Predictors of treatment success after collagenase Clostridium histolyticum injection for Peyronie's disease: development of a nomogram from a multicentre single-arm, non-placebo controlled clinical study

OBJECTIVE To build a nomogram able to predict treatment success after collagenase Clostridium histolyticum (CCH) for Peyronie's disease (PD). MATERIALS AND METHODS Between November 2016 and November 2017, we enrolled 135 patients with PD into a multicentre single-arm prospective study. All patients enrolled received CCH treatment. Success of therapy was defined as a decrease in penile curvature (PC) of ≥20° from baseline. Treatment satisfaction was assessed using a scale from 1 to 10, and high satisfaction was arbitrarily defined as a score of ≥8. Calcification level was classified as: absence of calcification; low perilesional calcification; and high calcification. RESULTS The median (interquartile range [IQR]) patient age was 56.0 (45.0-65.0) years and the median (IQR) was PC was 30 (30.0-60.0)°. After the treatment protocol, we observed a significant median change in PC of -20.0° (P < 0.01). The median (IQR) PC improvement was 44 (28.0-67.0)%. Overall median (IQR) satisfaction score was 8.0 (7.0-9.0). Treatment efficacy was reported in a total of 77 patients (57.04%). When analysing factors associated with PC improvement after treatment, we found that baseline PC (odds ratio [OR] 1.14; P < 0.01), basal plaque (OR 64.27; P < 0.01), low calcification (OR 0.06; P < 0.01) and high calcification (OR 0.03; P < 0.01) were significant predictors of PC improvement. The c-index for the model was 0.93. CONCLUSIONS Patients with longer PD duration, greater baseline PC and basal plaque location had a greater chance of treatment success. These results could be applied to clinical practice before external validation of our nomogram.