OnabotulinumtoxinA (Botox) in the Treatment of Crow’s Feet Lines in Japanese Subjects

BACKGROUND: This study evaluated the safety and efficacy of onabotulinumtoxinA in Japanese subjects with crow’s feet lines (CFL). METHODS: This phase 3, multicenter, double-blind, randomized study included 2 treatment periods: 6-month placebo-controlled period followed by a 7-month open-label period. In period 1, subjects with moderate to severe CFL received onabotulinumtoxinA 24 U (n = 104) or 12 U (n = 99), or placebo (n = 97). In period 2, placebo subjects switched to onabotulinumtoxinA 24 U or 12 U (double-blind dose). Up to 5 total treatments were permitted for subjects meeting re-treatment criteria. The primary efficacy measure was the proportion of investigator-assessed responders (achieving CFL severity of none or mild at maximum smile using the Facial Wrinkle Scale with Asian Photonumeric Guide [FWS-A] at day 30 of treatment 1). Additional endpoints included other responders (achieving at least 1-grade improvement at maximum smile and at rest using the FWS-A at day 30), responders at other time points, duration of effect, subject-reported outcomes, and safety. RESULTS: All efficacy endpoints were met. At day 30, the proportion of subjects achieving none or mild severity at maximum smile was significantly greater (P < 0.001) in the onabotulinumtoxinA 24 and 12 U groups (68.3 and 56.6%, respectively) compared with the placebo group (8.2%). Efficacy results were consistent over repeated treatments, and subjects’ self-assessed outcomes were similar to investigator-assessed results. CONCLUSIONS: Treatment with onabotulinumtoxinA 24 and 12 U improved the appearance of CFL in Japanese subjects and was well tolerated, with no new safety findings. LEVEL OF EVIDENCE I: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266.