Amitiza benefited patients with chronic idiopathic constipation
Amitiza, a novel type 2 chloride channel activator, increased the frequency of spontaneous bowel movement and quality of life in patients with chronic idiopathic constipation, according to phase 3 trial data.
Aiming to confirm the safety and efficacy of Amitiza (lubiprostone, Sucampo Pharmaceuticals) in Japanese patients with chronic idiopathic constipation, researchers performed a randomized, double blind, placebo-controlled trial involving 124 patients from 11 centers with chronic idiopathic constipation who received either 48 µg/day lubiprostone or placebo for 4 weeks. A second component of the study was a nonmasked long-term safety trial involving 209 patients with chronic idiopathic constipation at 17 centers who received 24 µg lubiprostone twice a day for 48 weeks. Patients completed a daily diary and questionnaires to report spontaneous bowel movement frequency and symptoms.
In the first part of the study, lubiprostone increased weekly average number of spontaneous bowel movements at week 1 (3.7 ± 2.8) compared with placebo (1.3 ± 1.8; P < .001), and patients reported greater changes from baseline in week 2 (P < .001), week 3 (P = .005) and week 4 (P = .042). The proportion of patients who reported first spontaneous bowel movement within 24 hours of taking lubiprostone was higher compared with placebo (P = .004), time to first spontaneous bowel movement was shorter (P = .027), and the proportion of patients who reported four or more spontaneous bowel movements during the first week was higher (75.4% vs. 29%; P < .001). Patients in the lubiprostone group also had better outcomes in constipation severity, treatment effectiveness and stool consistency.
In the second part of the study, frequency of spontaneous bowel movements increased compared with baseline in the lubiprostone group at all weeks throughout the study period (P < .0001). Irritable bowel syndrome quality of life (QOL) scores were increased at weeks 24 and 48 compared with baseline (both P < .0001) and significant increases in Short-Form health survey scores were also observed.
In the first part of the study, lubiprostone patients had more adverse drug reactions compared with placebo (41.9% vs. 16.1%; P = .003), but most were mild (diarrhea, P = .003; nausea, P = .017). In the second part of the study, 73.2% reported adverse drug reactions. No related severe adverse events were observed.
“In conclusion, lubiprostone 48 µg/d (24 µg twice daily) showed statistically significant and clinically meaningful improvements in constipation signs and symptoms in patients with [chronic idiopathic constipation], and was associated further with a favorable safety and tolerability profile in a Japanese population,” the researchers wrote. “Results from these studies also suggest that lubiprostone improves health-related QOL in patients with [chronic idiopathic constipation] with long-term use.” – by Adam Leitenberger
Disclosure: This trial was funded by Sucampo Pharma. Fukudo and other researchers report being paid consultants for Sucampo Pharma, and another researcher reports being a former director of Sucampo AG, a former employee of Sucampo Pharma Americas and a current shareholder of Sucampo Pharmaceuticals.