily dosing of linaclotide demonstrated a dose-responsive increase in weekly SBM frequency rate ranging from 0.98 (75mcg, p = 0.09) to 2.99 (600mcg, p < 0.0001) compared to patients receiving placebo. The response was significant at all doses above 75mcg. Patients with IBS-C who received once-daily treatment with linaclotide experienced a significant increase in weekly complete spontaneous bowel movement frequency rate - the primary endpoint for this study - at all doses except for 15mcg.