In children, Overactive bladder (OAB) is a characteristic lower urinary tract symptom, causing urge incontinence and reducing the quality of life. However, the experience with vibegron in pediatric patients with daytime urinary incontinence (DUI) has not previously been reported, so the effectiveness of this agent remains unclear. The purpose of this retrospective study was to investigate the effectiveness of vibegron for pediatric DUI cases, including refractory cases.

Of the patients treated with vibegron for DUI at our department from March 2019 to April 2022, 57 patients were included, excluding neurogenic bladder cases such as spina bifida and those in whom the efficacy of treatment could not be determined. The efficacy of treatment after vibegron administration and the effect of patient background were examined. Following the criteria of the International Children's Continence Society (ICCS), treatment response was judged as complete response (CR) when DUI disappeared, and partial response (PR) when the frequency of DUI improved by improvement in frequency by 50% or more during vibegron administration. To investigate risk factors of refractory to vibegron, the following factors were evaluated: age at prescription initiation, frequency of DUI, duration of vibegron treatment, presence of Neurodevelopmental disorder (NDD), presence of nocrturnal enuresis, presence of constipation, and use of anti-cholinergic agents before and after vibegron administration. The treatment outcome was analyzed using the Kaplan-Meier method, and a log rank test was used for differences by background.

There were 38 boys and 19 girls, median age at prescription initiation was 111 months (64-202), median prescription duration was 6 months (1-33), and NDD was observed in 24 cases. The starting dose was 25 mg (0.5 tablets) in 24 cases and 50 mg in 33 cases. Vibegron was used as first choice without anticholinergics in 14 cases, changed from anticholinergics in 35 cases, and added-on to anticholinergics in 8 cases. Within the administration term, vibegron was judged as effective (CR+PR) in 40 cases. With treatment for 6 months, the response rate (CR+PR) was 68.3%, with 32.4% of CR (Figure 1). There was no significant difference in response rate between patients with prior anticholinergic use and those with first choice; 24 cases with NDD showed a 72.0% response rate at 6 months, and no significant difference in treatment response was evident compared to those without NDD. The response rate at 6 months was 85.0% for First-choice cases, 66.3% for Switch cases, and 40.7% for Add-on cases, The response rate at 6 months was 59.9% in 42 case refractory to anti-cholinergic agents, including Switch and Add-on cases. Regarding the efficacy of vibegron, no significant differences in background were found in univariate analysis (Table 1).

Vibegron was as effective for treating DUI in children as in adults. Our results confirm that vibegron may play an important role in the treatment of pediatric DUI cases in the future. Vibegron as the first-choice pharmacotherapy in pediatric cases with DUI, as well as in cases refractory to anti-cholinergics, showed early and high therapeutic efficacy. Vibegron administration for DUI was also found to be effective in cases with NDD, which has been reported as a risk factor for refractory DUI with generally poor treatment outcomes.

Short-term response was observed in many of the effective cases. The results of this study suggest that the treatment of daytime urinary incontinence in children may play a significant role in the treatment of daytime urinary incontinence in the future.