Predictive Factors of Patients' and Their Partners' Sexual Function Improvement After Collagenase Clostridium Histolyticum Injection for Peyronie's Disease: Results From a Multi-Center Single-Arm Study
Authors: Cocci Andrea , Russo Giorgio Ivan , Salonia Andrea , Cito Gianmartin , Regis Federica , Polloni Gaia , Giubilei Gianluca , Cacciamani Giovanni , Capece Marco , Falcone Marco , Greco Isabella , Timpano Massimiliano , Minervini Andrea , Gacci Mauro , Cai Tommaso , Garaffa Giulio , Giammusso Bruno , Arcaniolo Davide , Mirone Vincenzo , Mondaini Nicola 
Published: April 2018

Abstract

Background
Collagenase Clostridium histolyticum (CCH; Xiapex) injections represent the only licensed medical treatment for Peyronie's disease (PD).

Aim
To evaluate the efficacy and safety of CCH injections in men with stable PD, using a modified treatment protocol and to assess partners' bother improvement in a large cohort of White-European sexually active heterosexual men treated in a single tertiary-referral center.

Methods
All the 135 patients enrolled underwent a thorough assessment, which included history taking, physical examination, and pharmacologically induced artificial erection test (intra-cavernous injection) to assess the degree of penile curvature (PC) at baseline and after the completion of the treatment. Patients with calcified plaque and/or ventral curvature were excluded. All patients underwent a modified treatment protocol, which consisted of 3 intra-lesional injections of 0.9 mg of CCH performed at 4-week intervals at the point of maximum curvature. After each injection, patients were instructed to follow a strict routine involving daily penile stretching in the intervals between injections.

Outcomes
International Index of Erectile Function (IIEF)–15, Global Assessment of PD, PD questionnaires (PDQ), and Female Sexual Function Index (FSFI) questionnaire were performed at baseline and at the end of treatment.

Results
Overall, 135 patients completed the study protocol. Before treatment, 18 (13.33%) partners showed a degree of sexual dysfunction. Baseline median IIEF–15, FSFI, and PDQ scores were, respectively, 59.0, 35.0, and 23.0. Overall, both IIEF–total and all domains significantly improved after treatment (all P &lt; .01). A PC mean change of 19.07 (P = .00) was measured. At the univariate linear regression analysis, IIEF–15, IIEF–erectile function, IIEF–sexual desire, and IIEF–intercourse satisfaction were positively associated with FSFI (all P ≤ .03); conversely, PDQ–penile pain, PDQ–symptom bother, and post-treament penile curvature (P ≤ .04) were associated with a decreased FSFI score. Furthermore, median change of PC was significantly associated with median change of FSFI (r = 0.25; 95% CI 0.02–0.11; P = .004). Global satisfaction after treatment was 89.6% (121/135).

Clinical Translation
This modified CCH treatment protocol could improve both patients' and partner's sexual function.

Strength and limitations
This was an open-label, single-arm clinical study, without placebo. where only heterosexual couples in stable relationships were included. Furthermore, no real assessment of female sexual distress was carried out and long-term sexual function in both patients and female partners were not taken into account.

Conclusions
The modified treatment schedule with CCH injections for stable PD has a positive impact on both patients' and partners' sexual function in heterosexual couples with a stable sexual relationship.