Medicis Pharmaceutical Corp’s newer anti-wrinkle drug Dysport proved significantly better than Botox at improving crow’s feet in a small clinical study, a finding that could give frown lines to market leader Allergan Inc.
Allergan’s Botox (onabutulinumtoxin A) was approved by U.S. regulators in 2002 to treat wrinkles between the eyebrows, while Dysport (abobutulinumtoxin A) won approval for the same indication in 2009. The drugs are similar forms of botulinum toxin, a chemical that can block nerve impulses.
Neither drug is specifically approved to treat crow’s feet, the lines that radiate from the corners of the eye and are most obvious when you squint or smile. But both of the injectable drugs are commonly used by doctors to make the branching wrinkles less apparent.
Results of the 90-patient trial — conducted by Kartik Nettar of the Maas Clinic, San Francisco, and by the University of California, San Francisco — were described on Monday in the online edition of the Archives of Facial Plastic Surgery.
All participants received injections of one drug in the target area on the right side of the face and the other treatment on the left side, to assess potential benefit.
Researchers then assessed the site’s appearance using a five-point scale and patients were also asked their own opinions.
The difference in crow’s feet was deemed by researchers to be significantly favorable to Dysport, when subjects contracted the muscles as much as possible. Moreover, about two thirds of participants said they favored the side of their faces that was treated with Dysport, according to the study.
But the results were deemed limited in scope since no statistical difference between the two treatments was seen when the muscles were at rest.
More studies are needed to assess why one agent would perform better than the other and to compare the affect of the two drugs on other facial muscles, the researchers said.
Crow’s feet are among the first wrinkles to form and can surface in the 30’s. Sun exposure, squinting and smoking are among the biggest causes.
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