Open‐Label Extension Study of Flibanserin in Women with Hypoactive Sexual Desire Disorder

Role of flibanserin in managing hypoactive sexual desire disorder in women: A systematic review and meta-analysis

BACKGROUND

Flibanserin, approved for the treatment of hypoactive sexual desire disorder (HSDD) in females, has demonstrated diverse therapeutic and adverse effect (AE) prospects in the extant randomized controlled trials (RCTs). This meta-analysis aimed to characterize the outcomes of flibanserin use in these patients comprehensively.

METHODS

RCTs involving women with HSDD receiving flibanserin in the intervention arm and placebo in the control arm were sought after throughout the electronic databases. The primary outcomes were the changes from baseline in satisfying sexual events (SSE) per month and sexual desire score per month measured using an electronic diary (eDiary).

RESULTS

From 478 initially screened articles, data from 8 RCTs involving 7906 women with HSDD were analyzed. In premenopausal women, flibanserin 100 mg was superior to placebo in improving the number of SSE per month (mean difference, MD 0.69, 95% CI [0.39, 0.99]), eDiary sexual desire score (MD 1.71, 95% CI [0.43, 2.98]), Female Sexual Function Index (FSFI) desire domain (FSFI-d) score (MD 0.30, 95% CI [0.29, 0.31]), FSFI total score (MD 2.51, 95% CI [1.47, 3.55]), Female Sexual Distress Scale-Revised (FSDS-R) Item 13 score (MD -0.30, 95% CI [-0.31, -0.29]), and FSDS-R total score (MD -3.30, 95% CI [-3.37, -3.23]). Compared to placebo, a higher number of premenopausal women using flibanserin 100 mg achieved improvements in the Patient's Global Impression of Improvement score (OR 1.93, 95% CI [1.58, 2.36], P < .00001) and responded positively at Patient Benefit Evaluation (PBE) (odds ratio, OR 1.76, 95% CI [1.34, 2.31], P < .0001). Postmenopausal women receiving flibanserin 100 mg also benefited in terms of the number of SSE per month, FSFI-d and total scores, FSDS-R Item 13 and total scores, and PBE response. Although flibanserin use was associated with higher risks of dizziness, fatigue, nausea, somnolence, and insomnia, these adverse events were mild in nature; the serious AEs and severe AEs were comparable between the flibanserin and placebo groups.

CONCLUSION

While flibanserin has demonstrated efficacy in the treatment of HSDD in both pre- and postmenopausal women, its therapeutic advantages may be overshadowed by the higher likelihood of AEs.

Pharmacotherapy for female sexual dysfunctions (FSDs): what is on the market and where is this field heading?

INTRODUCTION

Female sexual dysfunctions (FSDs) are common in women of any age and have a huge impact on quality of life and relationships. They have a multifaceted etiology limiting the development of pharmacotherapies with a high rate of effectiveness. Safety issues are also a concern.

AREAS COVERED

The authors report the most recent advances in pharmacotherapy for premenopausal and postmenopausal women with a main focus on hypoactive sexual desire disorders (HSDD) and associated sexual symptoms. Good levels of evidence have emerged for psychoactive agents, such as flibanserin and bremelanotide, as well as hormonal compounds (transdermal testosterone). The authors also report briefly on intravaginal DHEA (prasterone), local estrogen therapy (LET), and ospemifene to manage effectively vulvovaginal atrophy/genitourinary syndrome of menopause (VVA/GSM). In addition, they discuss promising therapeutic options highlighting the main reasons that hamper the availability of new labeled products. Finally, they include the importance of the multimodal approach to address FSDs.

EXPERT OPINION

Approved pharmacotherapies for FSD are limited. Validated multidimensional instruments and adequate objective measures of physical and mental responses to sexual external and internal incentives are mandatory to identify women suitable to chronic or on-demand treatments and to assess their pattern of response in research and practice.

Female Sexual Function Following Radical Cystectomy in Bladder Cancer

INTRODUCTION

A clear and well-documented gender bias exists in the evaluation of sexual outcomes for women undergoing urologic surgery. Due to the anatomic template of anterior exenteration, women are commonly left with side effects that include sexual dysfunction and the perpetuated effects of surgical menopause.

OBJECTIVES

To present evaluation and treatment recommendations for female sexual dysfunction treatment and evaluation, in addition to surgical templates during radical cystectomy (RC).

METHODS

This article reviews current literature regarding sexual function and RC with urinary diversion in female bladder cancer patients. Furthermore, this review will provide a review of techniques for organ and neurovascular preservation, along with novel vaginal reconstruction templates. Our review will further focus on emerging technology, including minimally invasive surgery and organ and nerve preservation, directed at preservation of female sexual function.

RESULTS

Clinically, studies have demonstrated that females who have undergone genitalia-sparing and neurovascular preservation during RC regained sexual activity earlier than patients undergoing traditional RC. If organ and nerve preservation is not feasible due to involvement of trigone or bladder neck, vaginal reconstruction can mitigate the sexual dysfunction that results from a loss of the anterior vagina during a standard RC.

CONCLUSION

Female sexual dysfunction is associated with high levels of patient distress and is best comanaged with a multidisciplinary treatment approach, including preoperative counseling, intraoperative nerve, and organ preservation, and postoperative interventions to mitigate sexual side effects. Davis L, Isali I, Prunty M, et al. Female Sexual Function Following Radical Cystectomy in Bladder Cancer. Sex Med Rev 2021;XX:XXX-XXX.

A Systematic Literature Review of Health-related Quality of Life Measures for Women with Hypoactive Sexual Desire Disorder and Female Sexual Interest/Arousal Disorder

INTRODUCTION

Hypoactive Sexual Desire Disorder (HSDD) / Female Sexual Interest/Arousal Disorder (FSIAD) impacts health-related quality of life (HRQoL) of women and their partners, yet existing measures fail to adequately capture relevant concepts (ie, what is essential to measure including symptoms/impacts) important to women with HSDD/FSIAD.

OBJECTIVES

To identify HRQoL tools used to assess women with HSDD/FSIAD, and to evaluate their psychometric properties (ie, reliability, validity, and responsiveness).

METHODS

We conducted searches in PubMed, Embase and PsychINFO from June 5, 1989 to September 30, 2020 for studies in women with HSDD/FSIAD and psychometric analyses (English only). Principles of the Preferred Reporting Items for Systematic reviews and Meta-Analyses, the COnsensus-based Standards for the selection of health Measurement INstruments Risk of Bias Checklist and other psychometric criteria were applied. Based on this search, 56 papers were evaluated including 15 randomized-controlled trials, 11 observational/single arm/open label studies, and 30 psychometric studies.

RESULTS

Of the 18 measures identified, the Female Sexual Function Index (FSFI) and Female Sexual Distress Scale-Revised (FSDS-R) were included in most studies (> 50%). General HRQoL instruments were not used in any of the clinical trials; the SF-12, SF-36 and EQ-5D-5L were reported in two observational studies. No instruments achieved positive quality ratings across all psychometric criteria. The FSFI, FSDS-R, Sexual Event Diary (SED) and the Sexual Desire Relationship Distress Scale (SDRDS), were the only measures to receive a positive rating for content validity.

CONCLUSION

Reliable and valid HRQoL measures that include sexual desire and distress are needed to provide a more systematic and comprehensive assessment of HRQoL and treatment benefits in women with HSDD/FSIAD. While inferences about HRQoL are limited due to the lack of uniformity in concepts assessed and limited psychometric evaluation of these measures in women with HSDD/FSIAD, opportunities exist for the development of reliable and validated tools that comprehensively measure the most relevant and important concepts in women with HSDD/FSIAD. Lim-Watson MZ, Hays RD, Kingsberg S, et al. A systematic literature review of health-related quality of life measures for women with Hypoactive Sexual Desire Disorder and Female Sexual Interest/Arousal Disorder. Sex Med Rev 2021;XX:XXX-XXX.

International Union of Basic and Clinical Pharmacology. CX. Classification of Receptors for 5-hydroxytryptamine; Pharmacology and Function

5-HT receptors expressed throughout the human body are targets for established therapeutics and various drugs in development. Their diversity of structure and function reflects the important role 5-HT receptors play in physiologic and pathophysiological processes. The present review offers a framework for the official receptor nomenclature and a detailed understanding of each of the 14 5-HT receptor subtypes, their roles in the systems of the body, and, where appropriate, the (potential) utility of therapeutics targeting these receptors. SIGNIFICANCE STATEMENT: This review provides a comprehensive account of the classification and function of 5-hydroxytryptamine receptors, including how they are targeted for therapeutic benefit.

Treatment of Hypoactive Sexual Desire Disorder Among Women: General Considerations and Pharmacological Options

Hypoactive sexual desire disorder (HSDD) is a persistent or recurrent absence of sexual fantasies and desire for sexual activity, causing marked personal distress or interpersonal difficulties. HSDD affects 10% of U.S. women and is associated with depression and other negative emotional states. It is imperative that psychiatrists are competent to make this diagnosis and are aware of available treatment options. A full psychiatric and medical history are necessary to identify potential causes or contributing factors that may need to be addressed first. The authors discuss the diagnostic tools available as well as general diagnostic considerations for psychiatrists. Given its importance in the understanding of the available treatments for this disorder, the pathophysiology behind HSDD is reviewed. The authors emphasize the treatment of HSDD, including general treatment considerations, treatment in the context of depression, and psychotherapy and medications that have been approved by the U.S. Food and Drug Administration.

Reliability and validity of the elements of desire questionnaire in premenopausal women with hypoactive sexual desire disorder

Background

The Elements of Desire Questionnaire (EDQ) is a patient-reported outcome (PRO) measure developed to evaluate sexual desire and was included in two identically designed phase 3 clinical trials (RECONNECT) as an exploratory endpoint. The EDQ was developed based on a literature review, qualitative research with patients with hypoactive sexual desire disorder (HSDD), and input from clinical experts. This instrument is intended to be used to collect efficacy data in clinical trials evaluating potential treatments for HSDD. The objective of this study was to evaluate the measurement properties of both the monthly and daily recall versions of the EDQ during the RECONNECT trials.

Methods

Participants completed the EDQ daily version for 7 consecutive days prior to selected monthly clinic visits. The monthly recall version was completed at each monthly clinic visit. The analysis population consisted of all subjects with Female Sexual Function Index (FSFI) data at baseline and ≥ 1 follow-up visit.

Results

At baseline, 1144 and 676 subjects completed the monthly and daily recall EDQs, respectively. The EDQ scores had good internal consistency and test-retest reliability. Monthly and daily recall EDQ scores were correlated with FSFI-desire domain scores at baseline and month 3. Scores from the monthly and daily recall versions were also correlated. After 6 months, there was a significantly greater improvement for bremelanotide versus placebo in both the monthly and daily recall versions (both P < 0.0001).

Conclusions

The results demonstrated that EDQ exhibited good reliability, validity, and sensitivity to change. Consistent with other validated PRO measures of sexual desire, the EDQ provides additional insights into sexual desire.

Trial registration

NCT02338960 and NCT02333071 (RECONNECT studies).

A rapid and sensitive UPLC-MS/MS method for the determination of flibanserin in rat plasma: application to a pharmacokinetic study

Background

In this work, we aim to develop and validate a fast, simple, and sensitive method for the quantitative determination of flibanserin and the exploration of its pharmacokinetics.

Methods

Ultra-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) was the method of choice for this investigation and carbamazepine was selected as an internal standard (IS). The plasma samples were processed by one-step protein precipitation using acetonitrile. The highly selective chromatographic separation of flibanserin and carbamazepine (IS) was realised using an Agilent RRHD Eclipse Plus C18 (2.1 × 50 mm, 1.8 µ) column with a gradient mobile phase consisting of 0.1% formic acid in water and acetonitrile. The analytes were detected using positive-ion electrospray ionization mass spectrometry via multiple reaction monitoring (MRM). The target fragment ions were m/z 391.3 → 161.3 for flibanserin and m/z 237.1 → 194 for carbamazepine (IS). The method was validated by linear calibration plots over the range of 100-120,000 ng/mL for flibanserin (R² = 0.999) in rat plasma.

Results

The extraction recovery of flibanserin was in the range of 91.5-95.8%. The determined inter- and intra-day precision was below 12.0%, and the accuracy was from - 6.6 to 12.0%. No obvious matrix effect and astaticism was observed for flibanserin. The target analytes were long-lasting and stable in rat plasma for 12 h at room temperature, 48 h at 4 °C, 30 days at - 20 °C, as well as after three freeze-thaw cycles (from - 20 °C to room temperature). The proposed method has been fully validated and successfully applied to the pharmacokinetic study of flibanserin.

Flibanserin for Premenopausal Hypoactive Sexual Desire Disorder: Pooled Analysis of Clinical Trials

Background: Flibanserin, a 5-hydroxytryptamine 5-HT_1A agonist and 5-HT_2A antagonist, is indicated for the treatment of acquired, generalized hypoactive sexual desire disorder (HSDD) in premenopausal women. This post hoc analysis assessed pooled efficacy and safety data for flibanserin in premenopausal women with HSDD. Materials and Methods: Data for flibanserin 100 mg once daily at bedtime (qhs) and placebo were pooled from three pivotal 24-week, randomized, placebo-controlled, multicenter studies (VIOLET, DAISY, and BEGONIA) of premenopausal women with HSDD. Pooled efficacy endpoints included the change from baseline to study end (i.e., 24 weeks) in the number of satisfying sexual events (SSEs) over 28 days, the Female Sexual Function Index desire domain (FSFI-d) score, and the Female Sexual Distress Scale-Revised Item 13 (FSDS-R-13) score. Results: The analysis included 2465 women (flibanserin, n = 1227; placebo, n = 1238) with a mean age of 36 years and a mean HSDD duration of 56.5 months. The mean ± standard error (SE) change from baseline to study end in SSEs over 28 days for flibanserin versus placebo was 2.1 ± 0.14 versus 1.2 ± 0.11, respectively (p < 0.0001). The least-squares mean ± SE changes from baseline to study end in FSFI desire domain score and FSDS-R-13 score were also significantly greater for flibanserin versus placebo (FSFI desire domain: 0.9 ± 0.04 vs. 0.6 ± 0.04, p < 0.0001; FSDS-R-13: -0.9 ± 0.04 vs. -0.6 ± 0.04, p < 0.0001). Patients in the flibanserin group generally had significantly greater improvements, compared with placebo, in SSEs, FSFI-d score, and FSDS-R-13 in subgroup analyses based on selected demographic and baseline clinical characteristics. Adverse events occurring in ≥10% of patients included dizziness and somnolence. Conclusions: This pooled analysis of three pivotal trials demonstrated that flibanserin 100 mg qhs was well tolerated, improved sexual desire, and reduced sexual distress associated with HSDD in premenopausal women, and these improvements were generally consistent across various subgroups based on demographic and baseline characteristics.

[Sexual disorders in the renal patient]

Quality of Life Related to Health is currently considered one of the primary therapeutic objectives in renal failure patients who need substitution treatment as life prolonging therapy. Sexual health is a basic right that positively affects the quality of life. Although a significant percentage of chronic patients have some type of sexual dysfunction, this is not openly discussed, making it important for doctors to address these issues in the clinic. A review is presented on the pathophysiology of sexual dysfunctions in both male and female chronic renal patients. The effects of dialysis and transplantation on sexual function will be addressed, as well as presenting the main sexual dysfunctions and their treatment.

Evaluation and Management of Hypoactive Sexual Desire Disorder

INTRODUCTION

Hypoactive sexual desire disorder (HSDD) often has a negative impact on the health and quality of life of women; however, many women do not mention-let alone discuss-this issue with their physicians. Providers of gynecologic services have the opportunity to address this subject with their patients.

AIM

To review the diagnosis and evidence-based treatment of low sexual desire in women with a focus on strategies that can be used efficiently and effectively in the clinic.

METHODS

The Medline database was searched for clinically relevant publications on the diagnosis and management of HSDD.

RESULTS

HSDD screening can be accomplished during an office visit with a few brief questions to determine whether further evaluation is warranted. Because women's sexual desire encompasses biological, psychological, social, and contextual components, a biopsychosocial approach to evaluating and treating patients with HSDD is recommended. Although individualized treatment plan development for patients requires independent medical judgment, a simple algorithm can assist in the screening, diagnosis, and management of HSDD. Once a diagnosis of HSDD has been made, interventions can begin with office-based counseling and progress to psychotherapy and/or pharmacotherapy. Flibanserin, a postsynaptic 5-hydroxytryptamine 1A agonist and 2A antagonist that decreases serotonin levels and increases dopamine and norepinephrine levels, is indicated for acquired, generalized HSDD in premenopausal women and is the only agent approved in the United States for the treatment of HSDD in women. Other strategies to treat HSDD include using medications indicated for other conditions (eg, transdermal testosterone, bupropion). Bremelanotide, a melanocortin receptor agonist, is in late-stage clinical development.

CONCLUSIONS

Providers of gynecologic care are uniquely positioned to screen, counsel, and refer patients with HSDD. Options for pharmacotherapy of HSDD are currently limited to flibanserin, approved by the US Food and Drug Administration, and off-label use of other agents. Clayton AH, Kingsberg SA, Goldstein I. Evaluation and Management of Hypoactive Sexual Desire Disorder. Sex Med 2018;6:59-74.

Sexual Activity in Patients with Cardiac Diseases

SUMMARY – In this article, we outline the latest guidelines published by the American Heart Association on sexual activity in patients with coronary artery disease, heart failure, structural heart diseases, arrhythmias, implanted pacemakers or cardioverter defibrillators, as well as on treatment options of sexual dysfunction. Sexual activities are similar to mild/moderate physical activity during a short period. Most patients are recommended to involve in sexual activity after prior comprehensive evaluation of physical condition. Those with stable cardiac symptoms and good functional capacity are at a low risk of adverse cardiovascular events, and others require treatment or stabilization before involving in sexual activity. Stress testing is useful in evaluating safety of sexual activity in patients with questionable or undetermined risk. Treatment of sexual dysfunction includes counseling of patients and their sexual partners, and drug treatment with phosphodiesterase inhibitors (sildenafil, tadalafil, vardenafil) which have been demonstrated to be safe and effective, in men, and with serotonin reuptake inhibitors (flibanserin) and local vaginal estrogen administration in women. In conclusion, in routine clinical practice, patients should be approached individually and multidisciplinarily in order to detect and eliminate the factors that interfere with normal sexual activities and disturb the quality of life.

Effects of Flibanserin on the Pharmacokinetics of a Combined Ethinylestradiol/Levonorgestrel Oral Contraceptive in Healthy Premenopausal Women: A Randomized Crossover Study

PURPOSE

This study aimed to investigate the effect of steady-state exposure to flibanserin, a 5-HT_1A agonist/5-HT_2A antagonist approved for the treatment of hypoactive sexual desire disorder in premenopausal women, on the single-dose pharmacokinetics of the contraceptive steroids ethinylestradiol and levonorgestrel in healthy premenopausal women.

METHODS

Healthy female volunteers (N = 24) received 2 single doses of a combined oral contraceptive containing ethinylestradiol 30 μg and levonorgestrel 150 μg, either alone (reference) or preceded by treatment with flibanserin 100 mg once daily for 14 days (test). The 2 treatments were given in randomized order, with a 4-week washout period following the last administration of the first treatment. Plasma concentrations of ethinylestradiol and levonorgestrel were measured over 48 hours after dosing for the determination of pharmacokinetic parameters; the primary end points were C_max and AUC_0-∞ of ethinylestradiol and levonorgestrel.

FINDINGS

Of the 24 women enrolled (mean age, 38.0 years), 23 completed the study. Mean (SD) C_max and AUC_0-∞ values of ethinylestradiol were 66.7 (16.3) pg/mL and 693 (268) pg · h/mL, respectively, following the oral contraceptive alone, and 72.7 (25.5) pg/mL and 740 (235) pg · h/mL, respectively, when the oral contraceptive was preceded by flibanserin. In both cases, the 90% CIs of the reference/test ratios of C_max and AUC_0-∞ were within the range of 80% to 125%, indicating that flibanserin had no significant effect on the pharmacokinetic properties of ethinylestradiol. Similarly, the mean (SD) C_max and AUC_0-∞ values of levonorgestrel were 5.0 (1.6) ng/mL and 52.2 (18.7) ng · h/mL, respectively, with the oral contraceptive alone, and 5.0 (1.6) ng/mL and 53.3 (20.4) ng · h/mL, respectively, following flibanserin; again, in both cases, the 90% CIs of the reference/test ratios were within the range of 80% to 125%, indicating that flibanserin had no significant effect on the pharmacokinetic properties of levonorgestrel. All adverse events were mild to moderate in intensity (incidence: 12.5% and 70.8% with ethinylestradiol/levonorgestrel treatment alone and following administration of flibanserin, respectively).

IMPLICATIONS

Pretreatment with flibanserin 100 mg once daily for 2 weeks did not produce a clinically relevant change in oral contraceptive drug exposure following single-dose administration of ethinylestradiol/levonorgestrel. This finding is relevant to women with hypoactive sexual desire disorder who might prefer oral contraceptives to other forms of birth control. EudraCT No: 2006-006960-46.

Female sexual dysfunction: a focus on flibanserin

Flibanserin is the first US Food and Drug Administration (FDA)-approved option for sexual dysfunction, specifically low sexual desire. Until recently, there were no FDA-approved medication options to assist the ~40% of women affected by female sexual dysfunction (FSD). Often, patients report feeling uncomfortable discussing sexual health, identifying a strong need for health care professionals (HCPs) to proactively reach out to patients to identify concerns and initiate a discussion about sexual health and the available treatment options. Within the Diagnostic and Statistical Manual of Mental Disorders, 5th Edition (DMS-5), the criteria of female sexual interest/arousal disorder (FSIAD) are outlined, encompassing one of the most common sexual concerns, formerly in its own category defined as hypoactive sexual desire disorder (HSDD) or low sexual desire. HSDD is the absence or deficiency of sexual interest and/or desire leading to significant distress and interpersonal difficulties. HCPs offer an important service in assessing their patients and providing information about treatment considerations while ensuring patient comfort with this topic. This article provides an overview of the types and potential causes associated with FSD and the role of flibanserin in practice as a treatment option. Despite a need for additional study in diverse populations, flibanserin has demonstrated efficacy with increased female sexual function index (FSFI) total and desire domain scores in clinical studies indicating benefit in sexual desire. Common patient or provider-administered assessment tools to assist in identifying affected patients and patient counseling strategies are reviewed.

Effect of Flibanserin Treatment on Body Weight in Premenopausal and Postmenopausal Women with Hypoactive Sexual Desire Disorder: A Post Hoc Analysis

BACKGROUND

Flibanserin, a 5-HT_1A agonist and 5-HT_2A antagonist, is indicated for the treatment of acquired, generalized hypoactive sexual desire disorder (HSDD) in premenopausal women. This post hoc analysis evaluated the effect of flibanserin treatment on body weight in premenopausal and postmenopausal women with HSDD.

MATERIALS AND METHODS

This analysis included three 24-week, double-blind, placebo-controlled studies of flibanserin 100 mg each bedtime (qhs) in premenopausal women, a similarly designed study in postmenopausal women, and a 52-week, open-label extension study in premenopausal women.

RESULTS

In a pooled analysis of premenopausal women, mean baseline body mass index (BMI) was 27.0 kg/m² in the flibanserin group (n = 1227) and 26.8 kg/m² in the placebo group (n = 1238). Among patients who completed 24 weeks of treatment, least squares (LS) mean weight change was -1.4 kg in the flibanserin group (n = 1010) and -0.1 kg in the placebo group (n = 1066; p < 0.0001). Weight loss ≥5% from baseline was reported in 21.0% of patients who received flibanserin and 7.8% of patients who received placebo; weight loss ≥10% was reported in 3.8% and 2.0% of patients, respectively. In postmenopausal women, mean baseline BMI was 27.7 kg/m² in the flibanserin group (n = 467) and 27.3 kg/m² in the placebo group (n = 480). LS mean weight change at week 24 was -1.8 kg in the flibanserin group (n = 385) and -0.1 kg in the placebo group (n = 425; p < 0.0001), with weight loss ≥5% reported in 24.7% and 7.3% of patients, respectively, and weight loss ≥10% reported in 5.2% and 1.7%, respectively. In HSDD patients with >12 months (n = 880) and >18 months (n = 637) of exposure to flibanserin, mean weight change was -1.0 and -1.2 kg, respectively; 25.4% and 26.9% of patients, respectively, experienced weight loss ≥5% from baseline, and 7.8% and 8.4%, respectively, experienced weight loss ≥10%.

CONCLUSIONS

Women treated with flibanserin for HSDD may experience weight loss.

New developments in the treatment of hypoactive sexual desire disorder - a focus on Flibanserin

The objective of the authors is to highlight the historical complexities for the diagnosis and treatment of hypoactive sexual desire disorder (HSDD) with a focus on Flibanserin. A systematic review of the medical literature published in PubMed using the search terms HSDD and Flibanserin was conducted. Each author reviewed the results of the systematic review for articles to include in this study. HSDD is defined as a persistent or recurrent deficiency or absence of sexual fantasies and desire for sexual activity causing marked distress or interpersonal difficulty that is not better accounted for by another diagnosis. Until 2015, only homeopathic products and off-label use of prescription medications were medical treatment options for women with HSDD. Flibanserin, approved by the US Food and Drug Administration (FDA) in 2015, is the first to target female HSDD in premenopausal women. Flibanserin is a centrally acting nonhormonal oral medication taken once daily that affects serotonin, dopamine and norepinephrine levels, the key neurotransmitters in the biology of desire. Understanding prescribing guidelines and awareness of black box warnings is paramount for prescribers. Adherence to proper oversight will ensure Flibanserin can fulfil an unmet need for an FDA approved prescription medication for the treatment of HSDD in premenopausal women.

Flibanserin: First Global Approval

Flibanserin (Addyi™) is chemically described as a benzimidazole and is being developed by Sprout Pharmaceuticals for the treatment of hypoactive sexual desire disorder (HSDD). The drug has a high affinity for serotonin 5-HT1A and 5-HT2A receptors (5-HT1A agonist/5-HT2A antagonist) and is believed to treat HSDD by increasing levels of dopamine and noradrenaline and lowering levels of serotonin in the brain. Flibanserin has been approved in the USA for the treatment of premenopausal women with acquired, generalized HSDD. Earlier phase III development of the agent for HSDD in the EU and Canada had been discontinued by Boehringer Ingelheim, following regulatory feedback. Boehringer Ingelheim had also evaluated flibanserin for the treatment of depression but, due to displaying very mild antidepressant activity, its development in this indication was discontinued. This article summarizes the milestones in the development of flibanserin leading to its first approval for HSDD.

Retinal Neuroprotective Effects of Flibanserin, an FDA-Approved Dual Serotonin Receptor Agonist-Antagonist

PURPOSE

To assess the neuroprotective effects of flibanserin (formerly BIMT-17), a dual 5-HT1A agonist and 5-HT2A antagonist, in a light-induced retinopathy model.

METHODS

Albino BALB/c mice were injected intraperitoneally with either vehicle or increasing doses of flibanserin ranging from 0.75 to 15 mg/kg flibanserin. To assess 5-HT1A-mediated effects, BALB/c mice were injected with 10 mg/kg WAY 100635, a 5-HT1A antagonist, prior to 6 mg/kg flibanserin and 5-HT1A knockout mice were injected with 6 mg/kg flibanserin. Injections were administered once immediately prior to light exposure or over the course of five days. Light exposure lasted for one hour at an intensity of 10,000 lux. Retinal structure was assessed using spectral domain optical coherence tomography and retinal function was assessed using electroretinography. To investigate the mechanisms of flibanserin-mediated neuroprotection, gene expression, measured by RT-qPCR, was assessed following five days of daily 15 mg/kg flibanserin injections.

RESULTS

A five-day treatment regimen of 3 to 15 mg/kg of flibanserin significantly preserved outer retinal structure and function in a dose-dependent manner. Additionally, a single-day treatment regimen of 6 to 15 mg/kg of flibanserin still provided significant protection. The action of flibanserin was hindered by the 5-HT1A antagonist, WAY 100635, and was not effective in 5-HT1A knockout mice. Creb, c-Jun, c-Fos, Bcl-2, Cast1, Nqo1, Sod1, and Cat were significantly increased in flibanserin-injected mice versus vehicle-injected mice.

CONCLUSIONS

Intraperitoneal delivery of flibanserin in a light-induced retinopathy mouse model provides retinal neuroprotection. Mechanistic data suggests that this effect is mediated through 5-HT1A receptors and that flibanserin augments the expression of genes capable of reducing mitochondrial dysfunction and oxidative stress. Since flibanserin is already FDA-approved for other indications, the potential to repurpose this drug for treating retinal degenerations merits further investigation.

Bremelanotide for female sexual dysfunctions in premenopausal women: a randomized, placebo-controlled dose-finding trial

Aim: Evaluate efficacy/safety of bremelanotide (BMT), a melanocortin-receptor-4 agonist, to treat female sexual dysfunctions in premenopausal women. Methods: Patients randomized to receive placebo or BMT 0.75, 1.25 or 1.75 mg self-administered subcutaneously, as desired, over 12 weeks. Primary end point was change in satisfying sexual events/month. Secondary end points included total score changes on female sexual function index and female sexual distress scale-desire/arousal/orgasm. Results: Efficacy data, n = 327. For 1.25/1.75-mg pooled versus placebo, mean changes from baseline to study end were +0.7 versus +0.2 satisfying sexual events/month (p = 0.0180), +3.6 versus +1.9 female sexual function index total score (p = 0.0017), −11.1 versus −6.8 female sexual distress scale-desire/arousal/orgasm total score (p = 0.0014). Adverse events: nausea, flushing, headache. Conclusion: In premenopausal women with female sexual dysfunctions, self-administered, as desired, subcutaneous BMT was safe, effective, and well tolerated (NCT01382719).

Preclinical Abuse Potential Assessment of Flibanserin: Effects on Intracranial Self-Stimulation in Female and Male Rats

INTRODUCTION

Flibanserin is a serotonin receptor subtype 1A agonist and 2A antagonist that has been approved by the Food and Drug Administration for treating female sexual interest and arousal disorder. Little is known about the abuse potential of flibanserin.

AIM

To examine abuse-related effects of flibanserin in rats using an intracranial self-stimulation (ICSS) procedure previously used to evaluate the abuse potential of other drugs.

METHODS

Adult female and male Sprague-Dawley rats with electrodes implanted in the medial forebrain bundle were trained to press a lever for electrical brain stimulation under a "frequency-rate" ICSS procedure. In this procedure, increasing frequencies of brain stimulation maintain increasing rates of responding. Drugs of abuse typically increase (or "facilitate") ICSS rates and produce leftward and upward shifts in ICSS frequency-rate curves, whereas drugs that lack abuse potential typically do not alter or only decrease ICSS rates. Initial studies determined the potency and time course of effects on ICSS produced by acute flibanserin administration (1.0, 3.2 and 10.0 mg/kg). Subsequent studies determined the effects of flibanserin (3.2-18 mg/kg) before and after a regimen of repeated flibanserin administration (5.6 mg/kg/d for 5 days). Effects of the abused stimulant amphetamine (1.0 mg/kg) were examined as a positive control.

MAIN OUTCOME MEASURES

Flibanserin effects on ICSS frequency-rate curves in female and male rats were examined and compared with the effects of amphetamine.

RESULTS

Baseline ICSS frequency-rate curves were similar in female and male rats. Acute and repeated administrations of flibanserin produced only decreases in ICSS rates, and rate-decreasing effects of the highest flibanserin dose (10 mg/kg) were greater in female than in male rats. In contrast to flibanserin, amphetamine produced an abuse-related increase in ICSS rates that did not differ between female and male rats.

CONCLUSION

These results suggest that flibanserin has low abuse potential. In addition, this study suggests that female rats might be more sensitive than male rats to the rate-decreasing effects of high flibanserin doses.

Flibanserin

OBJECTIVE

To review pivotal clinical trials, pharmacology, contraindications, precautions, and key patient education points of flibanserin for the treatment of hypoactive sexual desire disorder (HSDD) in premenopausal women.

DATA SOURCES

A literature search of PubMed using the key words flibanserin and HSDD was conducted in September 2015. There was no time frame to exclude relevant clinical trials. All trials referenced were published between March 2012 and June 2014. Other relevant information was obtained from the Food and Drug Administration (FDA) Web site, press releases, prescribing information from the manufacturer, and ClinicalTrials.gov .

STUDY SELECTION/DATA EXTRACTION

All articles in the English language and involving human subjects were reviewed.

DATA SYNTHESIS

There are three 24-week, multicenter, randomized, double-blind, placebo-controlled trials that evaluated the efficacy of flibanserin in North American premenopausal women with HSDD. There was 1 trial that studied the effects of flibanserin in postmenopausal women. In all of the trials, the investigators found statistical significant improvements in Female Sexual Function Index (FSFI) desire domain score and satisfying sexual events (SSEs). The most frequently reported adverse events in all flibanserin arms of treatment were somnolence, dizziness, and nausea.

CONCLUSION

Flibanserin, a novel, nonhormonal agent that modulates excitatory and inhibitory neurotransmitters was studied in premenopausal women and has shown efficacy in improving sexual desire and SSEs.

First Pharmacological Therapy for Hypoactive Sexual Desire Disorder in Premenopausal Women

Objective: To review data regarding flibanserin, a recently approved therapy for hypoactive sexual desire disorder (HSDD). Data Sources: Literature search of MEDLINE (September 1995 to November 2015) was performed using the search term flibanserin. Reference lists from included articles were reviewed for pertinent citations. Study Selection and Data Extraction: We included phase-3 trials of flibanserin as a treatment for HSDD. Four reports of phase-3 trials were included. One extension study of four phase-3 trials and one phase-2 pharmacokinetic trial were also included. Data Synthesis: Though a strong placebo response was demonstrated, flibanserin consistently, yet marginally, showed improvement (compared with placebo) in the number of satisfying sexual events per month. The most common adverse events were dizziness (11.4%), somnolence (11.2%), nausea (10.4%), fatigue (9.2%), insomnia (4.9%), and dry mouth (2.4%). Conclusions: Flibanserin is effective in the treatment of HSDD. Flibanserin should be administered at bedtime to limit the risk for hypotension/syncope, accidental injury, and central nervous system (CNS) depression. Concomitant alcohol use contributes to significant CNS depression and hypotension/syncope with flibanserin and should be avoided according to the boxed warning. Careful patient assessment prior to the diagnosis of HSDD and the use of flibanserin is needed for safe use. Prescribing guidelines recommend discontinuing flibanserin at 8 weeks in the absence of benefit. Sexual dysfunction should be addressed in a patient-specific manner. Providers should exercise shared decision making in prescribing flibanserin for HSDD and discuss flibanserin’s benefits and alternative options.

Flibanserin-Stimulated Partner Grooming Reflects Brain Metabolism Changes in Female Marmosets

INTRODUCTION

Female sexual interest and arousal disorder is personally distressing for women. To better understand the mechanism of the candidate therapeutic, flibanserin, we determined its effects on an index of brain glucose metabolism.

AIM

We hypothesized that chronic treatment with flibanserin would alter metabolism in brain regions associated with serotonergic function and female sexual behavior.

METHODS

In a crossover design, eight adult female common marmosets (Calithrix jacchus) received daily flibanserin or vehicle. After 7-12 weeks of treatment, the glucose metabolism radiotracer [(18) F]fluorodeoxyglucose (FDG) was administered to each female immediately prior to 30 minutes of interaction with her male pairmate, after which females were anesthetized and imaged by positron emission tomography. Whole-brain normalized images were analyzed with anatomically defined regions of interest. Whole-brain voxelwise mapping was used to explore treatment effects. Correlations were examined between alterations in metabolism and pairmate social grooming.

MAIN OUTCOME MEASURES

Changes in metabolism associated with flibanserin were determined for dorsal raphe, medial prefrontal cortex (mPFC), medial preoptic area of hypothalamus (mPOA), ventromedial nucleus of hypothalamus, and field cornu ammonis 1 (CA1) of the hippocampus.

RESULTS

In response to chronic flibanserin, metabolism in mPOA declined, and this reduction correlated with increases in pairmate grooming. A cluster of voxels in frontal cortico-limbic regions exhibited reduced metabolism in response to flibanserin and overlapped with a voxel cluster in which reductions in metabolism correlated with increases in pairmate grooming. Finally, reductions in mPOA metabolism correlated with increases in metabolism in a cluster of voxels in somatosensory cortex.

CONCLUSIONS

Taken together, these results suggest that flibanserin-induced reductions in female mPOA neural activity increase intimate affiliative behavior with male pairmates.

The Female Sexual Response: Current Models, Neurobiological Underpinnings and Agents Currently Approved or Under Investigation for the Treatment of Hypoactive Sexual Desire Disorder

How a woman responds to sexual cues is highly dependent on a number of distinct, yet related, factors. Researchers have attempted to explain the female sexual response for decades, but no single model reigns supreme. Proper female sexual function relies on the interplay of somatic, psychosocial and neurobiological factors; misregulation of any of these components could result in sexual dysfunction. The most common sexual dysfunction disorder is hypoactive sexual desire disorder (HSDD). HSDD is a disorder affecting women across the world; a recent in-person diagnostic interview study conducted in the USA found that an estimated 7.4% of US women suffer from HSDD. Despite the disorder's prevalence, it is often overlooked as a formal diagnosis. In a survey of primary care physicians and obstetrics/gynaecology specialists, the number one reason for not assigning an HSDD diagnosis was the lack of a safe and effective therapy approved by the US Food and Drug Administration (FDA). This changed with the recent FDA approval of flibanserin (Addyi™) for the treatment of premenopausal women with acquired, generalized HSDD; there are still, however, no treatments approved outside the USA. HSDD is characterized by a marked decrease in sexual desire, an absence of motivation (also known as avolition) to engage in sexual activity, and the condition's hallmark symptom, marked patient distress. Research suggests that HSDD may arise from an imbalance of the excitatory and inhibitory neurobiological pathways that regulate the mammalian sexual response; top-down inhibition from the prefrontal cortex may be hyperactive, and/or bottom-up excitation to the limbic system may be hypoactive. Key neuromodulators for the excitatory pathways include norepinephrine, oxytocin, dopamine and melanocortins. Serotonin, opioids and endocannabinoids serve as key neuromodulators for the inhibitory pathways. Evolving treatment strategies have relied heavily on these crucial research findings, as many of the agents currently being investigated as treatment options for HSDD target and influence key players within these excitatory and inhibitory pathways, including various hormone therapies and centrally acting drugs, such as buspirone, bupropion and bremelanotide.

Treatment for hypoactive sexual desire

Flibanserin acts at cortical, limbic, hypothalamic, and brainstem nuclei to inhibit serotonin release by binding to 5-HT1A autoreceptors and block postsynaptic action of serotonin at 5-HT2A receptors. This gradually disinhibits the turnover of other monoamines like dopamine and noradrenaline that are critical for sexual desire.

Efficacy and safety of flibanserin in postmenopausal women with hypoactive sexual desire disorder: results of the SNOWDROP trial

OBJECTIVE

This study aimed to assess the efficacy and safety of flibanserin, a serotonin receptor 1A agonist/serotonin receptor 2A antagonist, in postmenopausal women with hypoactive sexual desire disorder (HSDD).

METHODS

Naturally postmenopausal women with HSDD received flibanserin 100 mg once daily at bedtime (n = 468) or placebo (n = 481) for 24 weeks. Co-primary endpoints were changes from baseline to week 24 in the number of satisfying sexual events (SSEs) across 28 days and in the Female Sexual Function Index (FSFI) desire domain score. Secondary endpoints included change from baseline in Female Sexual Distress Scale-Revised (FSDS-R) Item 13 score (which assesses distress due to low sexual desire), FSDS-R total score, and FSFI total score. The Patient Benefit Evaluation was asked on treatment discontinuation.

RESULTS

There were significant improvements with flibanserin versus placebo in the mean (SE) changes in the number of SSEs (1.0 [0.1] vs 0.6 [0.1]), FSFI desire domain score (0.7 [0.1] vs 0.4 [0.1]), FSDS-R Item 13 score (-0.8 [0.1] vs -0.6 [0.1]), FSDS-R total score (-8.3 [0.6] vs -6.3 [0.6]), and FSFI total score (4.2 [0.4] vs 2.7 [0.4]; all P < 0.01). More women on flibanserin (37.6%) than women on placebo (28.0%) reported experiencing meaningful benefits from the study medication on treatment discontinuation. The most frequent adverse events associated with flibanserin were dizziness, somnolence, nausea, and headache.

CONCLUSIONS

In naturally postmenopausal women with HSDD, flibanserin, compared with placebo, has been associated with improvement in sexual desire, improvement in the number of SSEs, and reduced distress associated with low sexual desire, and is well tolerated.

Mechanism of action of flibanserin, a multifunctional serotonin agonist and antagonist (MSAA), in hypoactive sexual desire disorder

Flibanserin is a novel multifunctional serotonin agonist and antagonist (MSAA) that improves sexual functioning in premenopausal women who suffer from reduced sexual interest and desire.

The evolving sexual health paradigm: transforming definitions into sexual health practices

Sexual health is an evolving paradigm that integrates a positive approach to sexuality with existing public health policy and practice for reducing the burdens of sexually transmitted infections, including those due to HIV. The sexual health paradigm rests in commitment to sexual rights, sexual knowledge, sexual choice, and sexual pleasure, as well as key elements of sexuality addressed by sexual desire, sexual arousal, and sexual function, and sexual behaviors. The sexual health paradigm offers new approaches to supporting general health and well being while reducing the burdens of sexual diseases and their consequences.

Efficacy of flibanserin in women with hypoactive sexual desire disorder: results from the BEGONIA trial

INTRODUCTION

Hypoactive Sexual Desire Disorder (HSDD) is characterized by low sexual desire that causes marked distress or interpersonal difficulty.

AIM

The aim of this study was to assess the efficacy and safety of the 5-HT1A agonist/5-HT2A antagonist flibanserin in premenopausal women with HSDD.

METHODS

This was a randomized, placebo-controlled trial in which premenopausal women with HSDD (mean age: 36.6 years) were treated with flibanserin 100 mg once daily at bedtime (qhs) (n = 542) or placebo (n = 545) for 24 weeks.

MAIN OUTCOME MEASURES

Coprimary end points were the change from baseline to study end in Female Sexual Function Index (FSFI) desire domain score and in number of satisfying sexual events (SSE) over 28 days. Secondary end points included the change from baseline in FSFI total score, Female Sexual Distress Scale-Revised (FSDS-R) total score, and FSDS-R Item 13 score.

RESULTS

Compared with placebo, flibanserin led to increases in mean (standard deviation) SSE of 2.5 (4.6) vs. 1.5 (4.5), mean (standard error [SE]) FSFI desire domain score of 1.0 (0.1) vs. 0.7 (0.1), and mean (SE) FSFI total score of 5.3 (0.3) vs. 3.5 (0.3); and decreases in mean (SE) FSDS-R Item 13 score of -1.0 (0.1) vs. -0.7 (0.1) and mean (SE) FSDS-R total score of -9.4 (0.6) vs. -6.1 (0.6); all P ≤ 0.0001. The most frequently reported adverse events in the flibanserin group were somnolence, dizziness, and nausea, with adverse events leading to discontinuation in 9.6% of women receiving flibanserin vs. 3.7% on placebo.

CONCLUSION

In premenopausal women with HSDD, flibanserin 100 mg qhs resulted in significant improvements in the number of SSE and sexual desire (FSFI desire domain score) vs. placebo. Flibanserin was associated with significant reductions in distress associated with sexual dysfunction (FSDS-R total score) and distress associated with low sexual desire (FSDS-R Item 13) vs. placebo. There were no significant safety concerns associated with the use of flibanserin for 24 weeks.

Motivated behaviors and levels of 3α,5α-THP in the midbrain are attenuated by knocking down expression of pregnane xenobiotic receptor in the midbrain ventral tegmental area of proestrous rats

INTRODUCTION

Progesterone (P4 ) and its product, 5α-pregnan-3α-ol-20-one (3α,5α-THP), act in the midbrain ventral tegmental area (VTA) to alter motivated behaviors, such as mating, and motor and anxiety behavior. Of interest is whether 3α,5α-THP formation requires the pregnane xenobiotic receptor (PXR), which is expressed in the midbrain of rats.

AIM

The role of PXR in the midbrain for 3α,5α-THP formation, which precedes modulation of motivated behaviors, was investigated.

METHODS

Rats had estrous cycle phase determined and were assessed when they were in diestrus or proestrus. Diestrous and proestrous rats were infused with control or antisense oligodeoxyribonucleotides (AS-ODNs) targeted against PXR to the VTA.

MAIN OUTCOME MEASURES

In pilot studies, PXR gene and protein expression in the midbrain were determined with quantitative reverse transcriptase polymerase chain reaction and Western blotting, respectively. Diestrous and proestrous rats infused with control or AS-ODNs to the VTA were tested for anxiety (open field and plus maze), social (social interaction), and sexual (paced mating) behavior. Expression of PXR in the midbrain was verified with Western blotting. Plasma estradiol, P4 , dihydroprogesterone (DHP), and 3α,5α-THP levels, and brain P4 , DHP, and 3α,5α-THP levels were measured. We predicted that proestrous rats infused with PXR AS-ODNs would have decreased anti-anxiety, social, and sexual behavior, lower midbrain expression of PXR, and lower midbrain levels of 3α,5α-THP compared with controls.

RESULTS

Results supported the hypothesis that formation of 3α,5α-THP requires PXR and may be important for motivated behaviors. PXR AS-ODN, compared with control, infusions to the VTA reduced PXR expression and 3α,5α-THP levels in the midbrain and attenuated sexual receptivity of proestrous rats.

CONCLUSIONS

Knockdown of PXR in the midbrain reduces 3α,5α-THP levels and sexual receptivity of proestrous rats. Thus, PXR in the midbrain may be required for the observed increase in 3α-5α-THP during proestrus, which has subsequent effects on motivated, reproductive behaviors.