To compare outcomes of men with or without calcified plaques undergoing collagenase Clostridium histolyticum (CCH) injections for Peyronie's disease (PD) and identify predictors of CCH success.

From March 2014 through January 2017, data were prospectively collected on 192 patients who underwent 1-4 cycles of CCH for the treatment of PD. Of these, 115 completed ≥2 CCH cycles and had data on curvature assessment. The primary outcome was the percentage of men with >20% improvement in composite curvature. Univariate analysis was performed to compare rate of success based on patient and disease characteristics, and multivariate logistic regression was used to identify predictors of successful treatment.

Calcified plaques were identified in 34 of 115 (30%) patients. Patients with calcified plaque were younger, had longer duration of disease, and higher rates of significant erectile dysfunction. On multivariate logistic regression controlling for calcification and degrees composite curvature, noncalcified plaque (odds ratio 2.50; 95% confidence interval 1.06-6.00; P = .03) and curvature ≥60° (odds ratio 5.01; 95% confidence interval 1.34-21.62; P = .02) were found to be significant predictors of ≥20% improvement in composite curvature. When differentiated by calcification severity, those with no calcification achieved significant improvements in curvature (28.1° vs 10.3°, P = .04), compared to moderate (shadowing) or severe (>1 cm).

Plaque calcification is associated with a significantly lower rate of success of CCH therapy for PD, while greater baseline curvature is associated with increased odds of successful curvature improvement.