Onset, longevity, and patient satisfaction with incobotulinumtoxinA for the treatment of glabellar frown lines: a single-arm, prospective clinical study

Background: IncobotulinumtoxinA (Bocouture (R)) is free from complexing proteins and effective for treating glabellar frown lines. Purpose: To determine the efficacy, onset, and duration of action of incobotulinumtoxinA for the treatment of glabellar frown lines. Patients and methods: In this single-arm, prospective, proof-of-concept study, 23 patients were treated with 25 U incobotulinumtoxinA, equally split between five injection sites in the glabella. Severity of glabellar frown lines was rated by an independent rater from standardized photographs using the validated Merz 5-point scale at several visits over 5 months following treatment. To assess patient satisfaction, patients completed a questionnaire before and 2 weeks after treatment. Results: The percentage of responders at maximum frown 2-4 days after treatment was 95.2% and 85.0% when responders were defined as patients with >= 1-point and >= 2-point improvement on the 5-point scale compared with baseline, respectively. At this time point, 84% of the maximum effect had occurred. The responder rate at maximum frown, according to both definitions, was 100% for at least the next two visits (days 8 +/- 1 and 14 +/- 2). At all visits, the change from baseline in the mean glabellar frown-line score at maximum frown was statistically significant, with on average an almost 1-point improvement from baseline 5 months after treatment. Conclusion: IncobotulinumtoxinA is an effective and well-tolerated treatment for glabellar frown lines, with a rapid onset of action and a long duration of effect lasting for more than 5 months.