Abstract

Background: Intralesional therapies provide an alternative to surgical treatment of Peyronie’s disease (PD). This study examines the efficacy of intraplaque injections of interferon-α-2B (IFN-α-2B) in the treatment of PD.

Methods: Twenty-five patients were enrolled in the study with 21 completing the study. The average age of the study participants was 55.8 years, with 10 of the 21 having diabetes, hypertension, or both. Seven patients received placebo injections using 10 ml saline biweekly for 6 weeks before interferon therapy, and all 21 patients received biweekly injections of 2 × 10⁶ U IFN-α-2B for 6 weeks before reevaluation. Patients were evaluated with duplex Doppler ultrasonography to assess penile curvature and blood flow.

Results: The International Index of Erectile Function questionnaire was completed by 14 of 21 men to assess severity of erectile dysfunction (ED) before and after treatment. Improvements of 20% or more in penile curvature occurred in 14 (67%) of 21 men. Penile pain decreased in eight (80%) of 10, and plaque size decreased subjectively in 15 (71%) of 21 participants. The International Index of Erectile Function questionnaire showed significant improvement of ED in five (71%) of seven men with baseline moderate to severe ED. Peak systolic blood flow improved in three (43%) of seven men with baseline hemodynamic impairment, and veno-occlusive disease resolved in three (18%) of 17 individuals. IFN-α-2B injections led to significant improvements in penile pain and curvature caused by PD.

Conclusion: Results of intralesional IFN-α-2B injections in improving ED are encouraging. The study findings warrant further investigation of the effectiveness of IFN-α-2B injections for treatment of PD.

Peyronie’s disease (PD), which was named after Louis XIV’s personal physician Francois Gigot de la Peyronie after his publication on this condition, is characterized by an inelastic, fibrous scar involving the tunica albuginea of the corpus cavernosa. This condition affects approximately 3.7% of men aged 40 to 70 years, with numerous reports of younger individuals affected. ¹ A palpable plaque, painful intercourse, and penile curvature are common manifestations of PD. In addition, approximately 30 to 40% of patients complain of significant erectile dysfunction (ED). Altogether, these symptoms can lead to a significant decrease in quality of life and adverse psychological effects in as many as 77% of patients. ²Recent theories propose that PD results from penile trauma and injury to the tunica albuginea during sexual intercourse. The microinjury and bleeding in the tunica albuginea leads to fibrin deposition and cytokine release as the healing process is initiated. In PD, evidence suggests that the tunica albuginea displays a disordered wound-healing process—an imbalance between scar formation and remodeling. As a result, there is prolonged and aberrant healing that leads to plaque formation.

Intralesional injection of Peyronie’s plaques has been a focus of nonsurgical therapy in the treatment of PD for many years. In the 1950s steroid injections were reported to reduce both plaque size and penile pain but were also associated with local tissue atrophy and fibrosis that hindered any further surgery. ³ Controlled studies with intralesional collagenase demonstrated significant benefits in penile curvature in patients with less severe forms of PD.⁴ Recently, intralesional injections of calcium-channel blockers have gained popularity. By blocking calcium, an essential component for the extracellular transport of collagen, uncontrolled studies with verapamil have shown improvement in penile curvature in 60% of PD patients with few adverse effects. ⁵ However, the benefits of this treatment have been limited to patients with minimally calcified plaques and penile deviation of less than 30 degrees. ⁶

Key Points

* Peyronie’s disease is a more prevalent condition than previously recognized, and now more so with the introduction of an effective oral erectogenic agent (ie, sildenafil).

* Intralesional injection of Peyronie’s plaques is a minimally invasive treatment for this condition.

* A dose of 2 × 10⁶ U interferon-α-2B delivered biweekly for 6 weeks is equally as efficacious as the higher doses administered for long durations in improving penile curvature, penile pain, and erectile function in men with Peyronie’s disease.

On the basis of dermatologic in vitro fibroblast studies demonstrating inhibition of fibrosis by interferons, clinical research has focused on intralesional interferons for the treatment of PD. A number of clinical trials have demonstrated significant changes in penile curvature, plaque size, and penile pain. ^7–9 Other studies have questioned the benefits of interferon therapy.^10,11 Differences in technique or therapeutic regimen may have contributed to the different conclusions reached by these studies. The dosage of interferon and its frequency of administration may be an important factor in the efficacy of treatment. This study used a dose of 2 × 10⁶ U of interferon-α-2B (IFN-α-2B) in 10 ml of normal saline twice a week for a 6-week period. The dose of interferon and the dosing regimen of this study differ from that of other studies previously conducted by Tulane University, which used 1 × 10⁶ U of IFN-α-2B biweekly for 6 months and 4 × 10⁶ U of IFN-α-2B once a week for 10 weeks. ^7,9 In this clinical trial, we further report on the safety and efficacy of intralesional interferon therapy, and evaluate changes in vascular dysfunction and ED.