Split-Face Double-blind Study Comparing the Onset of Action of OnabotulinumtoxinA and AbobotulinumtoxinA

Objective: To report and discuss the outcome of a prospective, internally controlled, randomized, double-blind, split-face study comparing the onset of action of 2 commercially available botulinum neuromodulators. Methods: Ninety individuals with moderate-to-severe lateral orbital rhytids were treated with onabotulinumtoxinA, 10 U, and abobotulinumtoxinA, 30 U, for the treatment of lateral orbital rhytids. Participants were assessed live with a validated 5-point photographic scale before treatment and on days 2, 4, and 6 after treatment. Photographs were taken at each encounter. Statistical analysis was applied to evaluate for any significant difference in onset of action between the 2 products. Results: AbobotulinumtoxinA and onabotulinumtoxinA demonstrated statistically significant change from baseline at day 2 in the treatment of lateral orbital rhytids at maximal contraction and rest when evaluated independently by investigator and participant (P < .001). Also at day 2, the improvement with abobotulinumtoxinA was better than that with onabotulinumtoxinA for the primary end point of maximal contraction graded by the investigator, although this did not reach statistical significance (P = .21); by day 4, the greater improvement achieved with abobotulinumtoxinA reached statistical significance (P = .02) and remained superior at day 6 (P = .02). The primary findings were strengthened by similar results in the secondary end points of patient self-grade at maximal contraction and at rest and of investigator grade at rest. Conclusions: In conclusion, both abobotulinumtoxinA and onabotulinumtoxinA achieved statistically significant onset of action at day 2. This improvement was seen in all end points, with abobotulinumtoxinA demonstrating a trend toward greater improvement than onabotulinumtoxinA at day 2 and a statistically significant greater improvement at days 4 and 6 when looking at maximal contraction.