Risk Summary

Based on animal reproduction studies, SIVEXTRO may cause fetal harm when administered to pregnant women. The available data on the use of SIVEXTRO in pregnant women are insufficient to evaluate for a drug-associated risk of major birth defects, miscarriage, or adverse maternal or fetal outcomes. Advise pregnant women of the potential risks to a fetus. Fetal developmental toxicities were observed in mice and rats treated with SIVEXTRO. In embryo-fetal studies in mice and rats, tedizolid phosphate was shown to produce fetal developmental toxicities in mice and maternal toxicity and fetal developmental toxicities in rats. Tedizolid phosphate administered orally during organogenesis to pregnant animals was associated with reduced fetal weights and an increased incidence of costal cartilage anomalies in the absence of maternal toxicity in mice; and maternal toxicity, decreased fetal weights, and increased skeletal variations in rats at plasma exposures approximately 4- and 6-times respectively, the human plasma exposure at the maximum recommended human dose (MRHD) of 200 mg/day. In female rats administered tedizolid phosphate during organogenesis through lactation, there was no evidence of fetal toxicity, developmental delays, or impaired reproduction in the offspring at plasma exposures approximately equivalent to the human plasma exposure at the MRHD. (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. 

Data

Animal Data

In an embryo-fetal development study, tedizolid phosphate administered orally to pregnant mice at doses of 1, 5, and 25 mg/kg/day during organogenesis (Gestational Day [GD] 6 to GD15) was associated with fetal developmental effects occurring in the absence of maternal toxicity, including reduced fetal weights and an increased incidence of costal cartilage anomalies at the high dose (approximately 4-times the human plasma exposure at the MRHD based on plasma AUC comparison). Tedizolid phosphate administered orally at doses of 2.5, 5, and 15 mg/kg/day to pregnant rats during organogenesis (GD6 through GD17) was associated with maternal toxicity (reduced maternal body weights), decreased fetal weights, and increased skeletal variations including reduced ossification of the sternebrae, vertebrae, and skull at the high dose of 15 mg/kg/day (approximately 6-times the human plasma exposure at the MRHD based on plasma AUC comparison). The doses not associated with fetal toxicity in mice and maternal and fetal toxicity in rats were 5 and 2.5 mg/kg/day respectively (for both species approximately equivalent to the human plasma exposure at the MRHD based on plasma AUC comparison). 

In a pre-postnatal study, oral tedizolid phosphate administered to female rats at doses of 1.25, 2.5, and 3.75 mg/kg/day during gestation and lactation (GD6 through Lactational Day 20) was not associated with maternal toxicity, fetal toxicity, developmental delays, or impaired reproduction at doses up to the high dose of 3.75 mg/kg/day (approximately equivalent to the human plasma exposure at the MRHD based on plasma AUC comparison).