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.