Continued Use of Certolizumab Pegol Safe in Pregnant Women with Rheumatoid Arthritis, Study Suggests

There are many rules set for pregnant women to protect the growing fetus. This is particularly true in women with rheumatoid arthritis (RA) due to concerns that the treatments could transfer from mother-to-infants.

However, findings from a pharmacokinetic study brings good news to pregnant women with RA. The results, presented at the Annual European Congress of Rheumatology in Madrid, Spain, showed no or negligible placental transfer of the anti-TNF drug certolizumab pegol (CZP) from mothers to infants during pregnancy.

“For rheumatologists, the management of RA patients wishing to become pregnant involves balancing the need to withdraw certain drugs, while at the same time keeping disease activity under control,” lead author Xavier Mariette said in a press release. “Anti-TNFs are an effective treatment option in RA and spondyloarthritis but, because most cross the placenta, they are often stopped during pregnancy.”

In the United States, an estimated 1.5 million individuals are living with RA. Among pregnant women with RA, many will find that their symptoms go into remission during pregnancy, whereas others may see no change or worsening of symptoms.

The study findings suggest that fetuses may not be exposed to meaningful concentrations of CZP in the uterus, and as a result, suggests that continuing treatment throughout pregnancy may be safe.

“The results of this study support the continuation of CZP treatment during pregnancy when considered necessary to control disease activity,” Mariette said in a release. “We therefore believe that these data will have a significant impact on clinical practice by providing robust information for women who need treatment to keep their disease under control during pregnancy.”

Mariette warned that typical adverse events associated with anti-TNF treatment are still a risk and could affect pregnancy outcomes.

For the study, investigators used a highly sensitive assay to accurately measure the potential level of placental transfer of CZP from mothers to infants. Sixteen pregnant women (30 weeks’ gestation or more) who received a maintenance dose of CZP were included in the study. The final dose of CZP was administered within 35 days of delivery.

Blood samples were collected from the mothers, umbilical cords, infants at delivery, and again from infants at 4 and 8 weeks post-delivery, according to the release.

The results of the study showed that CZP levels were below 0.032 μg/mL in 13 of 14 infant blood samples at birth. Only 1 infant had a minimal CZP level of 0.042 μg/mL at birth. None of the infants had quantifiable levels at 4 and 8 weeks post-delivery.