The Use of Xiaflex on Downward Penile Curvatures

The Use of Xiaflex on Downward Penile Curvatures


Peyronie’s disease (PD) is a condition that involves plaques forming under the skin of the penis, causing penile abnormalities like indentations or curvature. While most often people with PD experience curvature that is upward or to one side, sometimes individuals have a ventral or downward curvature.

Collagenase Clostridium histolyticum (CCH), known commercially as Xiaflex, is an FDA-approved treatment for PD. It is an injectable medication that works by breaking down the plaques or hardened tissues that are contributing to PD.

Initial Xiaflex studies excluded individuals with ventral curvature due to safety concerns. However, despite early exclusion, CCH has been offered to patients with ventral curvatures since 2015, showing similar safety and efficacy as other curvatures.

A preliminary study of 25 ventral cases found comparable outcomes in terms of bruising and hematomas (pools of clotted blood), with no urethral injuries. A new analysis aimed to update and expand on these findings by reviewing outcomes in a larger cohort from 2014 to present, comparing safety and efficacy of using CCH on ventral and nonventral curvatures.


In February 2023, an analysis was conducted on a database of men who underwent intralesional CCH injections for Peyronie’s disease (PD) since March 2014. The database included all patients treated, creating a real-world representation. Patients were categorized based on penile curvature direction into ventral or nonventral cohorts.

The injection protocol evolved over time and included multiple components. Starting in 2015, men with ventral curvatures were treated with Xiaflex after thorough counseling on potential risks.

Assessments, including penile curvature evaluations and standardized questionnaires, were performed for all individuals at baseline and after CCH injections. Adverse events (AEs) were monitored, with specific attention to bruises and hematomas.

Statistical analyses compared baseline characteristics and outcomes between cohorts, utilizing two distinct definitions: one based on the most recent data available and another on men who completed all 8 CCH injections or discontinued due to satisfaction, aiming to provide a comprehensive understanding of treatment outcomes.


In the analysis, 560 PD patients were studied, comprising 85 with ventral curvature and 475 with nonventral curvature. Baseline characteristics were largely similar between groups, except for differences in penile length and Peyronie’s Disease Questionnaire (PDQ) scores. Median baseline penile curvature was 60.0° for ventral and 65.0° for nonventral cases.

The treatment protocol included CCH injections and adjunctive (additional) therapies. Changes in penile curvature were comparable between ventral and nonventral cohorts, with a trend towards greater improvement in ventral cases. Adverse events were also similar between groups, although hematomas were more frequent in ventral cases. No urethral injuries were reported.

The association with ventral direction became statistically insignificant in multivariable analysis, possibly due to the small sample size. Overall, the majority of patients reported meaningful improvements in their condition, highlighting the efficacy of CCH therapy in both ventral and nonventral PD cases.

Discussion & Conclusion

The results of this study highlight the effectiveness and safety of CCH injections in treating ventral penile curvature in PD patients. They indicate comparable or even greater improvements in ventral cases compared to curvatures in other directions. Changes in therapeutic techniques, such as adding Restorex penile traction therapy, have improved outcomes, particularly for some dorsal curvatures. Despite variations in protocols, Xiaflex injections remain generally safe, with no reported urethral complications. The study underscores CCH’s potential as a treatment option for PD across all curvature directions. It is important to note, however, that this medication is not currently available in Europe and some other locations around the globe, though it is available in the U.S.


  • Miller, J. A., Loeb, C. A., La, J., el Khatib, F., & Yafi, F. A. (2024). Penetrative anal intercourse may require high axial loading forces. The Journal of Sexual Medicine, 21(1), 40–43.

Members Only


ISSM Update