Comparison of two botulinum toxin type A preparations for treating crow's feet: a split-face, double-blind, proof-of-concept study.
BACKGROUND
This is the first double-blind, randomized, proof-of-concept study to compare the clinical effectiveness of botulinum toxin type A (BoNTA) free of complexing proteins with a BoNTA complex (BTXCo) in the treatment of crow's feet.


METHODS
Twelve U of each product were compared in an intra-individual study in 21 participants with a facial wrinkle scale (FWS) score of 2 to 3. Evaluations were done for up to 4 months. Subjects with an improvement of at least 1 point on the FWS were considered responders.


RESULTS
One month after treatment, the percentage of responders was slightly higher for the BoNTA side (95%) than the BTXCo side (90%). After 4 months, both sides still showed good efficacy, with an 84% response rate and greater than 30% FWS reduction (no statistically significant difference between the products). After 1 month, FWS score at rest was approximately 66% lower for BoNTA, versus 63% lower for BTXCo. After 4 months, FWS reduction was approximately 50%.


CONCLUSIONS
Both botulinum toxin A products displayed high efficacy and good tolerability at a dose ratio of 1:1, with no statistically significant differences between them. The high response rates observed after 4 months suggest a good effectiveness beyond this observation period.
Dermatologikum Hamburg, Hamburg, Germany. prager@dermatologikum.de
Welf
W
Prager
Esther
E
Wissmüller
Bianca
B
Kollhorst
Stefanie
S
Williams
Ina
I
Zschocke
D000328:Adult; D019274:Botulinum Toxins, Type A / Q000008:administration & dosage*; D004311:Double-Blind Method; D005123:Eye; D005260:Female; D006801:Humans; D007267:Injections; D008297:Male; D008875:Middle Aged; D009465:Neuromuscular Agents / Q000008:administration & dosage*; D015595:Skin Aging / Q000187:drug effects*; D016896:Treatment Outcome
D009465:Neuromuscular Agents; D019274:Botulinum Toxins, Type A