Background: A new botulinum toxin type A (BoNT-A) has been assessed in the United States for treatment of glabellar lines. In April 2009, the US FDA approved the Biologics License Application for a new US formulation of BoNT-A (Dysport [abobotulinum toxin A]; Medicis Aesthetics Inc., Scottsdale, AZ).
Objective: To compare efficacy and safety of a single treatment of BoNT-A with placebo in subjects with moderate to severe glabellar lines.
Methods and materials: One hundred fifty-eight subjects with moderate to severe glabellar lines were randomized 2:1 to receive 50 U of BoNT-A (n=105) or placebo (n=53). Responders were defined as having no or mild glabellar lines at 30 days posttreatment according to investigator and subject assessments (co-primary endpoint) using the validated Glabellar Line Scale Score at maximum frown. Subject diaries were used to document onset of effect. When conducting the research, the authors conformed to the ethical guidelines of the 1975 Declaration of Helsinki.
Results: According to investigator assessment, the proportion of responders to BoNT-A at Day 30 was 89.5%, versus 7.5% for placebo (p<.001); according to subject assessment, the proportion of responders was 75.7%, versus 9.8% for placebo (p<.001).
Conclusion: A single treatment with BoNT-A (50 U) was significantly superior to placebo in the correction of moderate to severe glabellar lines, with comparable tolerability.