Benzinga | May 27, 2021 08:15AM EDT

Myovant - Pfizer's Uterine Fibroids Treatment Wins FDA Approval

* The FDA has approved Myovant Sciences Ltd (NYSE:MYOV) and Pfizer Inc's (NYSE:PFE) relugolix combined with estradiol and norethindrone acetate for heavy menstrual bleeding linked to uterine fibroids in premenopausal women.

* The once-daily treatment will be marketed as Myfembree, with a treatment duration of up to two years.

* Wednesday's approval marks the second FDA nod for Myovant in less than a year after relugolix scored a go-ahead in prostate cancer in December.

* The company is also testing its flagship drug in women with endometriosis, another painful disorder involving the uterus' tissue, and pregnancy prevention medication.

* Pfizer will help Myovant sell Myfembree for uterine fibroid patients in the U.S. as early as June.

* The FDA based its Myfembree approval on two replicate phase 3 trials, Liberty 1 and Liberty 2, that showed the med significantly beat placebo in preventing blood loss among women with uterine fibroids.

* Specifically, 72.1% and 71.2% of women in the relugolix arm responded to the treatment compared with 16.8% and 14.7% of women in the placebo groups after 24 weeks, respectively.

* In its approval, the FDA warned that the drug shouldn't be used for longer than 24 months due to the risk of continued bone loss that may not be reversible.

* Price Action: PFE shares are up 0.18% at $38.99, while MYOV shares are down 1.39% at $23.35 during the premarket session on the last check Thursday.

* Related content: Benzinga's Full FDA Calendar