Myovant Sciences and Pfizer Announce FDA Acceptance of Supplemental New Drug Application for MYFEMBREE®

Myovant Sciences (NYSE: MYOV) and Pfizer Inc. (NYSE: PFE) announced today that the U.S. Food and Drug Administration (FDA) accepted for review a supplemental New Drug Application (sNDA) for MYFEMBREE® (relugolix 40 mg, estradiol 1 mg, and norethindrone acetate 0.5 mg). The sNDA proposes updates to MYFEMBREE’s United States Prescribing Information (USPI) based on safety and efficacy data from the Phase 3 LIBERTY randomized withdrawal study (RWS) of MYFEMBREE in premenopausal women with heavy menstrual bleeding associated with uterine fibroids for up to two years. The FDA set a target action date of January 29, 2023 for this sNDA under the Prescription Drug User Fee Act (PDUFA).

“Heavy menstrual bleeding is the most common symptom affecting women with uterine fibroids that can impact their daily life and activities over a long period of time,” said Juan Camilo Arjona Ferreira, M.D., Chief Medical Officer of Myovant Sciences, Inc. “We are pleased to submit these study results to the FDA as they show the value MYFEMBREE can potentially have on treating women’s uterine fibroid symptoms long term.”

Patients who completed the 24-week pivotal LIBERTY 1 and 2 studies were offered the option to receive MYFEMBREE for an additional 28 weeks in an open-label extension study. After completion of the LIBERTY 1 or LIBERTY 2 and the open-label extension studies, women who met the definition of responder (menstrual blood loss < 80 mL and a reduction from pivotal study baseline > 50%) could participate in an additional 52-week randomized withdrawal study (N=229) designed to provide two-year safety and efficacy data on MYFEMBREE and to evaluate the need for maintenance therapy.  Women who entered the RWS were re-randomized to either MYFEMBREE or placebo for 52 additional weeks (N = 229), with the primary endpoint at Week 76. The LIBERTY randomized withdrawal study met its primary endpoint with 78.4% of women who continued on MYFEMBREE achieving the sustained responder rate (menstrual blood loss < 80 mL) through Week 76 compared with 15.1% of women who discontinued treatment and initiated placebo at Week 52 (p < 0.0001). All three key secondary endpoints in the LIBERTY randomized withdrawal study were also achieved, including sustained responder rate through Week 104, time to relapse of heavy menstrual bleeding, and amenorrhea rate (all p < 0.0001). 

About Uterine Fibroids
Uterine fibroids are noncancerous tumors that develop in or on the muscular walls of the uterus and are among the most common reproductive tract tumors in women. In addition to an individual’s genetic predisposition, estrogens are well known to play an important role in the regulation of fibroid growth.

Although uterine fibroids are benign tumors, they can cause debilitating symptoms such as heavy menstrual bleeding (frequently resulting in anemia and fatigue), pain (including painful periods, abdominal pain, painful intercourse, backache), increased abdominal girth and bloating, urinary frequency or retention, constipation, pregnancy loss, and, in some cases, infertility. These symptoms can also lead to loss of productivity at work, limitations in normal activities of daily living, and social embarrassment.

An estimated five million women in the U.S. suffer from symptoms of uterine fibroids,i and an estimated three million women are inadequately treated by current medical therapy.ii

MYFEMBREE (relugolix, estradiol, and norethindrone acetate) is the first and only once-daily oral treatment for heavy menstrual bleeding associated with uterine fibroids in premenopausal women approved by the U.S. Food and Drug Administration, with a treatment duration of up to 24 months. 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.

About Myovant Sciences 
Myovant Sciences aspires to redefine care for women and for men through purpose-driven science, empowering medicines, and transformative advocacy. Founded in 2016, Myovant has executed five successful Phase 3 clinical trials across oncology and women’s health leading to two regulatory approvals by the U.S. Food and Drug Administration (FDA) for men with advanced prostate cancer and women with heavy menstrual bleeding associated with uterine fibroids, respectively. Myovant also has received regulatory approvals by the European Commission (EC) for women with symptomatic uterine fibroids and for men with advanced hormone-sensitive prostate cancer. Myovant has supplemental New Drug Applications under review with the FDA for endometriosis-associated pain, and for updates to the United States Prescribing Information (USPI) based on safety and efficacy data from the Phase 3 LIBERTY randomized withdrawal study (RWS) of MYFEMBREE in premenopausal women with heavy menstrual bleeding due to uterine fibroids for up to two years. Myovant also is conducting a Phase 3 study to evaluate the prevention of pregnancy in women with uterine fibroids or endometriosis. Myovant also is developing MVT-602, an investigational oligopeptide kisspeptin-1 receptor agonist, which has completed a Phase 2a study for female infertility as part of assisted reproduction.

About Pfizer: Breakthroughs That Change Patients’ Lives
At Pfizer, we apply science and our global resources to bring therapies to people that extend and significantly improve their lives. We strive to set the standard for quality, safety and value in the discovery, development and manufacture of health care products, including innovative medicines and vaccines. Every day, Pfizer colleagues work across developed and emerging markets to advance wellness, prevention, treatments and cures that challenge the most feared diseases of our time. Consistent with our responsibility as one of the world’s premier innovative biopharmaceutical companies, we collaborate with health care providers, governments and local communities to support and expand access to reliable, affordable health care around the world. For more than 170 years, we have worked to make a difference for all who rely on us.