The FDA's approval of the Xiaflex which is produced by Auxilium Pharmaceuticals Inc follows the September recommendation of a panel of outside medical experts. The panel unanimously voted to support Xiaflex.
Dupuytren's contracture is an abnormal thickening of tough tissue (fibrous layer) underneath the skin of the palm and fingers. It is the thickening of this tissue that can cause the fingers to curl. When severe, Dupuytren’s can be disabling. Until now there has been no treatment other than surgery. Xiaflex is an injection which will be done in the office. (photo credit)
The cause of Dupuytren’s disease is unknown but is more common in men over age 40 and in people of northern European descent. It is estimated that 7 million to 14 million Americans have Dupuytren's disease.
Xiaflex is a biologic drug made from the protein product of a living organism. It works by breaking down the excessive buildup of collagen when injected directly into the collagen cord of the hand. It should be administered only by a health care professional experienced with injections of the hand.
A study published in the New England Journal of Medicine looked at 308 patients with joint contractures of 20 degrees or more in a prospective, randomized, double-blind, placebo-controlled, multicenter trial showed significant improvement. More cords that were injected with collagenase than cords injected with placebo met the primary end point (64.0% vs. 6.8%). Overall, the range of motion in the joints was significantly improved after injection with collagenase as compared with placebo (from 43.9 to 80.7 degrees vs. from 45.3 to 49.5 degrees).
The most commonly reported adverse events were localized swelling, pain, bruising, pruritus, and transient regional lymph-node enlargement and tenderness. Three treatment-related serious adverse events were reported: two tendon ruptures and one case of complex regional pain syndrome.
Auxilium intends to market the drug for use not only by hand, orthopedic and other surgeons but also to rheumatologists, non-surgeons who specialize in arthritis and other joint issues. Physicians would be trained with a video and a training manual, Auxilium said.
Injectable collagenase clostridium histolyticum for Dupuytren's contracture. ; N Engl J Med 361:968 (2009); Lawrence C Hurst et al.