SAN DIEGO, California — Collagenase Clostridium histolyticum (CCH) can significantly reduce the symptoms of Peyronie’s disease, according to results from 2 phase 3 clinical trials.
“From both a physiologic and psychological standpoint, CCH has benefits over placebo,” said researcher Wayne Hellstrom, MD, chief of andrology at Tulane University in New Orleans, Louisiana.
Dr. Hellstrom and his team conducted a post hoc meta-analysis of data from the 2 studies. He presented the results to reporters attending a news conference here at the American Urological Association 2013 Annual Scientific Meeting.
In Peyronie’s disease, scar tissue causes curvature of the erect penis. It can cause pain, sexual dysfunction, and psychological distress. Over time, the scar tissue can calcify.
Peyronie’s affects about 5% of men, many of whom are afraid to discuss it, said Dr. Hellstrom. “Men are losing their penis size and they feel like they’re losing their penis,” he said. “It’s very distressing.”
The condition resolves spontaneously in 10% to 12% of patients, which has made some unproven treatments appear effective, he said.
Currently, surgery is the gold standard, but success varies, depending on the degree of curvature, and not all patients are good candidates for the procedure, he told Medscape Medical News.
Auxilium Pharmaceuticals has applied to the US Food and Drug Administration (FDA) for approval to market collagenase C histolyticum, under the trade name Xiaflex. The FDA, which has never before approved a drug for Peyronie’s disease, will likely reach a decision in September, said Dr. Hellstrom.
The drug is already approved for use in Dupuytren’s contracture, a related syndrome in which scar tissue in the hand prevents fingers from straightening.
Collagenase C histolyticum works by dissolving scar tissue without damaging healthy tissue, Dr. Hellstrom explained.
A clinician injects collagenase C histolyticum directly into the scar tissue using a technique that requires training. Patients are then taught to bend their penises in the direction opposite the curvature. A cycle of treatment involves 2 injections 24 to 72 hours apart, followed by bending.
In the 2 studies, researchers stratified patients by penile curvature and randomized the men to receive treatment or placebo.
The researchers chemically induced erections in the patients then measured the curvature of their penises.
The patients also filled out the Peyronie’s Disease Questionnaire so the researchers could determine how bothered they were by various aspects of their condition. Scores range from 0 (not at all bothered) to 16 (extremely bothered by all aspects).
Twenty-four weeks after treatment, half the men who received the collagenase C histolyticum had straighter penises and were less bothered by the condition, compared with only about a quarter of those who received placebo.
At 52 weeks, there were significantly more composite responders in the collagenase C histolyticum group than in the placebo group (P < .0001).
A few patients experienced inflammation and bruising as a result of the treatment. The only serious adverse events were corporal ruptures, which likely resulted when these men had “vigorous” intercourse too soon after the treatment, Dr. Hellstrom said.
News of the study got varied reactions at the meeting. “I think it’s an important development, in that it gives an alternative to surgery,” Tobias Köhler, MD, told Medscape Medical News.
“There has been no good treatment and that’s why it’s such a big deal,” said Dr. Köhler, who is assistant professor of urology and andrology at the Southern Illinois University School of Medicine in Springfield.
However, the treatment is likely to be expensive, he noted.
A vial of collagenase C histolyticum for Dupuytren’s contracture sells for about $3330, according to a spokesperson for Auxilium Pharmaceuticals. In these trials, 90% of patients received at least 6 vials over the course of treatment.
However, less of the drug might be needed, the spokesperson said. In the trials for Dupuytren’s contracture, 1.7 vials were used, but in the real world, only 1.1 are being used by the typical patient.
Stan Hardin, president of the Association of Peyronie’s Disease Advocates, said he has mixed emotions about the trial. “I think it’s a great result,” he told Medscape Medical News. “But men with calcification are not candidates. I’ve had this for 11 years and I don’t believe I’m a candidate, so personally, there’s a slight disappointment that I can’t benefit from it.”
At the meeting, a separate presentation of results from the same 2 trials drew some comments. “I never in my life thought that Peyronie’s disease would be managed with a double-blind, placebo-controlled drug,” said session moderator Irwin Goldstein, MD, president of the Institute for Sexual Medicine in San Diego, California.
One man in the audience noted the large standard deviation in the results. Statistically, this suggests a wide range of responses to the drug, even if the improvement was statistically significant for the mean patient.
Another argued that he could achieve more straightening with surgery than was achieved with the drug.