Mirabegron Add-On Therapy to Tamsulosin in Men with Overactive Bladder: Post Hoc Analyses of Efficacy from the MATCH Study

INTRODUCTION: MATCH was a randomized, double-blind, placebo-controlled study enrolling Japanese and Korean men aged ≥ 40 years who still had overactive bladder (OAB) symptoms while receiving tamsulosin. After a 4-week single-blind screening period in which patients received placebo and tamsulosin, patients were randomized to mirabegron 50 mg + tamsulosin or placebo + tamsulosin for 12 weeks (n = 568). This post hoc analysis investigated the proportion of treatment responders for each treatment group and for subgroups stratified by age based on voiding diaries and patient-reported outcomes (PROs). METHODS: Responders were defined as those achieving normalization or clinically meaningful improvements in efficacy, or clinically important differences in PROs [≥ 10-point improvement in OAB questionnaire (OAB-q) symptom bother or total health-related quality of life (HRQoL) subscales at end of treatment (EoT; minimally important difference [MID]) or OAB symptom score (OABSS) total score decreased by ≥ 3 points at EoT [minimally clinically important change (MCIC)]]. RESULTS: At EoT, micturition frequency normalization was achieved by 30.7% of tamsulosin + mirabegron patients and 18.6% of tamsulosin + placebo patients. Normalization of urgency and incontinence was 19.1% and 60.7% for tamsulosin + mirabegron and 18.2% and 60.0% for tamsulosin + placebo. Normalization of OAB symptoms based on OABSS was 17.1% for tamsulosin + mirabegron and 14.5% for tamsulosin + placebo. Higher proportions of patients in the mirabegron add-on group versus the placebo group reported clinically meaningful improvements in micturitions, urgency, and incontinence and in MCIC for OABSS and MID for the OAB-q subscales. Double- and triple-responder findings were as predicted by the results of single-responder analyses. These results were mirrored in the age groups using cut-offs of 65 and 75 years. CONCLUSION: Mirabegron therapy added on to tamsulosin resulted in a higher frequency of responders in terms of normalization (e.g., micturition frequency normalization), clinically meaningful improvements in efficacy (e.g., ≥ 50% decrease in urgency), and minimally important changes in PROs (e.g., MCIC in OABSS). TRIAL REGISTRATION: ClinicalTrials.gov identifier, NCT02656173.