Urodynamic evaluation of the efficacy of vibegron, a new β3-adrenergic receptor agonist, on lower urinary tract function in children and adolescents with overactive bladder.

Introduction: Idiopathic overactive bladder (OAB) is defined as an urgency symptom with or without urge incontinence, which is not due to known neurological abnormalities. Since children present with variable symptoms, pediatric nonneurogenic idiopathic OAB is a condition that is difficult to diagnose and treat. Although there are few reports on bladder function in pediatric patients compared to adult patients, it can be useful for diagnosis. Antimuscarinic therapy is the pharmacological mainstay of OAB management. However, antimuscarinic use is limited by side effects and Insufficient effects. Vibegron, a new drug with a different mechanism of action (β3-adrenoreceptor agonist), was recently introduced for treating OAB in adults but has not been studied in the pediatric population.

Objective: This study aimed to determine the efficacy and tolerability of vibegron in children and adolescents with idiopathic OAB.

Study Design: We conducted a retrospective study enrolling pediatric patients with OAB whose symptoms did not improve with behavioral therapy or pharmaceutical therapy. Efficacy and tolerability were assessed via a question, and patients underwent video-urodynamic testing before and during treatment with once-daily 50 mg vibegron. Statistical differences were evaluated using Wilcoxon matched-pairs signed-rank tests.

Results: Out of the 17 patients that were recruited, full study with two urodynamic studies were confirmed by 11 patients. OAB symptoms improved in 14 (82.4%) patients, and 3 patients discontinued treatment because of ineffectiveness. No patients discontinued treatment because of intolerance to vibegron. The median (IQR) first desire to void (133 [82-185]-161 [123-227] mL), bladder capacity (158 [136-238]-204 [150-257] mL), and bladder compliance (18.1 [9.1-76.7]-34.0 [30.0-82.3] mL/cm HO) improved significantly post treatment compared to before treatment. Detrusor overactivity disappeared in one of the eight patients with this condition. The parameters of voiding function did not change significantly after the administration of vibegron.

Discussion: Treatment with vibegron significantly improved clinical and urodynamic parameters of pediatric OAB with no adverse effects. Little information is available regarding the feasibility of switching drugs when patients discontinue prior pharmacological therapy because of insufficient efficacy or poor tolerability in children. Vibegron may be a promising OAB treatment option with a better balance of efficacy and tolerability.

Conclusions: Vibegron is an alternative agent for pediatric patients with idiopathic OAB for improving both subjective symptoms and lower urinary tract function. Future prospective randomized studies with larger sample sizes must be conducted to validate the results of the present study.