Interferon is safe, effective for Peyronie's disease

In the study, three-fourths of men treated with low-dose intralesional interferon alfa-2b reported significant improvement in curvature. The drug is not FDA approved for Peyronie's disease, but it is approved and utilized at significantly higher doses for malignant melanoma and chronic hepatitis. Prior multi-institutional studies have also reported the safety and efficacy of low-dose intralesional interferon alfa-2b for Peyronie's disease.

In this trial, 30 men with Peyronie's disease-including 10 with significant plaque and curvature only and 20 with concomitant mild to moderate ED responding to an oral phosphodiesterase type-5 inhibitor or intracavernosal injection therapy-were treated with a 12-week course of biweekly injections of interferon alfa-2b, 5 million units. Responses were evaluated at week 18 using hemodynamic studies for objective assessment and patient self-reports of treatment satisfaction. Twenty-two men went on to receive a second course of six injections.

Of the seven non-responders, five patients went on to surgery to straighten residual curvature. The prior interferon alfa-2b injections did not complicate the surgery, and if anything, made it easier by reducing the amount of curvature that needed to be fixed, Dr. Hakim explained.

"Peyronie's disease presents a frustrating therapeutic challenge for patients and physicians because of the lack of good non-surgical treatment options," he said. "The available results suggest that intralesional interferon alfa-2b may be considered as a first-line intervention for men with Peyronie's disease."

Thirty-five patients presenting with significant stable penile curvature and plaque were initially evaluated for interferon alfa-2b treatment with a comprehensive screening. Plaque and curvature had been present for 6 months to 5 years, and the degree of curvature ranged from 10 to 85 degrees.

Five of the initial 35 patients with large, typically calcified plaque and severe organic ED that was refractory to conventional ED medical treatment were excluded from interferon alfa-2b treatment.

"The goal in treating these patients is to allow them to achieve a straighter, rigid, more functional erection," Dr. Hakim said. "However, if there is severe, refractory ED, a trial of interferon alfa-2b is less appropriate, because even if it is effective in causing straightening, the patient will still not be able to be sexually active."

Injections were performed after giving a local penile block for anesthesia, and acetaminophen or a non-steroidal anti-inflammatory drug as pre-medication and after the injections. The interferon alfa-2b dose was diluted in 9 cc of normal saline, and the total volume was delivered intralesionally in a series of injections.

At the 18-week visit, eight patients (26.7%) had achieved treatment satisfaction with enough improvement in penile curvature/shape to allow comfortable intercourse for men and their partner with or without a PDE-5 inhibitor. The remaining 22 men proceeded to a second course of interferon alfa-2b, and 15 of those individuals, including two who had been unresponsive to previous treatment with intralesional verapamil, achieved treatment success.

"The experience with these men indicates that interferon alfa-2b should not be ruled out for men who have failed previous medical treatment for their Peyronie's disease," Dr. Hakim said.