(017) FLIBANSERIN IMPROVES LIBIDO AND SEXUAL SATISFACTION IN WOMEN WITH BREAST CANCER ON ENDOCRINE THERAPY
Authors: Goldfarb S , Carter J , Toumbacaris N , Cheng M , Arkema A , Abdo N , Chang C , Wong S , Jamner A , Chen Y , Vahdat L 
Published: June 2024

Abstract

Introduction
Decreased libido is a distressful symptom during and after cancer treatment. This is the first prospective longitudinal study that investigates the use of flibanserin to treat decreased libido in breast cancer patients on endocrine therapy.

Objective
This study evaluates the efficacy of flibanserin as measured by change in desire, sexual function, and distress from sexual dysfunction. These outcomes are measured using the following validated instruments: Female Sexual Function Index (FSFI) both desire and total scores, Patient-reported Outcomes Measurement Information System Sexual Function Instrument (PROMIS-SF) and patient distress via FSDS-R.

Methods
Forty-three women with stage 0-III ER+ breast cancer on endocrine therapy for at least 3 months who reported HSDD as defined by the DSM-IV and ISSWH consensus paper were enrolled on an IRB-approved prospective, longitudinal trial from both an academic center and an alliance community site. All patients took flibanserin 100mg nightly for 24 to 36 weeks. Patients were monitored closely for 52 weeks for adverse events, with medical exams and questionnaires at baseline, week 4, 8, 16, 24, 52 with optional week 36 appointments. Given the small sample size, descriptive, graphical, and nonparametric paired tests for pairwise comparisons of a measure were performed.

Results
Participants reported improved libido and sexual satisfaction as demonstrated by both the PROMIS-SF and FSFI data (see Table 1). 35/43 (83.3%) patients completed the FSFI and 25/43 (58.1%) completed the PROMIS-SF. The mean overall total FSFI score increased from 11 at baseline, to 17 at week 8 and 24 at week 36. The PROMIS data for interest in sexual activity improved from a baseline mean score of 43 to 51 at 8 weeks, to 54 at 24 weeks and 55 at 36 weeks. Similarly, the FSFI data in the domains of desire and arousal improved respectively from 1.90 and 1.56 at baseline to 3.03 and 3.05 at 8 weeks, 3.30 and 3.17 at week 16 and 3.53 and 4.01 at week 36. Satisfaction with sex life also improved from PROMIS baseline of 46 to 49 at week 8 and 55 at week 36. FSFI data for the domain of satisfaction indicate parallel trends with a baseline score of 2.36, increasing to 3.15 at week 8 and 4.45 at week 36. Furthermore, vaginal discomfort scores improved on both the PROMIS and FSFI. FSFI data on lubrication also showed improvement with a baseline mean score of 1.85 increasing to 2.84 by week 8, 3.24 at week 24 and 4.01 at week 36. However, the PROMIS suggests a decrease in lubrication from baseline to week 8. Patient distress also decreased throughout the study as measured on the FSDS-R and distress thermometer. There were no severe adverse events. The most common adverse events were nausea, somnolence and dizziness.

Conclusions
Flibanserin improves libido and overall sexual function as measured by the PROMIS-SF and FSFI in breast cancer patients on endocrine therapy. The exciting data from this pilot study is currently informing a larger randomized placebo-controlled study evaluating the efficacy of flibanserin in women with breast cancer.

Disclosure
Yes, this is sponsored by industry/sponsor: Sprout Pharmaceuticals
Clarification: Industry funding only - investigator initiated and executed study
Any of the authors act as a consultant, employee or shareholder of an industry for: Ms. Medicine, NanOlogy LLC, Paxman Cooling Ltd, Procter and Gamble, Rejoy, Revision Skincare, Sermonix, Shook, Hardy and Bacon, Spectrum Pharmaceuticals, Sprout Pharmaceuticals, TerSera.