8.1Pregnancy Risk Summary Based
on findings from animal reproduction studies, miglustat may cause fetal harm when administered to a pregnant woman. Available data from postmarketing case reports with miglustat use in pregnancy are insufficient to assess a drug-associated risk of major birth defects, miscarriage, or adverse maternal or fetal outcomes. There are risks associated with symptomatic Type I Gaucher disease in pregnancy, including hepatosplenomegaly and thrombocytopenia (see Clinical Considerations ).
Advise pregnant women of the potential risks to the fetus. In animal reproduction studies, miglustat was maternally toxic in rabbits at exposures near the expected human therapeutic dose and caused embryo-fetal toxicities in rats at doses twice the recommended human dose. No adverse developmental outcomes were observed with administration of miglustat to pregnant rats at dose levels 6 times the recommended human dose.
(see Data ). The estimated background risk of major birth defects and miscarriage for the indicated population is unknown. All pregnancies have a background risk of birth defect, loss, or other adverse outcomes. In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2–4% and 15–20%, respectively. Clinical Considerations Disease-associated Maternal and Embryo-Fetal Risk Pregnancy may exacerbate existing Type 1 Gaucher disease symptoms or result in new disease manifestations.
Type 1 Gaucher disease manifestations may lead to adverse pregnancy outcomes including, hepatosplenomegaly which can interfere with the normal growth of a pregnancy and thrombocytopenia which can lead to increased bleeding and possible hemorrhage. Data Animal Data In female rats given miglustat by oral gavage at doses of 20, 60, 180 mg/kg/day beginning 14 days before mating and continuing through gestation day 17 (organogenesis), increased post implantation loss, decreased embryo-fetal survival and decreased fetal and pup weights were observed at doses ≥60 mg/kg/day (≥2 times the human therapeutic dose on a mg/m 2 basis).
Miglustat was also administered to pregnant rats by oral gavage at doses of 20, 60, 180 mg/kg/day from gestation day 6 through lactation (postpartum day 20). Delayed and prolonged parturition with decreased live births were observed at doses ≥60 mg/kg/day (≥2 times the human therapeutic dose on a mg/m 2 basis). In pregnant rabbits given miglustat by oral gavage at doses of 15, 30, 45 mg/kg/day during gestation days 6–18 (organogenesis), maternal toxicity, including maternal deaths (all doses), reduced food consumption (30 and 45 mg/kg/day), and decreased body weight gain (15 and 30 mg/kg/day), was observed.
The 15 mg/kg/day dose level was 0.97 times the human therapeutic dose on a mg/m 2 basis. In a pre- and postnatal development study in rats, miglustat was administered by oral gavage at doses of 20, 60, 180 mg/kg/day from gestation day 6 through day 20 of lactation, decreased live births were observed in dams, as well as decreased body weight gain in the offspring at doses ≥60 mg/kg/day (≥2 times the human therapeutic dose on a mg/m 2 basis).
There was no effect on behavioral and learning assessments, sexual maturation or reproductive performance of the offspring at doses up to 180 mg/kg/day (about 6 times the human therapeutic dose on a mg/m 2 basis).
