Safety and Efficacy of Mirabegron: Analysis of a Large Integrated Clinical Trial Database of Patients with Overactive Bladder Receiving Mirabegron, Antimuscarinics, or Placebo.

BACKGROUND: Mirabegron, a β3-adrenoreceptor agonist, is an alternative drug to antimuscarinics for overactive bladder (OAB) symptoms.

OBJECTIVE: To summarise safety and efficacy reporting of mirabegron treatment for OAB symptoms.

DESIGN, SETTING, AND PARTICIPANTS: Pooled data analysed from 10 phase 2-4, double-blind, 12-wk mirabegron monotherapy studies in adults with OAB who had received one or more doses of study drug.

INTERVENTION: Mirabegron: 25 and 50mg; antimuscarinics: solifenacin (2.5, 5, and 10mg) and tolterodine extended release (4mg).

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Baseline OAB-related characteristics, intrinsic and extrinsic factors, and analyses by age (<65 vs ≥65yr and <75 vs ≥75yr) and sex were assessed. Solifenacin 2.5 and 10mg groups were not included in the efficacy analyses (small patient numbers). Safety was evaluated using the proportion of treatment-emergent adverse events. Efficacy variables were derived from bladder diaries (baseline and week 12).

RESULTS AND LIMITATIONS: Baseline hypertension and diabetes were more frequent across treatment groups in the older versus younger age groups and in men versus women. Within sexes, frequencies were similar between treatment groups. Some differences were observed in baseline characteristics, including type of incontinence and medical history between sexes. No previously unreported safety concerns were identified. Improvements in efficacy (mean number of incontinence episodes/24h, micturitions/24h, urgency episodes/24h, volume voided/micturition, and nocturia episodes) versus placebo were observed in all treatment groups. Significant treatment-by-subgroup interactions included change from baseline in the mean number of incontinence episodes/24h by age (<65 vs ≥65yr), nocturia by age (<65 vs ≥65yr and <75 vs ≥75yr), and urgency episodes by previous OAB medication.

CONCLUSIONS: Data from this integrated database of 10 mirabegron studies reaffirm the safety and efficacy profiles of mirabegron, solifenacin, and tolterodine in adults of different age groups and sexes.

PATIENT SUMMARY: Overactive bladder is a complex of symptoms including a compelling desire to pass urine that leads to increased frequency, which may lead to a degree of incontinence if you do not reach the toilet in time and may wake you from sleep. We pooled data from 10 different studies of mirabegron in patients with overactive bladder symptoms, and looked at the effect in the total number of patients who received the treatment, as well as in different age groups and between men and women. No new safety concerns were identified, and mirabegron improved the symptoms of overactive bladder.