Treating Overactive Bladder in Older Patients with a Combination of Mirabegron and Solifenacin: A Prespecified Analysis from the BESIDE Study

Abstract

Background: The BESIDE study demonstrated that combination therapy (mirabegron and solifenacin 5mg) improved overactive bladder symptoms versus solifenacin 5mg or 10mg, and was well tolerated.

Objective: To ensure efficacy and safety is maintained in older patients (>65 yr), who usually experience greater symptom severity and comorbidities, a prespecified subanalysis stratified by age group was conducted.

Design, setting, and participants: Patients remaining incontinent (≥1 episode during 3-d diary) following 4-wk single-blind daily solifenacin 5mg were randomized 1:1:1 to a daily double-blind combination (solifenacin 5mg and mirabegron 25mg, increased to 50mg at wk 4), solifenacin 5mg or 10mg for 12 wk. Four cohorts stratified by age (<65 yr, ≥65 yr and < 75 yr, ≥75 yr) were investigated.

Outcome measurements and statistical analysis: Efficacy assessments: change from baseline to end of treatment in average daily incontinence (primary) and micturition frequency (key secondary), number of incontinence episodes during the 3-d diary (key secondary), and change from baseline in average daily urgency and urgency incontinence episodes. Safety included treatment-emergent adverse events and vital signs.

Results and limitations: Full analysis set included 2110 patients: 30.9% aged ≥65 yr and 8.9% aged ≥75 yr. At the end of treatment, daily, and 3-d incontinence daily micturitions, urgency, and urgency incontinence, were improved in each treatment group and age group; the largest reductions were observed with combination in each age cohort. There were no notable differences in vital signs or the incidence of treatment-emergent adverse events between treatment and age groups, with the exception of dry mouth, which was highest with solifenacin 10mg.

Conclusions: Efficacy and safety in the overall population is maintained in older (≥65 yr) and elderly (≥75 yr) patients treated with a combination of solifenacin and mirabegron, or solifenacin monotherapy; irrespective of age, combination was associated with the greatest improvement in overactive bladder symptoms.

Patient summary: This study investigated the effectiveness and safety of a combination of two different treatments (mirabegron 50mg and solifenacin 5mg) or solifenacin (5mg or 10mg) alone in patients aged <65 yr or ≥65 yr, and <75 yr or ≥75 yr with overactive bladder. Symptoms of overactive bladder, such as the urgent need to visit the toilet, incontinence, and frequent urination, were improved with all treatments regardless of the patient's age, but combination treatment demonstrated the greatest benefit, and was well tolerated.

Trial registration: ClinicalTrials.gov NCT01908829.

Keywords: Add-on therapy; Aged; Incontinence; Mirabegron; Overactive bladder; Solifenacin.