FDA Approves Peyronie's Disease Drug

Urologists for the first time have an FDA-approved drug to offer their patients with Peyronie's disease.

The drug, collagenase clostridium histolyticum (Xiaflex), already had been approved as a treatment for Dupuytren's contracture. It is an enzyme produced byClostridium histolyticum that acts like a “chemical knife” to break up collagen.

For Peyronie's disease, the drug is administered through injections into the area where collagen scar tissue, known as Peyronie's plaque, has formed. Following injections, the treated area is massaged or “modeled” to break down the scar tissue. To date, off label use of intralesional verapamil and surgery have been the standard treatment for Peyronie's disease.

Based on U.S. historical medical claims data, it is estimated that 65,000 to 120,000 PD cases are diagnosed annually but only 5,000 to 6,500 patients are treated each year, the drug's maker, Auxillium, said in a press release.

The FDA based its approval on the results of the pivotal IMPRESS I and IMPRESS II trials, in which Xiaflex was compared with placebo.

Xiaflex is indicated for the treatment of Peyronie's disease in men with a palpable plaque and a curvature of 30 degrees or more at the start of treatment. The dose of Xiaflex is 0.58 mg per injection administered into a Peyronie's plaque. Up to eight injections (four treatment cycles) may be administered in the course of treatment. After each treatment cycle, a penile modeling procedure is recommended to disrupt the plaque. If more than one plaque is present, it should be injected only into the plaque causing the curvature deformity.

Possible adverse effects of Xiaflex treatment include hematoma, swelling at the injection site or along the penis, pain or tenderness at the injection site, along and above the penis, and penis bruising.

Stanton Honig, MD, of Yale University in New Haven, Conn., a urologist who specializes in male sexual medicine and was involved in phase 2 and 3 trials of Xiaflex, said physicians, especially those specializing in men's health, “are very excited to be able to offer an FDA approved, nonsurgical treatment option to men who suffer from Peyronie's disease. We know a significant percent of these patients suffer from depressive symptoms as a result of the sequelae of Peyronie's disease, which include shortening of the penis, dysmorphic changes in the penis, and curvature.”

In the clinical studies, Xiaflex treatment was associated with a low rate of major complications, but a significant number of men had local complications, including bruising, swelling, ecchymosis, and hematoma, Dr. Honig said. A few cases of penile fracture occurred, and these were likely related to early sexual activity after treatment.

Surgery is associated with greater improvements in curvature than Xiaflex injections, but surgery poses a greater risk of significant complications, including a shorter penis, erectile dysfunction, and changes in penile sensation, Dr. Honig said.

The ideal candidate for Xiaflex treatment would be a man who has had Peyronie's disease for at least 12 months, has stable disease, and a curvature of 30 degrees or more, he said.

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