Comparing the Clinical Attributes of AbobotulinumtoxinA and OnabotulinumtoxinA Utilizing a Novel Contralateral Frontalis Model and the Frontalis Activity Measurement Standard

October 2011 | Volume 10 | Issue 10 | Original Article | 1148 | Copyright © October 2011

Mark S. Nestor MD PhDa and Glynis R. Ablon MDb

aCenter for Clinical and Cosmetic Research, Aventura, FL bAblon Skin Institute, Manhattan Beach, CA


Background: Studies on the pharmacodynamics of abobotulinumtoxinA (ABO) and onabotulinumtoxinA (ONA) have produced inconsistent results. This may be due to the lack of objective measurement methods.
Objective: To assess and compare pharmacodynamic attributes, including onset of action, spread and efficacy of ABO and ONA using a novel Frontalis Activity Measurement Standard (FMS) and 4-point Frontalis Rating Scale (FRS).
Methods: Twenty subjects with severe frontalis lines at maximum elevation received equal volumes of ABO or ONA using a dose ratio of 2.5:1 in five injection points on contralateral sides of the frontalis (statistical n=40). Subjects were evaluated using the FMS and FRS for 30 days using pre-defined endpoints for onset and effectiveness. Other assessments included areas of effectiveness and injection pain.
Results: For ABO vs. ONA, the FMS revealed a median Initial Onset of 12 vs. 48 hours (P<0.001), Full Onset of 24 vs. 72 hours (P<0.001) and Complete Onset of three vs. five days (P=0.01). The FRS indicated an Initial Onset for ABO and ONA of 18 hours vs. two days (P=0.002), Full Onset of two vs. three days (P=0.001) and Complete Onset of four days vs. eight days (P=0.01). The FMS showed 90 percent of ABO treatment achieved Complete Efficacy vs. 75 percent for ONO, while 90 percent of ABO treatments reached Complete Efficacy using the FRS vs. 65 percent for ONO. No differences in area of effectiveness or spread were observed. Most subjects (80%) reported ABO injections were less painful than ONA injections (P<0.05).
Conclusion: The FMS appears to be a sensitive, objective tool for measuring ABO and ONA pharmacodynamics. Using a dose ratio of 2.5:1, ABO displayed significantly earlier onset of effect and less injection pain than ONA but similar areas of effectiveness.

J Drugs Dermatol. 2011;10(10):1148-1157.


Several large clinical trials have demonstrated the safety and effectiveness of abobotulinumtoxinA (ABO; Dysport, Medicis Aesthetics, Inc., Scottsdale, AZ, Azzalure® , Galderma Laboratories, Lausanne, Switzerland) and onabotulinumtoxinA (ONA; Botox® Cosmetic, Allergan, Inc., Irvine, CA) for aesthetic purposes.1-5 Both products share the same mechanism of action and each is indicated for temporary improvement in the appearance of moderate-to-severe glabellar lines associated with corrugator and/or procerus muscle activity in adult patients ≤65 years of age;6,7 however, they are manufactured using different proprietary methods and differ with respect to unit potency and the amount of non-toxin protein complexes they contain.8,9 As a result, they have different clinical properties and cannot be used interchangeably.10
Studies attempting to compare the effectiveness and duration of ABO and ONA products have lacked an objective metric for comparing their pharmacodynamic effects on muscle activity.11-17 Comparisons regarding units of activity, onset, effectiveness and durability of effect as well as area of effectiveness (spread) vary significantly.10,12,14,18-24 Additionally, large BoNTA clinical trials typically begin capturing onset and efficacy data one week or more after treatment,1-4 and the onset of BoNTA activity has not been adequately described.
To better assess the clinical activity of BoNTA products, a new Frontalis Activity Measurement Standard (FMS) has been developed. The FMS is a sensitive and objective metric for measuring