Background: Previous studies of penile traction therapy (PTT) devices have demonstrated limited/no efficacy when combined with intralesional therapies for Peyronie's disease (PD). Recently, randomized data have demonstrated the efficacy of a novel PTT device, RestoreX, developed in cooperation with the Mayo Clinic, in men with PD. Aim: To assess the safety and efficacy of treatment with the RestoreX device plus collagenase Clostridium histolyticum (CCH) compared with CCH alone and CCH with other PTT devices. Methods: A prospective registry has been maintained of all men undergoing CCH injections for PD between March 2014 and January 2019. Assessments were performed at baseline, during each series, and after completion of treatment. Those completing therapy (8 injections or sooner if satisfied) were categorized into group 1 (CCH alone), group 2 (CCH plus any PTT device other than RestoreX), or group 3 (CCH plus RestoreX). Outcomes: Changes in penile length, curvature, and subjective perception and the occurrence of adverse events. Results: Of 287 men with data on PTT use, 113 had completed therapy with all objective data available and compose the current cohort. Baseline demographic and pathophysiological variables were similar among the 3 groups except penile length and previous PD medications. Following treatment, group 3 demonstrated significantly greater improvements in curvature (mean, 20.3 /31% for group 1, 19.2 /30% for group 2, and 33.8 / 49% for group 3), length (-0.7 cm/-4%, -0.4 cm/-2%, and þ1.9 cm/þ17%, respectively), and subjectively estimated curvature improvement (44%, 32%, and 63% respectively), despite shorter daily PTT use (0.9 vs 1.9 hours/day). Group 3 was more likely than the other groups to experience 20 , 20%, and 50% curvature improvements, 1 cm length gain, and 20% length improvement. All results were statistically significant for group 3 versus groups 1 and 2, but not between groups 1 and 2, even after controlling for baseline features and isolating a subset of 3 hours/day PTT use (group 2). Group 3 was 6.9 times more likely to achieve 20 curvature improvement, and 3.5 times more likely to achieve 50% curvature improvement, and 10.7 times more likely to experience 20% length improvement. Adverse events were similar among the 3 groups. Clinical Implications: Use of the RestoreX device enhances mean curvature outcomes by 71% and increases penile length in men with PD receiving CCH therapy. Strengths & Limitations: Study strengths include a prospective registry, consistent assessments, the largest single-site series with complete posttreatment outcomes reported to date, the largest PTT series reported to date, and a true-to-life clinical design. Limitations include the nonrandomized methodology and single-site setting. Conclusion: The combination of RestoreX and CCH is associated with significantly greater curvature and length improvements compared with CCH alone or CCH with other PTT devices. Alom M, Sharma KL, Toussi A, et al. Efficacy of Combined Collagenase Clostridium histolyticum and R...