Extended analysis of a double-blind, placebo-controlled, 15-week study with otilonium bromide in irritable bowel syndrome

Background/objective In order to follow the most recent developments and recommendations in trial methodology for drug evaluation in patients with irritable bowel syndrome, we performed an extended analysis of a large clinical trial from a previously published study of otilonium bromide, using an assessment that integrates the key symptoms of irritable bowel syndrome. Materials and methods A large-scale clinical trial with a double-blind, placebo-controlled, parallel-group study design was conducted in 378 patients, treated for 15 weeks with the recommended standard dose of 40 mg otilonium bromide or placebo three times daily. The study was based on the collection of 12 single efficacy endpoints. The new efficacy assessment was based on the data reported by the patients. Rather than demonstrating score differences between the treatment groups of the study, we carried out an assessment that integrates the most frequent symptoms reported (pain frequency and intensity, presence of meteorism and distension) by the patient. Results The rate of response to treatment within 24 months (the primary efficacy outcome measure) was significantly higher in the otilonium bromide group (36.9%) than in the placebo group (22.5%; P = 0.007). In each month of treatment, the rate of monthly response was higher in the otilonium bromide group as compared to the placebo group (P < 0.05). The total monthly and weekly responses to the single endpoints (intensity and frequency of pain and discomfort, meteorism/abdominal distension, severity of diarrhoea or constipation and mucus in the stool) were significantly more frequent in the group treated with otilonium bromide than in the placebo-treated group, with differences ranging from 10% to 20%. The subgroup analysis of the intestinal habits endpoint indicates that patients with diarrhoea have an additional benefit. Conclusion The present re-evaluation of a previously published study confirms that otilonium bromide is more effective than placebo for the treatment of irritable bowel syndrome, being very efficient in relieving pain and discomfort.