Ivacaftor and tezacaftor

Placental transfer has been observed in animal studies. In pregnant rats receiving approximately the MRHD from gestation Day 6 through lactation Day 18, tezacaftor had no adverse developmental effects on pups. In rabbits receiving maternally toxic tezacaftor doses (approximately 0.4 times the maximum recommended human dose [MRHD]), lower fetal body weights were observed. In rats receiving maternally toxic ivacaftor doses (approximately 2 times the MRHD) decreased fetal body weights and early developmental delays in pinna detachment, eye opening, and righting reflex occurred. In pregnant rats and rabbits, ivacaftor did not affect fetal survival at exposures up to 6 and 16 times the MRHD, respectively. There are no controlled data in human pregnancy.

US FDA pregnancy category Not Assigned: The US FDA has amended the pregnancy labeling rule for prescription drug products to require labeling that includes a summary of risk, a discussion of the data supporting that summary, and relevant information to help health care providers make prescribing decisions and counsel women about the use of drugs during pregnancy. Pregnancy categories A, B, C, D and X are being phased out.

Benefit should outweigh risk

US FDA pregnancy category: Not assigned

Risk Summary: There is limited and incomplete data on use of this drug or its individual components in pregnant women to inform a drug-related risk; reproductive and developmental studies in rats and rabbits did not show teratogenicity or adverse developmental effects.