Factors associated with improved curvature outcomes with collagenase clostridium histolyticum for Peyronie's disease: results from a large prospective series.

Background: Since its release in 2014, collagenase clostridium histolyticum (CCH) has become the most commonly used injectable therapy for Peyronie's disease (PD). While some studies have suggested modest improvements in curvature with use of CCH, others have found more significant gains.

Aim: To determine predictors of improved curvature in men with PD treated with CCH.

Methods: A prospective, sequential database has been maintained of all men with PD undergoing CCH injections since 2014. Clinical characteristics and responses to standardized and nonstandardized questionnaires were collected at baseline, during, and after treatment.

Outcomes: Change in curvature was assessed using the "Most Recent" curvature assessment, and statistical analyses were performed to identify factors that correlated with greater curve improvements.

Results: A total of 826 men underwent at least one CCH series and comprise the current cohort. Univariate analysis demonstrated associations between greater curvature improvements in patients with more severe baseline curvature (0.5° greater improvement per increase in 1° baseline), hourglass deformities (3-10° greater improvement among moderate/severe men), number of CCH series administered (0-4° per series), strong nocturnal erections (11° higher), greater frequency of intercourse (0.6° per intercourse attempt per month), greater bother and psychological impact (as assessed by the Peyronie's Disease Questionnaire), and those who used RestoreX (5-20° depending on test). Worse outcomes were observed among men who self-reported decreased motivation (7°) as well as those with pure lateral curvatures (11°). Men who experienced hematomas, a popping sensation, and those with rapid detumescence during treatment also had more significant improvements in curvature (5°). On multivariate analysis, baseline curvature, lateral curve direction, hourglass/indentation deformities, RestoreX use, and suspected controlled penile fracture remained independently associated with better outcomes. Of all the factors assessed, RestoreX use was associated with the largest degree of improvement.

Clinical implications: These findings highlight several potential predictors of improved outcomes with CCH, which may be utilized by providers to help counsel patients deciding on medical versus surgical treatment of PD.

Strengths and limitations: The strengths include the largest single-center prospective database of PD patients undergoing CCH published to date and use of objective and validated instruments to track PD outcomes. Limitations include the single-center nature, diverse patient cohort, and change in CCH technique over time.

Conclusion: Several baseline and treatment-related factors correlate with CCH outcomes. These data may assist both patients and providers as they relate to patient selection and counseling. The data also suggest the importance of patient motivation and active participation during the treatment course.