Animal Data
In a rat fertility and early embryonic development study, bosutinib was administered orally to female rats for approximately 3 to 6 weeks, depending on day of mating (2 weeks prior to cohabitation with untreated breeder males until gestation day [GD] 7). Increased embryonic resorptions occurred at greater than or equal to 10 mg/kg/day of bosutinib (1.6 and 1.2 times the human exposure at the recommended doses of 400 or 500 mg/day, respectively), and decreased implantations and reduced number of viable embryos at 30 mg/kg/day of bosutinib (3.4 and 2.5 times the human exposure at the recommended doses of 400 or 500 mg/day, respectively).
In an embryo-fetal development study conducted in rabbits, bosutinib was administered orally to pregnant animals during the period of organogenesis at doses of 3, 10, and 30 mg/kg/day. At the maternally-toxic dose of 30 mg/kg/day of bosutinib, there were fetal anomalies (fused sternebrae, and 2 fetuses had various visceral observations), and an approximate 6% decrease in fetal body weight. The dose of 30 mg/kg/day resulted in exposures (AUC) approximately 5.1 and 3.8 times the human exposures at the recommended doses of 400 and 500 mg/day, respectively.
Fetal exposure to bosutinib-derived radioactivity during pregnancy was demonstrated in a placental-transfer study in pregnant rats. In a rat pre- and postnatal development study, bosutinib was administered orally to pregnant animals during the period of organogenesis through lactation day 20 at doses of 10, 30, and 70 mg/kg/day. Reduced number of pups born occurred at greater than or equal to 30 mg/kg/day bosutinib (3.4 and 2.5 times the human exposure at the recommended doses of 400 or 500 mg/day, respectively), and increased incidence of total litter loss and decreased growth of offspring after birth occurred at 70 mg/kg/day bosutinib (6.9 and 5.1 times the human exposure at the recommended doses of 400 or 500 mg/day, respectively).