Effect of flibanserin on libido in women with breast cancer on adjuvant endocrine therapy

12015 Background: Breast cancer and its treatment can cause decreased libido. This study evaluates the use of Flibanserin in women with breast cancer on endocrine therapy who are experiencing decreased libido. It is the first study evaluating Flibanserin for medically induced decreased libido. Methods: 37 women (mean age of 49) with stage 0-III ER+ breast cancer on endocrine therapy for at least three months were enrolled on a longitudinal IRB-approved trial from both an academic center and an alliance community site. All patients met criteria for the diagnosis of HSDD as defined by the DSM-IV and ISSWSH consensus paper. Patients took Flibanserin 100mg at bedtime for 24 weeks and were followed for 52 weeks. Patients were monitored closely with medical exams and questionnaires at baseline, weeks 4, 8, 16, 24 and 52. Feasibility and efficacy of Flibanserin was measured by patient reported validated instruments such as Female Sexual Function Index (FSFI), Pittsburg Sleep Quality Index (PSQI), PROMIS, and EQ5D. Results: A statistically significant improvement in the sexual domains of desire, arousal, lubrication, orgasm, satisfaction, and pain were seen as measured by the FSFI while on Flibanserin, which declined after discontinuing the medication. At baseline, patients had an average libido of 1.7, which increased to 2.8 at 24 weeks and declined to 2.5 after discontinuing treatment. Sexual confidence and satisfaction at baseline were an average of 1.2 and 1.6 respectively and increased to an average of 2.5 and 2.6 after treatment. Ability to become lubricated was 1.3 at baseline and increased to 4.4 at 24 weeks. Ability to maintain lubrication and ease of lubrication both averaged 1.6 at baseline and increased to 3.4 at week 24. Ease and frequency of climax scored an average 1.4 at baseline, then increased to 2.6 and 2.9 respectively at week 24. Patients reported less pain and distress with sexual intercourse throughout the study and an increased number of sexually satisfying events. At baseline, the average score for overall state of health was 78/100. At 24 weeks, the average score increased to 93 and declined to 82 at week 52 (after medication was discontinued). Patients slept an average of 6.7 hours per night at baseline, which increased to 7.7 hours on Flibanserin and decreased to 5.5 hours after discontinuing the medication. Conclusions: Our study found statistically significant improvement in the sexual domains of desire, arousal, lubrication, orgasm, satisfaction, and pain as measured by the FSFI from baseline to week 24 while on Flibanserin. It also showed improved overall health-related quality of life and sleep. Flibanserin is an effective treatment option for women with breast cancer. A larger randomized placebo-controlled study is still needed to further evaluate Flibanserin in women with breast cancer and medically induced decreased libido. Clinical trial information: NCT03707340 .