Botulinum neurotoxin type A trials in aesthetic indications have used differing efficacy parameters and responder definitions.
To analyze the treatment efficacy and duration of incobotulinumtoxinA for glabellar frown lines using pooled data from 2 large, Phase 3, placebo-controlled trials, and end points similar to those used in previous botulinum neurotoxin type A studies.
MATERIALS AND METHODS
IncobotulinumtoxinA and placebo groups comprised 366 and 181 subjects, respectively. The efficacy of a single 20-U treatment of incobotulinumtoxinA or placebo was evaluated by investigator-assessed and subject-assessed responder rates (≥1-point improvement from baseline), mean score, and mean change from the baseline glabellar frown line severity score.
At all follow-up visits, responder rates and mean change from the baseline score (investigator-assessed and subject-assessed) were significantly greater for incobotulinumtoxinA versus placebo (p < .0001). The maximum investigator-assessed responder rate (93.1%) was achieved at Day 30 after treatment, when the mean improvement on the 4-point facial wrinkle scale peaked at 1.88. Treatment effect declined over time but the investigator-assessed responder rate was 45.7% at the end of the study.
Superiority of incobotulinumtoxinA over placebo for treating glabellar frown lines was confirmed. IncobotulinumtoxinA achieved a maximum responder rate of 93.1% and a long duration of treatment effect: 45.7% of subjects showed efficacy at 120 days.