Overactive bladder syndrome (OAB) is characterized by bothersome urinary symptoms, including urinary urgency, accompanied by nocturia and frequency, with or without urgency urinary incontinence (UUI). OAB symptoms, particularly UUI, can adversely impact patients’ daily lives, resulting in reduced quality of life (QoL). Vibegron is a β3-adrenergic agonist approved for adults with OAB. In the phase 3, randomized, double-blind, placebo- and active-controlled EMPOWUR trial, once-daily vibegron significantly improved symptoms of OAB vs placebo at week 12 [1]. Vibegron also resulted in significant improvements vs placebo at week 12 in OAB questionnaire (OAB-q) scores and Patient Global Impression (PGI) scores, 2 patient-reported outcomes for assessing QoL [2]. This post hoc analysis evaluated changes in OAB-q and PGI scores relative to UUI episode reduction.

In the EMPOWUR trial, patients with OAB wet or dry were randomly assigned 5:5:4 to receive vibegron 75 mg, placebo, or active control (tolterodine 4 mg extended release), respectively, once daily for 12 weeks. In EMPOWUR, OAB wet was defined as an average of ≥8 micturitions and ≥1 UUI episodes per day at baseline, recorded in a 7-day voiding diary; OAB dry was defined as an average of ≥8 micturitions, ≥3 urgency episodes, and <1 UUI episode per day. Patients recorded UUI episodes in a voiding diary for the 7 days leading up to each trial visit. Patients may have had stress or mixed UI episodes, but only average daily UUI (aUUI) episodes were assessed in this analysis. To assess patient-reported QoL, the OAB-q (1-week recall) was completed at baseline and week 12, and PGI items (Severity, Control, Frequency, Leakage, Change) were completed at baseline and weeks 4, 8, and 12. The OAB-q health-related QoL (HRQL) subscale (including coping, concern, sleep, and social interaction domains) and symptom bother subscale are scored 0–100; increases indicate improvement for HRQL scores, whereas decreases indicate improvement for symptom bother score. PGI subscales are scored 1−4 for severity; 1−5 for control, frequency, and leakage; and 1−7 for change, with decreases indicating improvement. This post hoc analysis assessed change from baseline in OAB-q subscale scores and PGI scores among patients who received vibegron and had OAB wet at baseline (ie, full analysis set for incontinence) using descriptive statistics without imputation for missing data. To assess changes in OAB-q and PGI subscale scores, in this post hoc analysis, patients who received vibegron were categorized as aUUI=0 (dry/UUI continent), 0<aUUI<1 (episodic continence), and aUUI ≥1 (incontinent).

A total of 1127 patients with OAB wet were included in the EMPOWUR trial (vibegron, n=403; placebo, n=405; tolterodine, n=319). Baseline mean daily number of UUI episodes were similar across treatment groups (Table). At week 12, a greater percentage of patients who received vibegron were categorized as aUUI=0 vs placebo (25.8% vs 19.6%). Patients who received vibegron and were categorized as aUUI=0 at week 12 had greater mean (SD) improvements vs those who were 0<aUUI<1 or aUUI ≥1 in OAB-q HRQL (Figure; 22.4 [20.7] vs 19.3 [18.5] and 17.1 [25.4], respectively) and symptom bother (−30.0 [22.1] vs −26.8 [19.5] and −19.8 [25.0]) scores. They also had greater mean (SD) improvements vs those who were 0<aUUI<1 or aUUI ≥1in PGI-Severity (Figure; −1.1 [0.9] vs −0.9 [0.7] and −0.6 [0.8], respectively), PGI-Control (−1.4 [1.1] vs −1.0 [1.0] and −0.8 [0.9]), PGI-Frequency (−1.6 [1.0] vs −1.2 [1.0] and −0.8 [1.0]), PGI-Leakage, (−1.5 [1.0] vs −1.0 [1.0] and −0.7 [1.1]), and PGI-Change (−1.9 [1.2] vs −1.6 [1.3] and −1.1 [1.6]).

In EMPOWUR, treatment with vibegron was associated with improvements in number of mean daily UUI episodes vs placebo, with more patients treated with vibegron reporting no UUI episodes by week 12. For those treated with vibegron, improvements in UUI episodes were associated with improvements in OAB-q and PGI scores regardless of continence status, with patients who achieved 0 UUI episodes or <1 UUI episode reporting the greatest improvements in OAB-q and PGI scores.

More patients treated with vibegron vs placebo achieved dry status by week 12 in EMPOWUR. In this post hoc analysis of patients treated with vibegron, achieving dry status was associated with greater patient-reported QoL improvements.

Staskin D, Frankel J, Varano S, Shortino D, Jankowich R, Mudd PN, Jr. J Urol. 2020;204(2):316-324.
Frankel J, Varano S, Staskin D, Shortino D, Jankowich R, Mudd PN, Jr. Int J Clin Pract. 2021;75(5):e13937.

Continence 7S1 (2023) 100954
DOI: 10.1016/j.cont.2023.100954