A Randomized Phase II Trial of Flibanserin in Men Receiving Androgen Suppression for Prostate Cancer

Androgen deprivation therapy (ADT) is used to improve survival for men with metastatic and high risk localized prostate cancer. Unfortunately, ADT is also associated with a number of adverse effects, and sexual dysfunction occurs in nearly all men who receive this treatment. Sexual dysfunction is the most common complaint among men with prostate cancer and contributes to worse quality of life (QoL). The loss of sexual interest, in particular, is highly distressing for men with prostate cancer and their partners, which contributes additional psychological morbidity in these patients. Despite the importance of sexual health in men with prostate cancer, previous interventions to improve sexual interest in men receiving ADT have had little success, and new strategies are needed. We hypothesize that flibanserin can be used to increase sexual desire among men receiving ADT for prostate cancer. Flibanserin is a multifunctional serotonin receptor agonist/antagonist that acts as an agonist of post-synaptic 5-HT(1A) receptors and an antagonist of 5-HT(2A) receptors, that has previously been approved to treat hypoactive sexual desire disorder in women. In this proposal, we will conduct a double blind, placebo controlled, randomized phase II clinical trial to assess the efficacy and safety of flibanserin 100mg daily among men receiving ADT for prostate cancer. We will recruit 50 men with prostate cancer who are receiving ADT and also endorse reduced sexual interest to participate. Men will be randomized to receive either daily flibanserin 100mg or placebo for a 12-week period. Patient-reported frequency of attempted sexual intercourse, sexual QoL, global QoL, and toxicity will be assessed at baseline and at pre-specified time points. Specific Aim 1 will assess the efficacy of flibanserin. The frequency of attempted sexual intercourse among men receiving flibanserin will be compared to men receiving placebo. The change in patient reported sexual QoL will also be compared between the study groups. Specific Aim 2 will assess the safety and tolerance of flibanserin. The frequency of grade 3+ adverse events and study drug discontinuation among men receiving flibanserin will be reported. The frequency of grade 2+ and grade 3+ patient reported adverse events will be compared between the flibanserin and placebo groups. Accomplishing these specific aims will provide us with a preliminary understanding about use of flibanserin in men receiving ADT for prostate cancer. This study will be conducted by a qualified multidisciplinary team of investigators with experience in both clinical trials and cancer survivorship research at the University of Alabama at Birmingham O’Neal Comprehensive Cancer Center. The results of this clinical trial will be used to inform the design of a phase III clinical trial. Our long-term goal is to develop an evidence based treatment strategy that will significantly improve sexual health and QoL for prostate cancer survivors.