Relugolix, estradiol hemihydrate, and norethindrone

Avoid use of MYFEMBREE with oral P-gp inhibitors. ( 7.1 ) Avoid use with combined P-gp and strong CYP3A inducers, as the exposure of the components of MYFEMBREE may be decreased. ( 7.1 )

7.1 Effect of Other Drugs on MYFEMBREE P-gp Inhibitors Co-administration of MYFEMBREE with P-gp inhibitors increases the AUC and maximum concentration (C max ) of relugolix [see Clinical Pharmacology ( 12.3 )] and may increase the risk of adverse reactions associated with MYFEMBREE. 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 [see Dosage and Administration ( 2.4 )] .

Combined P-gp and Strong CYP3A Inducers Use of MYFEMBREE with combined P-gp and strong CYP3A inducers decreases the AUC and C max of relugolix, estradiol, and/or norethindrone [see Clinical Pharmacology ( 12.3 )] and may decrease the therapeutic effects of MYFEMBREE. Avoid use of MYFEMBREE with combined P-gp and strong CYP3A inducers.

8.1 Pregnancy Pregnancy Exposure Registry There is a pregnancy exposure registry that monitors pregnancy outcomes in women exposed to MYFEMBREE during pregnancy. Pregnant females exposed to MYFEMBREE and healthcare providers are encouraged to call the MYFEMBREE Pregnancy Exposure Registry at 1-855-428-0707. Risk Summary MYFEMBREE is contraindicated in pregnancy [see Contraindications ( 4 ) and Warnings and Precautions ( 5.9 )]. Based on findings from animal studies and its mechanism of action, MYFEMBREE may cause early pregnancy loss. Discontinue MYFEMBREE if pregnancy occurs during treatment [see Warnings and Precautions ( 5.9 ) and Clinical Pharmacology ( 12.1 )] .

The limited human data with the use of MYFEMBREE in pregnant women are insufficient to evaluate for a drug-associated risk of major birth defects, miscarriage, or adverse maternal or fetal outcomes [see Data ]. In animal reproduction studies, oral administration of relugolix in pregnant rabbits during organogenesis resulted in spontaneous abortion and total litter loss at relugolix exposures about half those at the maximum recommended human dose (MRHD) of 40 mg. In both rabbits and rats, no fetal malformations were present at any dose level tested which were associated with relugolix exposures about half and approximately 300 times exposures in women at the MRHD, respectively [see Data ].

Epidemiologic studies and meta-analyses have not found an increased risk of genital or non-genital birth defects (including cardiac anomalies and limb-reduction defects) following exposure to estrogens and progestins before conception or during early pregnancy. The estimated background risk of major birth defects and miscarriage for the indicated population is unknown. There are insufficient data to conclude whether the presence of uterine fibroids or endometriosis reduces the likelihood of achieving pregnancy or increases the risk of adverse pregnancy outcomes. All pregnancies have a background risk of birth defect, loss, or other adverse outcomes.

In the United States general population, the estimated background risks of major birth defects and miscarriage in clinically recognized pregnancies are 2% to 4% and 15% to 20%, respectively. Data Animal Data In an embryo-fetal development study, oral administration of relugolix to pregnant rabbits during the period of organogenesis (Days 6 to 18 of gestation) resulted in abortion, total litter loss, or decreased number of live fetuses at a dose of 9 mg/kg/day (about half the human exposure at the maximum recommended human dose [MRHD] of 40 mg daily, based on…