Risk Summary

Based on findings from human data, animal studies, and the mechanism of action, Decitabine for Injection can cause fetal harm when administered to a pregnant woman [see Clinical Pharmacology (12.1) and Nonclinical Toxicology (13.1)]. Limited published data on Decitabine for Injection use throughout the first trimester during pregnancy describe adverse developmental outcomes including major birth defects (structural abnormalities). In animal reproduction studies, administration of decitabine to pregnant mice and rats during organogenesis caused adverse developmental outcomes including malformations and embryo-fetal lethality starting at doses approximately 7% of the recommended human dose on a mg/m2 basis (see Data). Advise pregnant women of the potential risk to a fetus. 

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. The estimated background risk of major birth defects and miscarriage in the U.S. general population is 2% to 4% and 15% to 20% of clinically recognized pregnancies, respectively. 

Data

Human Data

A single published case report of decitabine pregnancy exposure in a 39-year old woman with a hematologic malignancy described multiple structural abnormalities after 6 cycles of therapy in the 18th week of gestation. These abnormalities included holoprosencephaly, absence of nasal bone, mid-facial deformity, cleft lip and palate, polydactyly and rocker-bottom feet. The pregnancy was terminated. 

Animal Data

In utero exposure to decitabine causes temporal related defects in the rat and/or mouse, which include growth suppression, exencephaly, defective skull bones, rib/sternabrae defects, phocomelia, digit defects, micrognathia, gastroschisis, micromelia. Decitabine inhibits proliferation and increases apoptosis of neural progenitor cells of the fetal CNS and induces palatal clefting in the developing murine fetus. Studies in mice have also shown that decitabine administration during osteoblastogenesis (day 10 of gestation) induces bone loss in offspring. 

In mice exposed to single IP (intraperitoneal) injections (0, 0.9 and 3 mg/m2, approximately 2% and 7% of the recommended daily clinical dose, respectively) over gestation days 8, 9, 10 or 11, no maternal toxicity was observed but reduced fetal survival was observed after treatment at 3 mg/m2 and decreased fetal weight was observed at both dose levels. The 3 mg/m2 dose elicited characteristic fetal defects for each treatment day, including supernumerary ribs (both dose levels), fused vertebrae and ribs, cleft palate, vertebral defects, hind-limb defects and digital defects of fore- and hind-limbs. 

In rats given a single IP injection of 2.4, 3.6 or 6 mg/m2 (approximately 5%, 8%, or 13% the daily recommended clinical dose, respectively) on gestation days 9 to 12, no maternal toxicity was observed. No live fetuses were seen at any dose when decitabine was injected on gestation day 9. A significant decrease in fetal survival and reduced fetal weight at doses greater than 3.6 mg/m2 was seen when decitabine was given on gestation day 10. Increased incidences of vertebral and rib anomalies were seen at all dose levels, and induction of exophthalmia, exencephaly, and cleft palate were observed at 6 mg/m2. Increased incidence of foredigit defects was seen in fetuses at doses greater than 3.6 mg/m2. Reduced size and ossification of long bones of the fore-limb and hind-limb were noted at 6 mg/m2. 

The effect of decitabine on postnatal development and reproductive capacity was evaluated in mice administered a single 3 mg/m2 IP injection (approximately 7% the recommended daily clinical dose) on day 10 of gestation. Body weights of males and females exposed in utero to decitabine were significantly reduced relative to controls at all postnatal time points. No consistent effect on fertility was seen when female mice exposed in utero were mated to untreated males. Untreated females mated to males exposed in utero showed decreased fertility at 3 and 5 months of age (36% and 0% pregnancy rate, respectively). Follow up studies indicated that treatment of pregnant mice with decitabine on gestation day 10 was associated with a reduced pregnancy rate resulting from effects on sperm production in the F1-generation.