Efficacy and Safety of Onabotulinumtoxina for the Treatment of Crow's Feet Lines

Friday, April 12, 2013
Alastair Carruthers, MD1, Suzanne Bruce, M.D.2, Sue Ellen Cox, MD3, Simon Connolly, MB, ChB, MRCGP, MBCAM, DPD4, Arlette De Coninck, MD5, Christine Somogyi6, Xiaofang Lei, PhD7, Elisabeth Lee, MPH7, Helen McLean8 and Frederick Beddingfield, MD, PhD7, (1)Division of Dermatology, University of British Columbia, Vancouver, BC, Canada, (2)Dermatology, Suzanne Bruce and Associates, P.A., Houston, TX, (3)Dermatology, University of North Carolina, Chapel Hill, NC, (4)The Private Clinic, Glasgow, United Kingdom, (5)Department of Dermatology, Vrije Universiteit Brussel, Brussels, Belgium, (6)Allergan, Irvine, CA, (7)Allergan Inc, Irvine, CA, (8)Allergan, Ltd, Marlow, United Kingdom
Goals/Purpose:

The objective was to evaluate efficacy and safety of onabotulinumtoxinA in subjects with lateral canthal rhytids (crow’s feet lines [CFL]).

Methods/Technique:

This multicenter, double-blind, placebo-controlled, parallel-group, single-treatment study randomized subjects with moderate-to-severe CFL at maximum smile to onabotulinumtoxinA (24 U; 3 injections/side; 4 U/injection site) or placebo (1:1 ratio). Post-treatment visits were at weeks 1 and 2 and days 30, 60, 90, 120, and 150. Investigators and subjects assessed CFL severity at maximum smile using the Facial Wrinkle Scale with Photonumeric Guide (FWS; 0=none, 1=mild, 2=moderate, 3=severe). Co-primary endpoints were investigator- and subject-assessed proportion of subjects achieving a FWS score of 0 or 1 at day 30. Additional efficacy endpoints included proportion of subjects achieving a ≥1-grade FWS improvement, ≥2-grade improvement, and ≥2-grade composite FWS improvement (investigator- and subject-assessed on a per-subject basis), and patient-reported outcomes. Adverse events (AEs) were monitored.

Results/Complications:

Of 445 subjects enrolled, 222 were randomized to receive onabotulinumtoxinA and 223 placebo. Overall mean age was 46.4 years (range, 22-75 years). All primary and secondary endpoints were achieved (statistically significant differences favored onabotulinumtoxinA; P<.001, all comparisons). Proportion of responders achieving 0 or 1 (day 30) was 66.7% and 58.1% for investigator and subject, respectively. Proportion of subjects achieving at least 1-grade improvement in CFL severity at maximum smile and at rest was significant, favoring onabotulinumtoxinA vs placebo at all time points (P<.001). Composite ≥2-grade improvement was 25.7% vs placebo 1.3% (P<.001). Treatment effects were detected by 1 week post-treatment and lasted up to 5 months. OnabotulinumtoxinA was well tolerated with no statistically significant between-group differences in the incidence of AEs. The majority of AEs were mild or moderate, and no subjects discontinued due to an AE.

Conclusion:

Based on a range of prespecified endpoints, treatment with onabotulinumtoxinA (24 U; 12 U/side) was effective and safe for the treatment of moderate-to-severe CFL as assessed by investigators and subjects. Improvements in CFL were detected by 1 week post-treatment and lasted up to 5 months. Efficacy and safety profiles were consistent with previous aesthetic studies of onabotulinumtoxinA.