Comparative Efficacy and Safety of the β3-Adrenoceptor Agonist Vibegron for Urgency and Mixed Urinary Incontinence: A Post Hoc Analysis of a Randomized, Double-Blind, Placebo-Controlled Phase 3 Study

Objective To compare the efficacy of vibegron for urgency urinary incontinence (UUI) and mixed urinary incontinence (MUI) in patients with overactive bladder (OAB). Methods We performed a post hoc analysis of a phase 3 study of vibegron in Japanese patients with OAB. Based on the patterns recorded in the three-day bladder diary, only female patients were categorized into UUI and MUI populations. The primary endpoint was the change in the mean micturition number per 24 hours from baseline to week 12. Other endpoints included the mean changes in urgency episodes per 24 hours, incontinence episodes per 24 hours, voided volume per micturition, and the number of nocturia episodes per night. The proportion of urinary incontinence (UI) normalization, quality of life (QOL) as measured by the King's Health Questionnaire (KHQ), and patient satisfaction level as assessed by the Patient Global Impression (PGI) were investigated. Result Data from a UUI population (vibegron 50 mg, n = 237; vibegron 100 mg, n = 231; placebo, n = 237) and an MUI population (vibegron 50 mg, n = 70; vibegron 100 mg, n = 77; placebo, n = 78) were analyzed. Vibegron 50 mg and 100 mg significantly improved the change in micturition number per 24 hours from baseline to week 12. Compared to those of patients receiving a placebo, all other endpoints of urinary parameters were significantly improved in patients receiving vibegron, except for nocturia in the vibegron 50 mg group in both populations. In the vibegron 50 mg, vibegron 100 mg, and placebo groups, the proportions of those who attained normalization of UI were stratified by the UUI (51.5%, 57.6%, and 44.7%, respectively) and MUI (40.0%, 41.6%, and 20.5%, respectively) populations. Furthermore, both vibegron doses improved KHQ scores in both populations, and PGI improvement was significantly higher than that in the placebo group in both populations. Conclusion This post hoc analysis demonstrated that vibegron has equivalent efficacy and safety in the MUI and UUI populations. The results of this study provide important information for the treatment of MUI.