Overactive bladder (OAB) is characterized by urinary urgency, often accompanied by frequency and nocturia, with or without urge urinary incontinence, referred to as OAB wet and dry, respectively. In the phase 3 EMPOWUR trial, vibegron—a β3-adrenergic receptor agonist approved for the treatment of adult patients with OAB—was associated with significant improvements in daily number of urgency episodes (the need to urinate immediately; P<0.01) and micturitions vs placebo (P<0.001). These post hoc analyses of EMPOWUR assessed efficacy outcomes in patients with OAB wet and OAB dry.

In the EMPOWUR trial, men and women with OAB were randomly assigned 5:5:4 to receive once-daily vibegron 75 mg, placebo, or active control (tolterodine 4 mg extended release), respectively, for 12 weeks. OAB wet criteria included an average of ≥8 micturitions and ≥1 urge urinary incontinence episode per diary day. Up to 25% of patients could have OAB dry, defined as ≥8 micturitions, ≥3 urgency episodes, and <1 urge urinary incontinence episode per diary day on average. Outcomes assessed included change from baseline in average daily number of urgency episodes and micturitions.

Of the 1463 patients included in the full analysis set (all randomized patients who took ≥1 dose of double-blind study treatment and had ≥1 evaluable change from baseline micturition measurement), 1127 (77%) had OAB wet (vibegron, N=403; placebo, N=405; active control, N=319), and 336 (23%) had OAB dry (vibegron, N=123; placebo, N=115; active control, N=98). Vibegron was associated with significant reductions vs placebo in least squares mean (95% CI) change from baseline at week 12 in urgency episodes for the wet (–3.0 [‒3.3, ‒2.6] vs –2.4 [‒2.7, ‒2.0], respectively; P<0.05) and dry (–2.6 [‒3.2, ‒2.0] vs –1.6 [‒2.2, ‒0.9]; P<0.05) populations; significant reductions were also seen with vibegron vs placebo at weeks 2, 4, and 8 for both the wet and dry populations (P<0.05, each). Vibegron was associated with significant reductions vs placebo in least squares mean (95% CI) change from baseline at week 12 in number of micturitions for the wet (–2.1 [‒2.4, ‒1.9] vs –1.7 [‒1.9, ‒1.5], respectively; P<0.01) and dry (–1.8 [‒2.3, ‒1.3] vs –1.0 [‒1.5, ‒0.5]; P<0.05) populations; significant reductions were also seen with vibegron vs placebo at weeks 2, 4, and 8 in the wet population and at weeks 4 and 8 in the dry population (P <0.05, each).

In this subgroup analysis of the EMPOWUR trial, once-daily vibegron 75 mg was associated with significant reductions vs placebo in daily urgency episodes and number of micturitions in patients with OAB wet and OAB dry, suggesting that vibegron is similarly effective for these endpoints in OAB wet and in OAB dry.

Treatment with vibegron was associated with significant improvements in daily urgency episodes and micturitions in patients with OAB wet and OAB dry. These results suggest that vibegron is similarly effective for these symptoms in patients with and without urinary incontinence.