title: Duration of action of abobotulinumtoxina and onabotulinumtoxina: a randomized, double-blind study using a contralateral frontalis model.
abstract: OBJECTIVE
  To measure and compare the duration of action of abobotulinumtoxinA and onabotulinumtoxinA.
  
  
  METHODS
  Randomized, double-blind, contralateral (split-face) study.
  
  
  METHODS
  Two United States clinical sites.
  
  
  METHODS
  Twenty subjects with severe frontalis lines at maximum elevation.
  
  
  METHODS
  Subjects randomly received equal volumes of abobotulinumtoxinA or onabotulinumtoxinA (0.2mL) in five injection points on contralateral sides of the frontalis (N=40) using a dose ratio of 2.5:1.0 (total 25U abobotulinumtoxinA:10U onabotulinumtoxinA), respectively. Subjects were evaluated using a 4-point Frontalis Rating Scale and a new objective Frontalis Activity Measurement Standard for 210 days using predefined endpoints for efficacy.
  
  
  RESULTS
  Using the Frontalis Activity Measurement Standard, the median duration of "complete efficacy" was 72 days for abobotulinumtoxinA and 56 days for onabotulinumtoxinA (p=0.01), "full efficacy" was 103 days for abobotulinumtoxinA and 87 days for onabotulinumtoxinA (p<0.003), and "partial efficacy" was 105 days for abobotulinumtoxinA and 99 days for onabotulinumtoxinA (p=0.006). Using the Frontalis Rating Scale, the median duration of "complete efficacy" was 63 days for abobotulinumtoxinA and 44 days for onabotulinumtoxinA (p=0.006), "full efficacy" was 119 days for abobotulinumtoxinA and 77 days for onabotulinumtoxinA (p=0.005), and "partial efficacy" was 160 days for abobotulinumtoxinA and 145 days for onabotulinumtoxinA (p=NS). Adverse events included local bruising and occasional headache, but no significant inter-group differences.
  
  
  CONCLUSIONS
  The contralateral Frontalis Activity Measurement Standard is well-suited for assessing the pharmacodynamic and clinical attributes of botulinum toxin type A and can be used to measure differences in the clinical properties of abobotulinumtoxinA and onabotulinumtoxinA. Using a dose ratio of 2.5:1.0, abobotulinumtoxinA displayed significantly longer duration of action than onabotulinumtoxinA.
authors.affiliation: Center for Clinical and Cosmetic Research, Aventura, Florida, USA. nestormd@admcorp.com
authors.forename: Mark S
authors.initials: MS
authors.lastname: Nestor
authors.forename: Glynis R
authors.initials: GR
authors.lastname: Ablon