Solifenacin in Children and Adolescents with Overactive Bladder: Results of a Phase 3 Randomised Clinical Trial

Background: Solifenacin, an effective, well-tolerated treatment for adult overactive bladder (OAB) symptoms, has not been evaluated in placebo-controlled paediatric clinical trials.

Objectives: To evaluate the efficacy and safety of once-daily oral solifenacin suspension in OAB patients aged 5-<12 yr (children) and 12-<18 yr (adolescents).

Design, setting, and participants: The study involved a 4-wk urotherapy run-in followed by 1:1 randomisation to 12-wk double-blind solifenacin or placebo treatment alongside urotherapy.

Intervention: Solifenacin paediatric equivalent doses (PEDs) of adult doses: 2.5mg, 5mg, 7.5mg, and 10mg. The starting dose was PED 5mg; all patients were titrated to an optimum dose at 3-wk intervals over 9 wk, resulting in ≥3 wk at the optimum dose before end of treatment (EoT).

Outcome measurements and statistics: Superiority of solifenacin versus placebo in change from baseline to EoT for mean volume voided/micturition (MVV, primary endpoint); daytime maximum volume voided/micturition (DMaxVV); incontinence episodes (mean/24h); mean number of incontinence-free days or nights/7 d; micturition frequency; and Micturition frequency adjusted for baseline total voided volume (VT_B) as an exploratory parameter). Efficacy parameters were analysed using analysis of covariance. Safety parameters (treatment-emergent adverse events, serious adverse events, laboratory variables, vital signs, electrocardiogram, postvoid residual volume) are summarised using descriptive statistics.

Results and limitations: In children, solifenacin was superior to placebo in terms of the change from baseline to EoT for MVV (solifenacin-placebo difference 12.1ml, 95% confidence interval [CI] 0.2-24.0; p=0.046), DMaxVV (difference in adjusted mean change from baseline for solifenacin-placebo 31.9ml, 95% CI 4.3-59.5; p=0.024), VT_B-adjusted micturition frequency (p=0.028). Other endpoints were not significantly different. Solifenacin was well tolerated. For adolescents, it was not possible to draw firm efficacy conclusions because of the low numbers recruited.

Conclusions: Once-daily solifenacin oral suspension in children with OAB was superior to placebo for MVV (primary efficacy endpoint) and was well tolerated.

Patient summary: In this 12-wk study, a once-daily oral suspension of solifenacin in children aged 5-<12 yr with overactive bladder was superior to placebo in increasing mean volume voided/micturition, the primary efficacy variable in the study. Solifenacin was well tolerated, with a low incidence of dry mouth and constipation. This study is registered at ClinicalTrials.gov as NCT01565707.