LEMTRADA induces persistent thyroid disorders see Warnings and Precautions (5.8). Untreated hypothyroidism in pregnant women increases the risk of miscarriage and may have effects on the fetus including mental retardation and dwarfism. In mothers with Graves’ disease, maternal thyroid stimulating hormone receptor antibodies can be transferred to a developing fetus and can cause neonatal Graves’ disease. In a patient who developed Graves’ disease after treatment with alemtuzumab, placental transfer of anti-thyrotropin receptor antibodies resulted in neonatal Graves’ disease with thyroid storm in her infant who was born 1 year after
alemtuzumab dosing.^L43397

When LEMTRADA was administered to pregnant huCD52 transgenic mice during organogenesis (gestation days GD 6-10 or GD 11-15) at doses of 3 or 10 mg/kg IV, no teratogenic effects were observed. However, there was an increase in embryo lethality (increased
postimplantation loss and the number of dams with all fetuses dead or resorbed) in pregnant animals dosed during GD 11-15. In a separate study in pregnant huCD52 transgenic mice, administration of LEMTRADA during organogenesis (GD 6-10 or GD 11-15) at doses of 3 or 10 mg/kg IV, decreases in B- and T-lymphocyte populations were observed in the offspring at both doses tested.^L43397

In pregnant huCD52 transgenic mice administered LEMTRADA at doses of 3 or 10 mg/kg/day IV throughout gestation and lactation, there was an increase in pup deaths during the lactation period at 10 mg/kg. Decreases in T- and B-lymphocyte populations and in antibody response were observed in offspring at both doses tested.^L43397

Before initiation of LEMTRADA treatment, women of childbearing potential should be counseled on the potential for serious risk to the fetus. To avoid in-utero exposure to LEMTRADA, women of childbearing potential should use effective contraceptive measures
when receiving a course of treatment with LEMTRADA and for 4 months following that course of treatment.^L43397

In huCD52 transgenic mice, administration of LEMTRADA prior to and during the mating period resulted in adverse effects on sperm parameters in males and a reduced number of corpora lutea and implantations in females.^L43397

Two MS patients experienced serious reactions (headache, rash, and either hypotension or sinus tachycardia) after a single accidental infusion of up to 60 mg of LEMTRADA. Doses of LEMTRADA greater than those recommended may increase the intensity and/or duration of infusion reactions or their immune effects. There is no known antidote for alemtuzumab overdosage.^L43397