How Safe is Anti–IL-6 Therapy During Pregnancy?

TOPLINE:

The maternal and neonatal outcomes in pregnant women treated with anti–interleukin (IL)-6 therapy for COVID-19 are largely favorable, with transient neonatal cytopenia observed in around one third of the babies being the only possible adverse outcome that could be related to anti–IL-6 therapy.

METHODOLOGY:

• Despite guidance, very few pregnant women with COVID-19 are offered evidence-based therapies such as anti–IL-6 due to concerns regarding fetal safety in later pregnancy.
• In this retrospective study, researchers evaluated maternal and neonatal outcomes in 25 pregnant women with COVID-19 (mean age at admission, 33 years) treated with anti–IL-6 (tocilizumab or sarilumab) at two tertiary hospitals in London.
• Most women (n = 16) received anti–IL-6 in the third trimester of pregnancy, whereas nine received it during the second trimester.
• Maternal and neonatal outcomes were assessed through medical record reviews and maternal medicine networks, with follow-up for 12 months.
• The women included in the study constituted a high-risk population with severe COVID-19; 24 required level two or three critical care. All women were receiving at least three concomitant medications due to their critical illness.

TAKEAWAY:

• Overall, 24 of 25 women treated with IL-6 receptor antibodies survived until hospital discharge.
• The sole death occurred in a woman with severe COVID-19 pneumonitis who later developed myocarditis and cardiac arrest. The physicians believed that these complications were more likely due to severe COVID-19 rather than anti–IL-6 therapy.
• All pregnancies resulted in live births; however, 16 babies had to be delivered preterm due to COVID-19 complications.
• Transient cytopenia was observed in 6 of 19 babies in whom a full blood count was performed. All the six babies were premature, with cytopenia resolving within 7 days in four babies; one baby died from complications associated with extreme prematurity.

IN PRACTICE:

“Although the authors found mild, transitory cytopenia in some (6 of 19) exposed infants, most had been delivered prematurely due to progressive COVID-19–related morbidity, and distinguishing drug effects from similar prematurity-related effects is difficult,” wrote Steven L. Clark, MD, from the Department of Obstetrics and Gynecology, Baylor College of Medicine, Houston, in an accompanying editorial.

SOURCE:

The study was led by Melanie Nana, MRCP, from the Department of Obstetric Medicine, St Thomas’ Hospital, London, England. It was published online on August 5, 2024, in The Lancet Rheumatology.

LIMITATIONS:

The study was retrospective in design, which may have introduced bias. The small sample size of 25 women may have limited the generalizability of the findings. Additionally, the study did not include a control group, which made it difficult to attribute outcomes solely to anti–IL-6 therapy. The lack of long-term follow-up data on the neonates also limited the understanding of potential long-term effects.

DISCLOSURES:

This study did not receive any funding. Some authors, including the lead author, received speaker fees, grants, or consultancy fees from academic institutions or pharmaceutical companies or had other ties with various sources.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.