Long-term safety, tolerability, and efficacy of the novel anti-muscarinic agent imidafenacin in Japanese patients with overactive bladder

Objectives: To evaluate the long-term safety, tolerability, and efficacy of imidafenacin, a novel anti-muscarinic agent, in Japanese patients with overactive bladder. Methods: Men and women who had overactive bladder symptoms were enrolled for open-label treatment with 0.1 mg of imidafenacin twice daily for 52 weeks; the safety and efficacy of the treatment regimen were assessed. Results: A total of 478 patients received the treatment and 376 patients completed the 52-week program. Imidafenacin was well tolerated, the most common adverse event being a dry mouth (40.2% of the patients). Compared with short-term treatment, long-term treatment did not produce an increase in the frequency of adverse events. Imidafenacin had no significant effects on the corrected QT interval, vital signs, results from laboratory tests, or post-void residual volume. A significant efficacy of imidafenacin was observed from week 4 through week 52. After 52 weeks, imidafenacin produced mean changes from baseline in the number of incontinence episodes (-83.51%), urgency incontinence episodes (-84.21%), voiding frequency (-2.35 micturitions/day), urgency episodes (-70.53%), and volume voided per micturition (28.99 mL). There were also significant reductions from baseline in all domains of the King's Health Questionnaire. Conclusions: Favorable safety, tolerability, and efficacy profiles for 0.1 mg of imidafenacin administered twice daily were maintained over 52 weeks in Japanese patients with overactive bladder.