Efficacy and safety of linaclotide in treatment-resistant chronic constipation: A multicenter, open-label study.

Background: This study aimed to evaluate the efficacy and safety of linaclotide in patients with chronic constipation (CC) or irritable bowel syndrome with constipation (IBS-C) who did not respond to treatment with magnesium oxide (MgO).

Methods: This study was designed as a multicenter, open-label, single-arm, exploratory study. Patients with CC or IBS-C who took MgO and those meeting the medication initiation criteria were administered linaclotide at a daily dosage of 500 μg for 12 weeks. The primary endpoint was a change in the Japanese version of the Patient Assessment of Constipation Quality of Life (JPAC-QOL) score from baseline, which was evaluated by using a paired t-test.

Key Results: The patients' mean age (± standard deviation) was 67.6 ± 13.82 years. The full analysis set included 61 patients. The JPAC-QOL total score was 1.60 at baseline and 0.70 at 12 weeks, with a significant mean change of -0.89 ± 0.721 (p < 0.001). Several secondary endpoints also showed improvement. The frequency of spontaneous bowel movement (SBM) and complete SBM increased by 2.70 ± 7.254 (p < 0.01) and 2.81 ± 5.254 times, respectively (p < 0.001). The Bristol Stool Form Scale, abdominal bloating severity, and straining severity scores improved by 1.33 ± 1.274 (p < 0.001), -0.16 ± 0.563 (p < 0.05), and -0.46 ± 0.795 (p < 0.001) points, respectively. The safety analysis set included 65 patients, 7 of whom had diarrhea, which improved with dose reduction and drug withdrawal.

Conclusion & Inferences: The study was conducted in an older adult population, similar to real clinical practice. Linaclotide may be an option for treating CC that shows an inadequate response to conventional therapy.