The approval of onabotulinumtoxinA has been expanded to include the cosmetic treatment of the lateral canthal lines known as crow’s feet, the Food and Drug Administration announced on Sept. 11.
The product has been approved for "the temporary improvement in the appearance of moderate to severe lateral canthal lines" in adults, the FDA said in a statement. The product, marketed as Botox Cosmetic, is an acetylcholine release inhibitor and a neuromuscular blocking agent, and it was approved in 2002 for the temporary improvement of glabellar lines.
The new indication "will provide people with a new FDA-approved treatment option for those seeking a smoother appearance by temporarily minimizing the appearance of crow’s feet at the sides of the eyes," Dr. Susan Walker, director of the Division of Dermatology and Dental Products in the FDA’s Center for Drug Evaluation and Research, said in the statement. Treatment for the glabellar lines (between the eyebrows) and the canthal lines can be administered at the same time, she said.
Approval was based on two studies of 833 adults with moderate to severe lateral canthal lines, randomized to treatment or placebo. Those treated with onabotulinumtoxinA had "greater improvement compared to placebo in the appearance of lateral canthal lines," the FDA statement said. Eyelid edema was the most common adverse reaction associated with the treatment.
The product has been used off label for canthal lines.
OnabotulinumtoxinA is also marketed as Botox, and is approved for the treatment of chronic migraine, severe axillary hyperhidrosis, blepharospasm associated with dystonia, strabismus, and several other indications. The label includes a boxed warning about the possibility that all botulinum toxin products may spread from the site of injection to other parts of the body, causing botulism-like symptoms. The warning states that such symptoms have been reported hours to week after the injection, and have included life-threatening cases of swallowing and breathing difficulties, and reports of deaths. The warning also states that the risk is "probably greatest in children treated for spasticity, but symptoms can also occur in adults, particularly in those patients who have an underlying condition that would predispose them to these symptoms."
However, "there has not been a confirmed serious case of toxin spread when Botox or Botox Cosmetic has been used at the recommended dose for the approved indications," according to the FDA’s statement announcing the approval.
Botox and Botox Cosmetic are marketed by Allergan Inc.
Adverse events associated with onabotulinumtoxinA should be reported to the FDA at 800-332-1088 or at MedWatch.