A Study to Evaluate the Efficacy, Safety, and Tolerability of Mirabegron in Men With OAB Symptoms While Taking Tamsulosin Hydrochloride for Lower Urinary Tract Symptoms (LUTS) Due to Benign Prostatic Hyperplasia (BPH)

At Screening (Visit 1), participants entered into a 4-week open label tamsulosin hydrochloride 0.4 mg QD run-in period prior to being randomized into the 12-week double-blind treatment period (Visit 2). At conclusion of the 4-week tamsulosin hydrochloride run-in period, participants completed a 3-day diary just prior to Baseline (Visit 2). Approximately 7 days prior to Visit 2 participants received a phone call reminding them about the diary and to answer any questions.

If participants met all entry criteria at the end of the tamsulosin hydrochloride run-in period, participants were randomized to 1 of 2 treatment groups (mirabegron or placebo) for 12 weeks of treatment in addition to the continuation of tamsulosin hydrochloride 0.4 mg QD. Those participants randomized to Mirabegron started at 25 mg and increased to 50 mg after 4 weeks. Those participants randomized to placebo started blinded product matched to the mirabegron 25 mg tablet and increased to blinded product matched to 50 mirabegron after 4 weeks. Once a participant increased dose, the participant remained on that dose for the remainder of the study unless for safety reasons was required to discontinue study drug.

A training diary was completed in the first 2 weeks of the tamsulosin hydrochloride run-in period. During this evaluation period at least one telephone contact took place with the participant. Diaries were completed at home, using the electronic patient-reported outcome (ePRO) device, for 3 consecutive days prior to each visit: Baseline (Visit 2), Week 4 (Visit 3), Week 8 (Visit 4), and Week 12/End of Treatment (Visit 5). Site staff contacted the participant approximately 7 days prior to the scheduled visit to remind the participant to complete the electronic diary, review completion instruction and review changes to concomitant medications and adverse events (if applicable).

Three days before Visits 2 (Baseline), 3 (Week 4), 4 (Week 8), and 5 (Week 12), participants completed a 3-day diary, using the ePRO device in which the participant recorded micturition frequency, urgency (PPIUS), incontinence and volume voided. In addition, the diary captured morning and evening blood pressure and pulse rate measurements via Home Blood Pressure Monitoring (HBPM). At Visit 1, International Prostate Symptom Score (IPSS) was completed. At Visits 2, 3, 4, and 5, participants completed the IPSS, EQ-5D-5L, OAB-q, PPBC, and TS-VAS. Maximum urinary flow (Qmax) was measured at Visit 1 (Screening/tamsulosin hydrochloride run-in) and Visit 5 (Week 12/End of Treatment). Post-void residual volume (PVR) was assessed at Screening/tamsulosin hydrochloride run-in (Visit 1), Baseline (Visit 2) and at Week 4 (Visit 3), Week 8 (Visit 4), and Week 12/End of Treatment (Visit 5). A follow-up phone call (Visit 6) was conducted 4-weeks after End of Treatment (Visit 5). Total study participation was approximately 20 weeks.