A Study to Evaluate the Effect of Mirabegron + Solifenacin in Overactive Bladder Patients

Safety and Efficacy of Mirabegron as Add-on Therapy in Patients With Overactive Bladder Treated With Solifenacin: A Postmarketing Open-label Study in Japan

The purpose of this study was to evaluate the safety and efficacy of mirabegron as add-on therapy in patients with OAB treated with solifenacin.

The total duration of the study was 18 weeks, comprising a 2-week screening period and a 16-week treatment period. Patients meeting the eligibility criteria for provisional enrollment received the study drug for the screening period (solifenacin) at the same dose as that before the start of the study (2.5 or 5 mg), once daily after breakfast orally for 2 weeks. After the screening period, patients meeting the eligibility criteria for formal enrollment received the study drugs for the treatment period (solifenacin 2.5 or 5 mg and mirabegron 25 mg), once daily after breakfast orally for 16 weeks. Mirabegron dose could be increased to 50 mg at week 8 visit if the patients met all of the following criteria: (1) had an inadequate response to mirabegron at the dose of 25 mg; (2) was judged by the investigator or coinvestigator to have no safety concerns; and (3) agreed to increase the dose.

Inclusion Criteria:

• Female: postmenopausal OAB outpatient
• Male: OAB outpatient who did not wish to have children at all
• Patient had been treated with solifenacin at a stable dose once daily for at least 4 weeks prior to the study
• Patient had a total OAB symptom score (OABSS ) score of ≥3 points and a Question 3 score ≥2 points

Exclusion Criteria:

• Patient had a residual urine volume of ≥100 mL or a maximum flow rate <5 mL/s, or patients with benign prostatic hyperplasia, or lower urinary tract obstruction
• Patient had serious heart disease (myocardial infarction, cardiac failure, uncontrolled angina pectoris, serious arrhythmia, use of pacemaker, etc.), liver disease, kidney disease, immunological disease, lung disease, etc. or patient had malignant tumor (except for malignant tumor that has not been treated for at least 5 y before the start of the screening period with no risk of recurrence)
• Patient had received surgical therapy that may affect the urinary tract function within 24 weeks before the start of the screening period