A new drug class to treat uterine fibroids
Relugolix is one of three GnRH antagonists being studied for the long-term treatment of fibroids. The Food and Drug Administration approved the combination of elagolix, estradiol, and norethindrone acetate (Oriahnn) in May. Linzagolix, another GnRH antagonist, is currently in clinical trials.
“We’ll have a whole class of new drugs that are likely to fulfill this long sought-after goal of reducing the need for surgery for fibroids and doing it without a lot of side effects,” Dr. Taylor said. “The quality-of-life improvements seen here, the lack of significant adverse effects – none that were surprising in long term – the relatively low reduction in bone mineral density in a year are all very exciting [and suggest] that this will be a safe and effective long-term treatment.”
Significant improvement in quality of life
In the presentation on quality of life with relugolix therapy, Dr. Al-Hendy shared results regarding the severity of women’s symptoms as well as health-related quality of life, as determined on the basis of the Uterine Fibroid Symptom and Health-Related Quality of Life (UFS-QoL) questionnaire at baseline, week 12, and week 24 in LIBERTY 1 and 2. Higher UFS-QoL scores correlate with more severe symptoms. With the subscale of health-related quality of life, higher scores indicate a better quality of life.
The substudy enrolled 253 patients who received relugolix combination therapy and 256 patients who received placebo. The average menstrual blood loss was 243 mL in the relugolix group and 215 mL in the placebo group at baseline. Mean fibroid volume was the same in both groups at baseline, 73 cm3.
The proportion of Black patients was similar in both groups: 48% of the relugolix group and 54% of the placebo group.
The severity of women’s symptoms dropped from a baseline UFS-QoL score of 57 to 22.4 at 6 months among those who received relugolix combination therapy. In the placebo group, the initial score of 59.6 only dropped to 46.9 (P < .0001, for –21.4 difference in change).
Health-related quality of life increased from 38.3 to 76.6 among those who received relugolix. In the placebo group, it increased from 35.7 to 48.2 (P < .0001, for 24.5 difference). Subscales of health-related quality of life – including concern, control, activities, energy/mood, self-consciousness, and sexual function – also all improved significantly in the relugolix group, compared with the placebo group (P < .0001).
“This is a condition we see all the time that’s easily diagnosed, and we have first-line drugs we’ve been using to treat them, but none are good long-term fixes,” Dr. Taylor said. The current first-line treatments, oral contraceptives, can stabilize bleeding, “but they don’t make the fibroids shrink, they don’t stop the bleeding, women continue to have breakthrough bleeding, and the fibroids can continue to grow.”
He said most of the estimated 600,000 hysterectomies performed in the United States each year are for uterine fibroids.
“It’s a major surgery that no one wants to go through if they don’t have to,” Dr. Taylor said. “Here we have a drug that really has potential to stop the growth of the fibroids, that can stop the bleeding or dramatically improve it, and, really, for the first time, directly impact the fibroids and give us a long-term alternative.”
The studies were funded by Myovant Sciences. Dr. Al-Hendy reported consulting for AbbVie, Bayer, and Myovant Sciences, and he owns a patent for novel diagnostics and therapeutics for uterine sarcoma. Dr. Taylor has disclosed no relevant financial relationships.
A version of this article originally appeared on Medscape.com.