Phase II Study on the Efficacy and Safety of the EP1 Receptor Antagonist ONO-8539 for Nonneurogenic Overactive Bladder Syndrome

Purpose: We evaluated the efficacy, safety and tolerability of the EP1 receptor antagonist ONO-8539 in patients with overactive bladder syndrome.Materials and Methods: This was a 12-week, randomized, double-blind, placebo controlled, parallel group, multicenter study with a 2-week single blind placebo run-in phase. The 435 patients were randomized to receive twice daily ONO-8539 (30, 100 or 300 mg), placebo or once daily tolterodine (4 mg).Results: At the end of the 12-week treatment no statistically significant difference was found between ONO-8539 and placebo in the change from baseline in the number of micturitions per 24 hours. The primary end points for 30, 100 and 300 mg ONO-8539, and placebo were –1.02, –1.53, –1.31 and –1.40, respectively. There was no statistically significant difference between any ONO-8539 group and placebo in the change from baseline in the number of urgency or urinary urgency incontinence episodes per 24 hours, or the mean volume voided per micturition, which were secondary e...