Safety and efficacy of onabotulinumtoxina for treatment of crow's feet lines in Chinese subjects

Background: This study evaluated the safety and efficacy of onabotulinumtoxinA for the treatment of crow's feet lines (CFL) in Chinese subjects. Methods: This 5-month, double-blind, randomized, parallel-group, placebo-controlled phase 3 study was conducted in China. Subjects with moderate-to-severe CFL at maximum smile received a single treatment of onabotulinumtoxinA 24 U (total; n = 316) or placebo (n = 101) on day 1. The primary efficacy measure was the proportion of investigator-assessed responders (achieved CFL severity of none or mild at maximum smile using the Facial Wrinkle Scale with Asian Photonumeric Guide at day 30). Additional endpoints included other response definitions (achieving at least 1-grade improvement at maximum smile and at rest using the Facial Wrinkle Scale with Asian Photonumeric Guide at day 30), 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 group (63.9%) versus the placebo group (5.0%). The proportion of subjects assessing the change in CFL appearance as much improved/very much improved was also significantly greater with onabotulinumtoxinA than placebo (P < 0.001). Subjects' self-assessed outcomes were similar to investigator-assessed results. Median duration of effect with onabotulinumtoxinA was ≥5 months using all responder definitions. A low occurrence of treatment-related adverse events was reported, with no new safety findings. Conclusions: OnabotulinumtoxinA 24 U was effective and well tolerated for the treatment of CFL in Chinese subjects, with responses maintained over 5 months.