After a bump in the road back in April, Myovant and Pfizer have won a label expansion covering Myfembree's use in endometriosis.
Previously, the FDA flagged deficiencies in the partners' drug application ahead of its original May 6 decision date. Since then, Myovant said in a July quarterly earnings release that pending the green light, the companies would roll out the drug in its new use this month.
Today, the partners can breathe a sigh of relief and move ahead with the launch. The once-a-day therapy won FDA approval to treat moderate to severe endometriosis pain in pre-menopausal women for up to 24 months.
The FDA based its approval on data from the companies’ phase 3 Spirit studies, which tested the drug in more than 1,200 women with endometriosis pain. In the trials, 75% of patients treated with Myfembree experienced a reduction in severe and frequent menstrual cramps and pain. That compared with 27% and 30% of women in the placebo groups in the two trials.
Endometriosis, which impacts approximately 190 million women globally, is a condition where tissue similar to uterine lining grows outside of the uterine cavity. It causes painful periods, fatigue, lower back and abdomen pain, heavy menstrual bleeding, and painful sexual intercourse.
Before the approval, treatment options included pain medications, oral contraceptives, progestins, surgery and more. Still, those options didn't provide relief for many women.
Myfembree won its original FDA nod last May to treat heavy menstrual bleeding linked in uterine fibroids in premenopausal women. Pfizer doled out $650 million up front in 2020 to get in on the drug. Myovant stands to collect a $100 million milestone payment upon today's approval.