Results of a randomized, double-blind, placebo-controlled study to evaluate the efficacy and safety of a botulinum toxin type A topical gel for the treatment of moderate-to-severe lateral canthal lines

Background: Injections of botulinum toxin type A are commonly used to treat facial wrinkles; however, undesirable effects are associated with injections (e.g., pain, bruising, ptosis, immunogenicity, and needle aversion). To address these issues, RT001 Botulinum Toxin Type A Topical Gel is being developed for the treatment of lateral canthal lines. Objectives: To assess the safety and efficacy of RT001 for the treatment of lateral canthal lines in a randomized, double-blind, placebo-controlled study. Materials & Methods: Adult subjects were enrolled to receive a single treatment of RT001 (n=45) or placebo (n=45) applied topically in the lateral canthal area. The primary endpoint was the composite of the Investigator Global Assessment of Lateral Canthal Line Severity (IGA-LCL) and the Patient Severity Assessment of lateral canthal line severity (PSA) defined as a 2-point or greater improvement on both scales. Results: At four weeks, 44.4 percent of subjects treated with RT001 achieved a 2-point or greater improvement on a rigorous composite of both the IGA-LCL and PSA scales compared to 0.0% for the placebo subjects (P<0.0001). At four weeks, 88.9 percent of subjects achieved clinically relevant improvement by investigator assessment. Adverse events were mild in severity and unrelated to study treatment. Conclusions: RT001 appears to be a safe and well-tolerated treatment for improvement of lateral canthal lines.