Intralesional interferon safe, effective for Peyronie's

October 15, 2005

New Orleans--Oral and topical agents are well established as effective nonsurgical treatments for Peyronie's disease. Judging by the results of a recent multicenter study, intralesional therapy will soon join them on that list.

New Orleans-Oral and topical agents are well established as effective nonsurgical treatments for Peyronie's disease. Judging by the results of a recent multicenter study, intralesional therapy will soon join them on that list.

The prospective, single-blind, placebo-controlled, parallel trial involved 117 men treated with either intralesional saline or intralesional interferon alpha-2b (IFN-α2b) administered biweekly for a total of 12 weeks. The treatment group enjoyed significantly greater improvements in such areas as penile curvature, plaque size, plaque density, and pain resolution than men who received placebo.

"Intralesional IFN-α2b injections for the minimally invasive treatment of Peyronie's disease are safe and effective for patients desiring a nonsurgical alternative," Muammer Kendirci, MD, a fellow in andrology working with Wayne Hellstrom, MD, at the Tulane University Health Sciences Center here.

Patients were evaluated with sexual and medical histories, a physical exam, and laboratory testing. Comorbidities were documented, although no significant differences in the rate of comorbidities were identified between the treatment and placebo groups.

Investigators assessed sexual function using the appropriate domain of the International Index of Erectile Function questionnaire. Plaque size measurements were taken using hand-held calipers, and a protractor was used to measure penile curvature.

Sixty-two patients were assigned to receive placebo treatment, while 55 were placed in the IFN-α2b group. The latter received 5×106 units of IFN-α2b in six biweekly injections over 12 weeks, while placebo patients were given saline, 10 mL, in the same manner.

A total of 53 patients in the control group and 50 patients in the IFN-α2b arm completed the study. Nine placebo-treated men and five IFN group members withdrew from the study because of concomitant health problems, dislike of injections, or dissatisfaction with the treatment.

Significant improvements

"Both groups showed improvement in penile curvature, for instance, but the improvement in the IFN group was significantly better than that of placebo," said Dr. Kendirci. "Pain resolution was 28% in placebo and 68% in IFN-treated patients."

Penile hemodynamic measurements revealed that men who received IFN-α2b injections documented improvement in mean peak systolic cavernosal blood flow velocity, while those in the placebo group did not. IFN-α2b patients also experienced a significantly greater decrease in the number of penile vascular pathologies.

"The improvement in peak systolic velocity may be due to either improvement in penile curvature or reduction in plaque size," noted Dr. Kendirci. "That may not be meaningful in a patient who, for example, has a peak systolic velocity of 35 or 40 [cm/sec]. But if a patient is at 25 and improves by 5, that's enough to shift them from the abnormal group to the normal group."

Side effects-mainly flu-like symptoms-were documented in a number of IFN-treated men, but the investigators reported that these were mild and could be treated effectively with anti-inflammatory agents.