Effectiveness and Safety of Mirabek Sustained-release 50 mg Tablets in Korean Patients with Overactive Bladder: A Multicenter Observational Study at Tertiary General Hospitals

Abstract

Background and objective: Mirabegron, a first-in-class β3-adrenergic agonist, is a key therapy for overactive bladder (OAB). This study aimed to evaluate the real-world effectiveness and safety of generic mirabegron (Mirabek) in Korean patients with OAB through a multicenter, prospective, noninterventional observational study at tertiary general hospitals.

Methods: Adult patients with OAB newly prescribed Mirabek sustained-release 50 mg tablets were enrolled from 46 tertiary general hospitals. Assessments were performed at baseline and follow-up visits at 3 and 6 mo. Data collected included the OAB Symptom Score (OABSS), bladder diaries, uroflowmetry results, and adverse events.

Key findings and limitations: Among the 4009 participants analyzed, 81.3% completed 6 mo of treatment. At 3 and 6 mo, 35.3% and 43.4% of participants, respectively, achieved a ≥3-point reduction in total OABSS (p < 0.0001), with the mean score improving from 6.9 to 4.6. All seven bladder diary parameters, including urgency and incontinence, showed significant improvement. Treatment satisfaction increased, and 67.3% of participants continued Mirabek at 6 mo. Adverse events occurred in 5.5% of participants, with 1.8% being drug related; all were mild.

Conclusions and clinical implications: Mirabek (generic mirabegron) demonstrated effective symptom relief and was well tolerated in Korean patients with OAB, with sustained efficacy up to 6 mo. The introduction of Mirabek substantially reduced treatment costs and expanded access to mirabegron therapy.

Patient summary: In this study, we looked at the effect of Mirabek, a generic medication for overactive bladder (OAB), in >4000 Korean patients treated in large hospitals. We found that Mirabek improved bladder symptoms such as urgency and frequent urination over 6 mo, with very few side effects. Most patients stayed on the treatment and reported feeling better, suggesting that this affordable medication can help more people manage their OAB effectively.