Efficacy and safety of oxybutynin topical gel 3% in patients with urgency and/or mixed urinary incontinence: a randomized, double-blind, placebo-controlled study.

Aims: To assess the efficacy and safety of oxybutynin transdermal gel 3% (OTG3%), with propylene glycol for enhanced skin permeation, in patients with urinary incontinence (UI).

Methods: In this phase 3 study, 626 patients ≥18 years old with urgency and/or mixed UI symptoms and predominantly urgency UI for ≥3 months were randomized 1:1:1 to receive 12 weeks of OTG3% 84 mg, OTG3% 56 mg, or placebo gel applied once daily to abdomen, inner/upper thigh, or upper arm/shoulder. Primary efficacy endpoint was change from baseline to Week 12 in weekly UI episodes recorded in 3-day bladder diaries. Results were compared using analysis of covariance. Adverse events (AEs) were monitored.

Results: Efficacy was assessed in 601 (intent-to-treat) and safety in 626 patients. At 12 weeks, OTG3% 84 mg/day achieved significantly greater improvement versus placebo in weekly UI episodes (mean change from baseline: -20.4 vs. -18.1; P < 0.05(a)), daily urinary frequency (-2.6 vs. -1.9; P = 0.001(b)), and urinary void volume (32.7 vs. 9.8; P < 0.0001(b)). Dry mouth, the most common treatment-related AE, occurred more often with OTG3% 84 mg/day (26/214 [12.1%]) vs. placebo (10/202 [5.0%]) (P = 0.028); 4 OTG3% patients withdrew because of dry mouth. Application site erythema occurred more often with OTG3% 84 mg/day (8/214 [3.7%]) versus placebo (2/202 [1.0%]) (P = NS); 12 OTG patients withdrew because of skin irritation. No serious treatment-related AEs occurred.

Conclusions: OTG3% 84 mg/day was well tolerated and effective in improving urge incontinence or mixed UI symptoms with a predominance of UI in adults with overactive bladder.