Women with inflammatory bowel disease treated with Humira or Remicade during pregnancy did not have increased risk for adverse pregnancy or developmental outcomes, according to research presented at the 10th Congress of ECCO in Barcelona, Spain.
Researchers evaluated drug levels of Humira (adalimumab, AbbVie) or Remicade (infliximab, Janssen) in the cord blood of newborns exposed during pregnancy and correlated them with their mothers’ levels, duration of therapy and time to drug clearance. They recruited 89 pregnant women with IBD at 14 centers across Denmark, Australia and New Zealand between 2012 and 2014 and measured drug levels using an enzyme-linked immunoassay at delivery. Positive newborns were tested every 3 months until they were negative.
Overall, five participants miscarried and four failed blood collection resulting in 44 mother-baby pairs exposed to infliximab and 36 exposed to adalimumab; 49% also were receiving thiopurines. Development was deemed normal in all babies based on routine infant checks, although 4% had preterm birth, 4% were small for gestational age and 2.5% had congenital malformations.
Time since last dose and drug levels were inversely correlated in both cord blood (infliximab: r = –0.58; adalimumab: r = –0.41; both P < .0001) and the mothers’ blood (infliximab: r = –0.63; adalimumab: r = –0.64; both P < .0001). Drug levels in cord blood also were correlated with the mothers’ drug levels (infliximab: r = 0.67; adalimumab: r = 0.64; both P < .0001).
Last dose was at median gestational week 30 (8-37) in patients receiving infliximab and 35 (14-41) in patients receiving adalimumab, and drug was stopped before gestational week 30 in 31% overall, but this did not increase risk for disease activity in the third trimester or postpartum. Median drug levels were 2 µg/mL (0-22.2 µg/mL) in mothers and 5.9 µg/mL (0.12-28.7 µg/mL) in cord blood for infliximab and 1.5 µg/mL (0-10 µg/mL) in mothers and 2 µg/mL (0-12.1 µg/mL) in cord blood for adalimumab. Drug levels were significantly lower when drug was stopped before gestational week 30.
The researchers concluded that there was no increased risk for adverse pregnancy or developmental outcomes in these patients. Mother and cord blood drug levels were inversely correlated with time since last dose, and drug levels in cord blood correlated with drug levels in the mother at delivery. Stopping drug before week 30 significantly reduced fetal exposure without increasing disease activity, although drug clearance took up to 1 year.
“Therefore, live vaccinations should be avoided prior to 1 year unless drug clearance is documented,” the researchers wrote.
At the time of presenting this data, 44 (55%) of the babies have cleared drug, but testing is ongoing for 36 of them. Median time to clearance was 6 (0-12) months for both infliximab and adalimumab, and drug type and weeks since last dose predicted clearance by 3 months (area under the receiver operating curve, 0.81; P = .002). – by Adam Leitenberger
