Decision tree analyses of key patient characteristics in Middle Eastern/North African and Latin American men treated with long-acting and short-acting PDE5 inhibitors for erectile dysfunction

Efficacy of Continuous Dosing of Tadalafil Once Daily vs Tadalafil On Demand in Clinical Subgroups of Men With Erectile Dysfunction: A Descriptive Comparison Using the Integrated Tadalafil Databases

Introduction

Various factors play a role in the development of erectile dysfunction (ED).

Aim

To provide a descriptive comparison of erectile function response for tadalafil on-demand (PRN) and once-daily (OAD) dosing regimens in patients with common comorbid conditions, treatments, or risk factors that can be considered when treating ED.

Methods

In total, 17 PRN and 4 OAD placebo-controlled studies were included in the integrated database in these pooled analyses. Data were analyzed from patients treated with placebo, tadalafil 10 mg (low dose), and 20 mg (high dose) for the PRN studies and placebo, tadalafil 2.5 mg (low dose), and 5 mg (high dose) for the OAD studies.

Main Outcome Measures

The effects of tadalafil were measured using the International Index of Erectile Function administered from baseline to week 12. A descriptive comparison of the efficacy of tadalafil PRN vs OAD was examined in the clinical populations.

Results

Baseline characteristics of 4,354 men were comparable between the PRN and OAD groups, with differences seen only in the variables of race, body mass index (BMI) of at least 30 kg/m², and alcohol use. Tadalafil was efficacious at improving erectile function for all clinical populations, except for the low-dose OAD group, which demonstrated a weaker effect vs placebo than the high-dose OAD group, and the low- and high-dose PRN groups vs placebo for patients with BMI of at least 30 kg/m² for patients without a cardiovascular disorder, smokers, patients with ED duration shorter than 1 year, and patients without previous phosphodiesterase type 5 inhibitor use. Tadalafil was efficacious for patients with or without diabetes mellitus, arterial hypertension, hyperlipidemia, and alcohol use at baseline.

Conclusion

Tadalafil OAD and PRN regimens showed efficacy in patients with ED. No clinical populations of patients with ED seemed to benefit overwhelmingly from one dose regimen over the other.

Comparisons of regular and on-demand regimen of PED5-Is in the treatment of ED after nerve-sparing radical prostatectomy for Prostate Cancer

Phosphodiesterase type-5 inhibitors (PDE5-Is) have been recommended as first line therapy for erectile dysfunction for patients received nerve-sparing radical prostatectomy for prostate cancer. We examed the efficiency of PDE5-Is and considered the optimal application. Systematic search of PubMed, Embase and the Cochrane Library was performed to identify all the studies. We identified 103 studies including 3175 patients, of which 14 were recruited for systematic review. Compared with placebo, PDE5-Is significantly ameliorated the International Index of Erectile Function-Erectile Function domain score (IIEF) scores (MD 4.89, 95% CI 4.25-5.53, p < 0.001). By network meta-analysis, sildenafil seems to be the most efficiency with a slightly higher rate of treatment-emergent adverse events (TEATs), whereas tadalafil had the lowest TEATs. In terms of IIEF scores, regular regimen was remarkably better than on-demand (MD 3.28, 95% CI 1.67-4.89, p < 0.001). Regular use was not associated with higher proportion of patients suffering TEATs compared with on-demand (RR 1.02, 95% CI 0.90-1.16, p = 0.72). Compared with placebo, PDE5-Is manifested significantly improved treatment outcomes. Overall, regular regimen demonstrated statistically pronounced better potency than on-demand. Coupled with the comparable rate of side effects, these findings support the regular delivery procedure to be a cost-effective option for patients.

Exploratory Decision-Tree Modeling of Data from the Randomized REACTT Trial of Tadalafil Versus Placebo to Predict Recovery of Erectile Function After Bilateral Nerve-Sparing Radical Prostatectomy

BACKGROUND

Understanding predictors for the recovery of erectile function (EF) after nerve-sparing radical prostatectomy (nsRP) might help clinicians and patients in preoperative counseling and expectation management of EF rehabilitation strategies.

OBJECTIVE

To describe the effect of potential predictors on EF recovery after nsRP by post hoc decision-tree modeling of data from A Study of Tadalafil After Radical Prostatectomy (REACTT).

DESIGN, SETTING, AND PARTICIPANTS

Randomized double-blind double-dummy placebo-controlled trial in 423 men aged <68 yr with adenocarcinoma of the prostate (Gleason ≤7, normal preoperative EF) who underwent nsRP at 50 centers from nine European countries and Canada.

INTERVENTION

Postsurgery 1:1:1 randomization to 9-mo double-blind treatment with tadalafil 5mg once a day (OaD), tadalafil 20mg on demand, or placebo, followed by a 6-wk drug-free-washout, and a 3-mo open-label tadalafil OaD treatment.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Three decision-tree models, using the International Index of Erectile Function-Erectile Function (IIEF-EF) domain score at the end of double-blind treatment, washout, and open-label treatment as response variable. Each model evaluated the association between potential predictors: presurgery IIEF domain and IIEF single-item scores, surgical approach, nerve-sparing score (NSS), and postsurgery randomized treatment group.

RESULTS AND LIMITATIONS

The first decision-tree model (n=422, intention-to-treat population) identified high presurgery sexual desire (IIEF item 12: ≥3.5 and <3.5) as the key predictor for IIEF-EF at the end of double-blind treatment (mean IIEF-EF: 14.9 and 11.1), followed by high confidence to get and maintain an erection (IIEF item 15: ≥3.5 and <3.5; IIEF-EF: 15.4 and 7.1). For patients meeting these criteria, additional non-IIEF-related predictors included robot-assisted laparoscopic surgery (yes or no; IIEF-EF: 19.3 and 12.6), quality of nerve sparing (NSS: <2.5 and ≥2.5; IIEF-EF: 14.3 and 10.5), and treatment with tadalafil OaD (yes and no; IIEF-EF: 17.6 and 14.3). Additional analyses after washout and open-label treatment identified high presurgery intercourse satisfaction as the key predictor.

CONCLUSIONS

Exploratory decision-tree analyses identified high presurgery sexual desire, confidence, and intercourse satisfaction as key predictors for EF recovery. Patients meeting these criteria might benefit the most from conserving surgery and early postsurgery EF rehabilitation. Strategies for improving EF after surgery should be discussed preoperatively with all patients; this information may support expectation management for functional recovery on an individual patient level.

PATIENT SUMMARY

Understanding how patient characteristics and different treatment options affect the recovery of erectile function (EF) after radical surgery for prostate cancer might help physicians select the optimal treatment for their patients. This analysis of data from a clinical trial suggested that high presurgery sexual desire, sexual confidence, and intercourse satisfaction are key factors predicting EF recovery. Patients meeting these criteria might benefit the most from conserving surgery (robot-assisted surgery, perfect nerve sparing) and postsurgery medical rehabilitation of EF.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT01026818.