Standards for clinical trials in male sexual dysfunction: Erectile dysfunction and rapid ejaculation

Introduction. The introduction of safe and effective therapies for sexual dysfunctions depend upon appropriate clinical protocol design, study procedures, data collection and analysis. Aim. To provide recommendations/guidelines concerning state-of-the-art knowledge for standards for clinical trials in sexual dysfunction in men, particularly in the areas of erectile dysfunction and rapid ejaculation. Methods. An International Consultation in collaboration with the major urology and sexual medicine associations assembled over 200 multidisciplinary experts from 60 countries into 17 committees. Committee members established specific objectives and scopes for various male and female sexual medicine topics. The recommendations concerning state-of-the-art knowledge in the respective sexual medicine topic represent the opinion of experts from five continents developed in a process over a 2-year period. Concerning the Standards for Clinical Trials in Male Sexual Dysfunction Committee, there were six experts from four countries. Main Outcome Measure. Expert opinion was based on grading of evidence-based medical literature, widespread internal committee discussion, public presentation and debate. Results. Drug development requires a multiphased approach. Phase I studies investigate multiple-dose safety, tolerability and pharmacokinetic issues. Phase 2 programs explore dose ranging (lowest effective, maximally tolerated and toxic doses). Phase 3 trials provide the substantial evidence including drug-drug interaction data and studies in special populations. Clinical studies require validated outcome assessment instruments conducted in defined but representative patient populations. Daily diaries or per-event questionnaires are patient-reported outcomes that assist in retrospective questionnaire interpretation. A qualified biostatistician should calculate the sample power for the trial, type of statistical model and design employed, use of covariate or subgroup analyses, and calculation of effect sizes. Conclusions. More research is needed in developing standards for use in the development of clinical trials and outcomes assessment researching either erectile dysfunction or rapid ejaculation.