Noninferiority of IncobotulinumtoxinA, Free from Complexing Proteins, Compared with Another Botulinum Toxin Type A in the Treatment of Glabellar Frown Lines

BACKGROUND Use of botulinum toxin for esthetic purposes has rapidly expanded over the last 20 years. IncobotulinumtoxinA, also known as NT 201, is a new botulinum toxin type A (150 kDa) that is free from complexing proteins. OBJECTIVES A prospective, multicenter, randomized, rater- and patient-blind, international Phase III trial to investigate the noninferiority of incobotulinumtoxinA to another botulinum toxin type A, onabotulinumtoxinA, in the treatment of glabellar frown lines. METHODS A total of 381 patients were randomized in a 3:1 (incobotulinumtoxinA:onabotulinumtoxinA) ratio to receive 24 U incobotulinumtoxinA of or onabotulinumtoxinA. Efficacy end points included the percentage of responders (patients with an improvement of ≥1 point on a 4-point facial wrinkle scale) at maximum frown at weeks 4 and 12 as assessed by the investigators, and a panel of independent raters based on standardized digital photographs. RESULTS Four weeks after injection, response rates at maximum frown were 96.4% in the incobotulinumtoxinA group and 95.7% in the onabotulinumtoxinA group as assessed by independent raters. Analysis of the data confirmed the noninferiority of incobotulinumtoxinA. Response rates at rest were lower for both products. The rate of adverse events was low. CONCLUSION IncobotulinumtoxinA is equally as effective as onabotulinumtoxinA in the treatment of glabellar frown lines. Both preparations were well tolerated. This study was funded by Merz Pharmaceuticals GmbH. Editorial assistance was provided by Ogilvy 4D, Oxford, UK.