Researchers suggest that certolizumab pegol is safe to use in the second and third trimesters of pregnancy.
The results were released at the 2017 Annual Congress of the European League Against Rheumatism.
Dr. Xavier Mariette, of the Bicêtre Hospital in Paris, France, and colleagues used a sensitive immunoassay that was developed to detect certolizumab pegol.
They found no measurable levels in 13 out of 14 infant blood samples obtained at birth and in all infant samples at weeks 4 and 8 after birth.
The study included 16 pregnant women at ≥30 weeks gestation who were receiving certolizumab pegol at a maintenance dose (200 milligrams every 2 weeks or 400 milligrams every 4 weeks) for any of a range of approved indications, including rheumatoid arthritis, psoriatic arthritis, axial spondyloarthritis/ankylosing spondylitis, and Crohn's disease.
All patients had received their last dose within 35 days prior to delivery.
"The [...] study is the only clinical research that demonstrates how an effective anti-TNF [tumor necrosis factor] shows minimal to no placental transfer from mother to infant," Dr. Mariette noted in a news release.
He also said that the results are "good news" for pregnant women with active inflammatory disease. Most anti-TNF agents have been found to cross the placenta and are usually withdrawn during pregnancy.
Data suggest a lack of in utero exposure
In the study, blood samples were collected from the mothers, umbilical cords, and infants at delivery, and from the infants again at weeks 4 and 8 post-delivery.
Certolizumab pegol concentration was measured with a drug-specific immunoassay, which is more sensitive than earlier certolizumab pegol immunoassays.
Of the 16 infants delivered, two samples were excluded (in one case due to missing data, and in the other case, due to implausible pharmacokinetic data).
The study found that certolizumab pegol levels were below lower levels of quantification in 13 out of 14 infant blood samples at birth and in all samples at weeks 4 and 8. One infant had a minimal certolizumab pegol level of 0.042ug/mL (infant/mother ratio of 0.009).
No anti-certolizumab pegol antibodies were detected in mothers, umbilical cords, or infants.
Dr. Mariette said that the data suggest a lack of in utero exposure during the second and third trimesters, thereby justifying support for ongoing certolizumab pegol treatment during pregnancy.