New research from Memorial Sloan Kettering Cancer Center (MSK) led by medical oncologist Shari Goldfarb, MD, and colleagues, reports positive findings for the use of Addyi (flibanserin) tablets in breast cancer patients on endocrine therapy who are suffering from treatment- or disease- induced low libido. There are currently a lack of effective treatment options for these women suffering from Hypoactive Sexual Desire Disorder (HSDD), or loss of libido, and it is estimated that more than 16.5 million people live with and beyond cancer treatment in the United States. The findings were presented at the Annual Meeting for The International Society for the Study of Women’s Sexual Health (ISSWSH).
Dr. Shari Goldfarb, a breast medical oncologist from Memorial Sloan Kettering Cancer Center and the study’s primary investigator said, “Sexual dysfunction is one of the most common and unaddressed side effects of treatment among female cancer survivors. As investigators, we wanted to conduct a study to help treat decreased libido, which is an often distressing symptom for women on endocrine therapy. This study evaluated the impact of flibanserin on decreased libido in women with breast cancer on endocrine therapy. The early results are promising and show that this study is on track to meet its pre-defined feasibility endpoint with most study participants showing significant benefit from flibanserin.”
This ongoing study will enroll 30 women with breast cancer on endocrine therapy who are suffering from HSDD. Preliminary results from the first 20 women completing 24 weeks of flibanserin therapy show the study is on track to meet its primary feasibility end point, with >70% of women completing the 24-week treatment period and 15% discontinuing the study early due to an adverse event, all of which occurred during the first two weeks of treatment. Adverse events included dizziness, insomnia, sleepiness, and nausea. No serious adverse events occurred in the study. In addition, most women reported increased sexual desire, increased number of satisfying sexual events (SSEs) and decreased associated distress after 8 weeks of treatment.
Cindy Eckert, CEO of Sprout Pharmaceuticals said, “My heart goes out to breast cancer survivors who often struggle with their low libido. These interim results on the use of flibanserin in this population are encouraging. We are grateful to Dr. Goldfarb and Sloan Kettering for taking on this groundbreaking research and sharing it with the medical community.”
To this point, there are no FDA-approved medications for women with HSDD secondary to cancer or its treatment, and a recently published Phase II study found that bupropion was not more effective than placebo in improving sexual desire in female cancer survivors. Yet, it is estimated that 70% of women diagnosed with breast cancer report having sexual dysfunction; this includes disorders of sexual desire and sexual response. In Feb 2018, the American Society of Clinical Oncology (ASCO) published guidelines that recommend “For women with cancer who are having problems with sexual response, including desire, arousal, or orgasm, doctors should offer psychosocial and/or psychosexual counseling. For premenopausal women with HSDD, doctors may suggest flibanserin.” The guidelines also state that “the panel noted that flibanserin has not been tested in women with a history of cancer or women taking hormonal therapy, so the risk/benefit analysis of this medicine for women who’ve been diagnosed with cancer is unclear.” Dr. Goldfarb’s study findings provide new data to help close this gap in medical knowledge.
