Intravesical Instillation of OnabotulinumtoxinA in the Treatment of Refractory Overactive Bladder in Participants with Urinary Incontinence.

Purpose: Intradetrusor injections of onabotulinumtoxinA are efficacious for the treatment of overactive bladder with urgency urinary incontinence in adults refractory to or intolerant of anticholinergics. Delivery of onabotulinumtoxinA via instillation would reduce the need for intradetrusor injections. The objective of this trial was to assess the efficacy and safety of intravesical instillation of an onabotulinumtoxinA + hydrogel admixture.

Materials And Methods: After review of a stage 1 safety phase by an independent committee, participants were recruited into stage 2 and randomized to either onabotulinumtoxinA 100, 300, 400, or 500 U, or placebo, all with hydrogel admixture. End points included change from baseline to week 12 in the number of urinary incontinence episodes (primary); micturition, urgency urinary, and nocturia episodes/day; volume voided per micturition; proportion of participants with a ≥50% decrease from baseline in urinary incontinence episodes/day; and Overactive Bladder Questionnaire total score. Adverse events were reported.

Results: Change from baseline to week 12 in number of urinary incontinence episodes was -2.72 with placebo and ranged from -0.89 to -1.85 in the onabotulinumtoxinA + hydrogel treatment groups. No difference from placebo was observed for any efficacy end point. The proportions of participants with treatment-emergent adverse events were similar among all groups, with asymptomatic bacteriuria the highest reported (6.7%-15.5%). There were no reports of urinary retention or elevated post-void residual volume.

Conclusions: Intravesical instillation of an onabotulinumtoxinA + hydrogel admixture for the treatment of refractory overactive bladder was well tolerated, but it showed no improvement over placebo.