The FDA approved the use of relugolix 40 mg, estradiol 1 mg, and norethindrone acetate 0.5 mg) (Myfembree) for an additional indication: moderate to severe endometriosis pain in premenopausal women for up to 24 months. The once-daily pill was originally approved in May 2022 to treat heavy menstrual bleeding linked to uterine fibroids in premenopausal women.
Data from the phase 3 SPIRIT trial showed the relugolix combination treatment reduced menstrual pain and nonmenstrual pelvic pain in premenopausal women with endometriosis, and a loss of mean bone mineral density of less than 1% from baseline through 1 year of treatment. SPIRIT 1 and 2 each met their co-primary end points, with 75% of women in the relugolix combination treatment group in both studies achieving a clinically meaningful reduction in dysmenorrhea compared with 27% and 30% of women in the placebo groups at week 24, respectively (both P<.0001). For nonmenstrual pelvic pain, treatment with relugolix combination demonstrated a clinically meaningful reduction in pain in 59% and 66% of women, compared with 40% and 43% of women in the placebo groups (P<.0001). Adverse reactions occurring in at least 3% of women treated with relugolix combination and greater than placebo were headache, vasomotor symptoms, mood disorders, abnormal uterine bleeding, nausea, toothache, back pain, decreased sexual desire and arousal, arthralgia, fatigue, and dizziness.
Annual monitoring of bone mineral density is recommended while treating women with endometriosis.
For full prescribing information, including a Boxed Warning, consult product labeling.
Myovant and Pfizer are co-marketing the drug and providing a MYFEMBREE Support Program to support access services, including insurance benefits checks, prior authorization support, co-pay support for commercially insured patients, and patient assistance for qualifying uninsured patients.