Time to onset of response of abobotulinumtoxina in the treatment of glabellar lines: a subset analysis of phase 3 clinical trials of a new botulinum toxin type A.

Background: A new botulinum neurotoxin type A formulation, abobotulinumtoxinA (BoNTA-ABO; Medicis Aesthetics Inc., Scottsdale, AZ), was approved in 2009 in the United States for treatment of moderate to severe glabellar lines in adults younger than 65. OBJECTIVE To determine onset of response based on participant assessments recorded from days 1 through 7.
Materials & Methods: Time to onset was assessed as a secondary endpoint in four multicenter, double-blind, placebo-controlled, randomized phase 3 trials evaluating BoNTA-ABO efficacy. Participants received 50 to 80 U of BoNTA-ABO (n=1,160) or placebo (n=580) at five injection sites in the glabellar region. Participants self-evaluated and recorded first effects.
Results: Response on day 1 was 13.4% to 32.5% in participants receiving BoNTA-ABO and 3% to 7% in those receiving placebo. Integrated analysis of three studies showed that 19.7% of participants responded by day 1; median onset was 3 days for BoNTA-ABO and 15 days for placebo. Men responded less frequently in fixed-treatment studies than in the study in which doses were adjusted for muscle mass.
Conclusions: Treatment with BoNTA-ABO demonstrates significantly greater reduction in glabellar lines than placebo. Improvement was seen as early as 24 hours, with median time to onset of 2 to 4 days.
(© 2011 by the American Society for Dermatologic Surgery, Inc.)