Drug exposure to infants born to mothers taking Elexacaftor, Tezacaftor, and Ivacaftor

Elexacaftor, tezacaftor, ivacaftor (ETI) have been associated with marked clinical improvements in adults with CF, which appears to be associated with increased fertility. However, maternal and fetal effects of therapy continued during pregnancy are not well understood. We collected maternal blood, infant blood, cord blood, and breast milk from 3 mother-infant pairs from women who elected to remain on ETI therapy while pregnant. Our results demonstrated relatively high levels of ETI in cord blood, suggesting placental transfer of these compounds, as well as low levels of ETI in breast milk and infant blood, suggesting further transfer of these compounds to breast-fed infants in the postnatal period. These data underscore the need for larger studies on the effects of modulator surrounding reproduction.