Interpretation of the Meaningfulness of Symptom Reduction with Vibegron in Patients with Overactive Bladder: Analyses from EMPOWUR.

Introduction: Reductions in bothersome symptoms of overactive bladder (OAB) demonstrate improvement in clinical trials, but patient perception of meaningfulness of such improvement is lacking. In the 12-week phase 3 EMPOWUR trial, vibegron significantly reduced average daily number of micturitions, urgency episodes, and urge urinary incontinence (UUI) episodes vs placebo (P < 0.01 each). This analysis assessed meaningfulness of reductions in clinical endpoints observed in EMPOWUR using patient perception of improvement.
Methods: An anchor-based approach using Patient Global Impression of Change (PGI-C) applied to phase 2 data allowed predefining phase 3 responder definitions. To confirm in phase 3, median change from baseline at week 12 in average daily number of micturitions, urgency episodes, and UUI episodes was generated for each PGI-C category and pooled across treatments. Based on predefined meaningful responder definitions, percentages of patients achieving ≥ 15% reduction in micturitions (post hoc), ≥ 50% reduction in urgency episodes (predefined), and ≥ 75% (predefined) and ≥ 90% (post hoc) reduction in UUI episodes were determined for patients receiving vibegron or placebo.
Results: Across treatments, for micturitions, urgency episodes, and UUI episodes, median change from baseline to week 12 increased with greater subjective improvement based on PGI-C scores, and median reductions pooled across treatment groups were higher than the responder definitions that patients perceived as improved. Significantly more patients receiving vibegron vs placebo achieved ≥ 15% reduction in micturitions (56.3% vs 44.6%, respectively), ≥ 50% reduction in urgency episodes (39.5% vs 32.8%), ≥ 75% reduction in UUI episodes (49.3% vs 32.8%), and ≥ 90% reduction in UUI episodes (35.2% vs 23.5%) at week 12 (P < 0.05 each).
Conclusion: Significantly more patients treated with vibegron vs placebo in EMPOWUR achieved meaningful reductions in micturitions, urgency episodes, and UUI episodes that were associated with patient-perceived improvement. Results of these analyses support the meaningfulness of reductions in clinical endpoints observed in the 12-week EMPOWUR trial.
Clinical Trials Registration: ClinicalTrials.gov identifier, NCT03492281.
(© 2021. The Author(s).)