Multiple courses of intralesional collagenase injections for Peyronie disease: a retrospective analysis.

Background: In the original clinical trials evaluating intralesional collagenase Clostridium histolyticum for Peyronie disease (PD), treatment protocols were limited to 8 injections.

Aim: We sought to describe our single-center experience with the use of multiple rounds (>8 injections) of intralesional collagenase in patients with PD.

Methods: We conducted a retrospective analysis of all patients with PD receiving intralesional collagenase injections at our institution from October 2015 through December 2020. Some patients who completed 1 round of treatment elected to undergo additional rounds (16 or 24 injections) based on persistent curvature and presence of penile plaque. Clinical improvement was defined as a 20% reduction in penile curvature from the start of a given round of treatment to the end of that round of treatment. We measured erect penile curvature before and after each round and collected demographics, medical and surgical history, curvature outcomes, and treatment-related adverse events.

Outcome: The primary outcome was the reduction in penile curvature after multiple rounds of treatment with intralesional collagenase injections in patients with PD.

Results: A total of 330 patients underwent intralesional collagenase injections for PD, of whom 229 completed at least 8 injections and underwent pre- and posttreatment erect penile goniometry. An overall 42.8% (98/229), 38.6% (22/57), and 12.5% (1/8) of patients achieved clinical improvement after 1 round of therapy (8 injections), 2 rounds (16 injections), and 3 rounds (24 injections), respectively. Mean degree and mean percentage improvement of penile curvature for the start and end of each round of treatment were 8.3° and 16.4% (after 1 round), 7.2° and 16.8% (after 2 rounds), and 3.3° and 8.1% (after 3 rounds). Bruising was the most common complication, with an incidence of at least 50% in each round.

Clinical Implications: Knowledge of patient responses to multiple rounds of intralesional collagenase injections may help guide physicians in management and counseling of patients regarding PD treatment options.

Strengths And Limitations: This is the first study to evaluate multiple rounds (>8 injections) of intralesional collagenase for PD. Limitations include retrospective analysis and smaller sample size among patients undergoing 3 rounds (24 injections).

Conclusion: For patients who did not achieve clinical improvement after 1 round of treatment, an additional round may be beneficial. However, no real improvement was observed for patients undergoing a third round.