] (GLOBE NEWSWIRE) -- 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 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
Bone mineral density remained stable in women who received MYFEMBREE in the randomized withdrawal study. Additionally, bone mineral density was maintained through two years in the subset of women continuously treated with MYFEMBREE (N = 31). The incidence of adverse events over one additional year of treatment was consistent with those observed in prior studies, with no new safety signals observed.
"Data from the MYFEMBREE RWS supports our mission to improve care for women living with uterine fibroids," said James Rusnak, M.D., Ph.D., Senior Vice President, Chief Development Officer, Internal Medicine and Hospital, Global Product Development at Pfizer. "We look forward to the FDA's review of the application and potential updates to the MYFEMBREE prescribing information based on these data."
MYFEMBREE was approved in the U.S. in 2021 for the management of heavy menstrual bleeding associated with uterine fibroids in premenopausal women with a treatment duration of up to 24 months.
About the Phase 3 LIBERTY Program in Uterine Fibroids
The Phase 3 clinical program for uterine fibroids consisted of two multi-national, replicate pivotal clinical studies (LIBERTY 1, N=388 and LIBERTY 2, N=382) of MYFEMBREE® in women with heavy menstrual bleeding associated with uterine fibroids for 24 weeks. Eligible women who completed the LIBERTY 1 or LIBERTY 2 studies were offered the opportunity to enroll in an active treatment, open-label extension study in which all women received MYFEMBREE for an additional 28-week period for a total treatment period of 52 weeks (N=477), designed to evaluate the safety and efficacy of longer-term treatment. After completion of the LIBERTY 1 or LIBERTY 2 and open-label extension studies, eligible women could elect to 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. Across the LIBERTY 1, LIBERTY 2 and open-label extension studies, a response was defined as a menstrual blood loss volume of less than 80 mL and a 50% or greater reduction from baseline in menstrual blood loss volume during the last 35 days of treatment measured using the alkaline hematin method.
LIBERTY 1 and LIBERTY 2 met their primary endpoints (p
In the open-label extension study, changes in bone mineral density through one year, as assessed by DXA every three months, were consistent with LIBERTY 1 and 2. The incidence of adverse events over one year was consistent with that observed in LIBERTY 1 and 2, with no new safety signals observed.
The LIBERTY randomized withdrawal study met its primary endpoint of maintaining sustained responder rate (menstrual blood loss
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
About MYFEMBREE®
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.
For full prescribing information including Boxed Warning and patient information, click here.
Indications and Usage
MYFEMBREE is indicated for the management of heavy menstrual bleeding associated with uterine leiomyomas (fibroids) in premenopausal women. Limitations of Use: Use of MYFEMBREE should be limited to 24 months due to the risk of continued bone loss which may not be reversible.
Important Safety Information
BOXED WARNING: THROMBOEMBOLIC DISORDERS AND VASCULAR EVENTS
Estrogen and progestin combination products, including MYFEMBREE, increase the risk of thrombotic or thromboembolic disorders including pulmonary embolism, deep vein thrombosis, stroke and myocardial infarction, especially in women at increased risk for these events.
MYFEMBREE is contraindicated in women with current or a history of thrombotic or thromboembolic disorders and in women at increased risk for these events, including women over 35 years of age who smoke or women with uncontrolled hypertension.
CONTRAINDICATIONS
MYFEMBREE is contraindicated in women with any of the following: high risk of arterial, venous thrombotic, or thromboembolic disorder; pregnancy; known osteoporosis; current or history of breast cancer or other hormone-sensitive malignancies; known hepatic impairment or disease; undiagnosed abnormal uterine bleeding; known hypersensitivity to components of MYFEMBREE.
WARNINGS AND PRECAUTIONS
Thromboembolic Disorders: Discontinue immediately if an arterial or venous thrombotic, cardiovascular, or cerebrovascular event occurs or is suspected. Discontinue at least 4 to 6 weeks before surgery associated with an increased risk of thromboembolism, or during periods of prolonged immobilization, if feasible. Discontinue immediately if there is sudden unexplained partial or complete loss of vision, proptosis, diplopia, papilledema, or retinal vascular lesions and evaluate for retinal vein thrombosis as these have been reported with estrogens and progestins.
Bone Loss: MYFEMBREE may cause a decrease in bone mineral density (BMD) in some patients, which may be greater with increasing duration of use and may not be completely reversible after stopping treatment. Consider the benefits and risks in patients with a history of low trauma fracture or risk factors for osteoporosis or bone loss, including medications that may decrease BMD. Assessment of BMD by dual-energy X-ray absorptiometry (DXA) is recommended at baseline and periodically thereafter. Consider discontinuing MYFEMBREE if the risk of bone loss exceeds the potential benefit.
Hormone-Sensitive Malignancies: Discontinue MYFEMBREE if a hormone-sensitive malignancy is diagnosed. Surveillance measures in accordance with standard of care, such as breast examinations and mammography are recommended. Use of estrogen alone or estrogen plus progestin has resulted in abnormal mammograms requiring further evaluation.
Depression, Mood Disorders, and Suicidal Ideation: Promptly evaluate patients with mood changes and depressive symptoms including shortly after initiating treatment, to determine whether the risks of continued therapy outweigh the benefits. Patients with new or worsening depression, anxiety, or other mood changes should be referred to a mental health professional, as appropriate. Advise patients to seek immediate medical attention for suicidal ideation and behavior and reevaluate the benefits and risks of continuing MYFEMBREE.
Hepatic Impairment and Transaminase Elevations: Steroid hormones may be poorly metabolized in these patients. Instruct women to promptly seek medical attention for symptoms or signs that may reflect liver injury, such as jaundice or right upper abdominal pain. Acute liver test abnormalities may necessitate the discontinuation of MYFEMBREE use until the liver tests return to normal and MYFEMBREE causation has been excluded.
Gallbladder Disease or History of Cholestatic Jaundice: Discontinue MYFEMBREE if signs or symptoms of gallbladder disease or jaundice occur. For women with a history of cholestatic jaundice associated with past estrogen use or with pregnancy, assess the risk-benefit of continuing therapy. Studies among estrogen users suggest a small increased relative risk of developing gallbladder disease.
Elevated Blood Pressure: For women with well-controlled hypertension, monitor blood pressure and stop MYFEMBREE if blood pressure rises significantly.
Change in Menstrual Bleeding Pattern and Reduced Ability to Recognize Pregnancy: Advise women to use non-hormonal contraception during treatment and for one week after discontinuing MYFEMBREE. Avoid concomitant use of hormonal contraceptives. MYFEMBREE may delay the ability to recognize pregnancy because it alters menstrual bleeding. Perform testing if pregnancy is suspected and discontinue MYFEMBREE if pregnancy is confirmed.
Risk of Early Pregnancy Loss: MYFEMBREE can cause early pregnancy loss. Exclude pregnancy before initiating and advise women to use effective non-hormonal contraception.
Uterine Fibroid Prolapse or Expulsion: Advise women with known or suspected submucosal uterine fibroids about the possibility of uterine fibroid prolapse or expulsion and instruct them to contact their physician if severe bleeding and/or cramping occurs.
Alopecia: Alopecia, hair loss, and hair thinning were reported in phase 3 trials with MYFEMBREE. Consider discontinuing MYFEMBREE if hair loss becomes a concern. Whether the hair loss is reversible is unknown.
Effects on Carbohydrate and Lipid Metabolism: More frequent monitoring in MYFEMBREE-treated women with prediabetes and diabetes may be necessary. MYFEMBREE may decrease glucose tolerance and result in increased blood glucose concentrations. Monitor lipid levels and consider discontinuing if hypercholesterolemia or hypertriglyceridemia worsens. In women with pre-existing hypertriglyceridemia, estrogen therapy may be associated with elevations in triglycerides levels leading to pancreatitis. Use of MYFEMBREE is associated with increases in total cholesterol and LDL-C.
Effect on Other Laboratory Results: Patients with hypothyroidism and hypoadrenalism may require higher doses of thyroid hormone or cortisol replacement therapy. Use of estrogen and progestin combinations may raise serum concentrations of binding proteins (e.g., thyroid-binding globulin, corticosteroid-binding globulin), which may reduce free thyroid or corticosteroid hormone levels. Use of estrogen and progestin may also affect the levels of sex hormone-binding globulin, and coagulation factors.
Hypersensitivity Reactions: Immediately discontinue MYFEMBREE if a hypersensitivity reaction occurs.
ADVERSE REACTIONS
Most common adverse reactions for MYFEMBREE (incidence ≥3% and greater than placebo) were hot flush/hyperhidrosis/night sweats, abnormal uterine bleeding, alopecia, and decreased libido. These are not all the possible side effects of MYFEMBREE.
DRUG INTERACTIONS
P-gp Inhibitors: Avoid use of MYFEMBREE with oral P-gp inhibitors. If use is unavoidable, take MYFEMBREE first, separate dosing by at least 6 hours, and monitor patients for adverse reactions.
Combined P-gp and Strong CYP3A Inducers: Avoid use of MYFEMBREE with combined P-gp and strong CYP3A inducers.
LACTATION
Advise women not to breastfeed while taking MYFEMBREE.
About Myovant Sciences
