Duration of Clinical Efficacy of OnabotulinumtoxinA in Crow's Feet Lines: Results from Two Multicenter, Randomized, Controlled Trials.

Background: Duration of esthetic treatments may contribute to subject satisfaction.

Objective: Describe response duration with onabotulinumtoxinA in crow's feet lines (CFL) and the association of duration with perception of improvement.

Methods: Subjects from 2 double-blind, placebo-controlled trials received onabotulinumtoxinA 24 U in CFL; Study 2 subjects could also receive 20 U in glabella. At Day 30, responders achieved ≥1-grade improvement in Facial Wrinkle Scale (FWS) scores. Median duration of effect for responders and for responders stratified by Subject's Global Assessment of Change in CFL (SGA-CFL) was determined.

Results: Of 1,362 subjects, 833 received onabotulinumtoxinA. In Study 2, 305 subjects also received 20 U in glabella. In Study 1 (150-day follow-up), per investigator and subject assessments, respectively, median response duration was 125 and 144 days for dynamic lines and 137 and 148 days for static lines. Median response duration for dynamic and static lines in Study 2 (120-day follow-up) was 119 to 121 days per investigator and subject assessments. Subjects reporting greater improvement on the SGA-CFL tended to have a longer duration of response on investigator FWS scores at maximum smile.

Conclusion: Response duration with onabotulinumtoxinA in CFL was ≥4 months. Subject perception of CFL improvement may be associated with response duration.