FDA Extends Review of sNDA for Myfembree

The FDA has extended the review of the supplemental new drug application (sNDA) for Myfembree (relugolix, estradiol, and norethindrone acetate) for the management of moderate-to-severe pain associated with endometriosis. Regulators want additional time to review information they had requested from the companies regarding bone mineral density. The extended Prescription Drug User Fee Act (PDUFA) goal date is August 6, 2022.

Developed by Myovant Sciences and Pfizer, Myfembree was approved in the United States in May 2021 for the management of heavy menstrual bleeding associated with uterine fibroids in premenopausal women. Data to support this indication was based on the phase 3 LIBERTY 1 and LIBERTY 2 trials, which were published in the New England Journal of Medicine.

In April 2022, regulators had notified the companies that there were deficiencies in the application for endometriosis indication.

Juan Camilo Arjona Ferreira, M.D.

“We remain confident in the clinical profile of Myfembree and its potential to become a therapeutic option for the management of endometriosis-associated pain,” Juan Camilo Arjona Ferreira, M.D., chief medical officer of Myovant Sciences, said in a press release. “We will continue to work closely with the FDA to support the ongoing review of the sNDA.”

The sNDA was based on data from the phase 3 SPIRIT program, which included two multinational clinical studies (SPIRIT 1 and SPIRIT 2) in more than 1,200 women with pain associated with endometriosis for 24 weeks, and an open-label extension study for eligible women who completed either SPIRIT 1 or SPIRIT 2 through one year.

Myfembree contains relugolix, which reduces the amount of estrogen (and other hormones) produced by ovaries, estradiol (an estrogen) which may reduce the risk of bone loss, and norethindrone acetate (a progestin) which is necessary when women with a uterus (womb) take estrogen.