, new research confirmed.
Registry data showed no differences in health or development in the first 3 years of life among infants exposed to natalizumab, ocrelizumab, rituximab, or ofatumumab, compared with unexposed infants.
“Most monoclonal antibody medications for multiple sclerosis are not currently approved for use while a mother is breastfeeding,” even though the disease can develop during a person’s reproductive years, study investigator Kerstin Hellwig, MD, with Ruhr University in Bochum, Germany, said in a news release.
“Our data show infants exposed to these medications through breastfeeding experienced no negative effects on health or development within the first 3 years of life,” Dr. Hellwig said.
The findings were released ahead of the study’s scheduled presentation at the annual meeting of the American Academy of Neurology.
Registry Data and Analysis
Using the German MS and Pregnancy Registry, researchers identified 183 infants born to mothers taking mAbs while breastfeeding — 180 with a diagnosis of MS and three with a diagnosis of NMOSD. The infants were matched to 183 unexposed infants (control group).
Exposure to mAbs during lactation started a median of 19 days postpartum and lasted for a median of 172 days. The most commonly used mAb during lactation was natalizumab (125 women), followed by ocrelizumab (34 women), rituximab (11 women), and ofatumumab (10 women).
Among the entire infant cohort, two were first exposed to natalizumab and then ocrelizumab; one was exposed to rituximab and then ocrelizumab; three had been previously breastfed on glatiramer acetate and two on interferons.
The primary outcomes were hospitalizations, antibiotic use, developmental delay, and weight during the first 3 years of life in mAb-exposed versus unexposed infants.
In adjusted regression analyses, mAb exposure during breastfeeding was not significantly associated with annual hospitalization (rate ratio [RR], 1.23; P = .473), annual systemic antibiotic use (RR, 1.55; P = .093), developmental delay (odds ratio, 1.16; P = .716), or weight.
A limitation of the study was that only about a third of the infants were followed for the full 3 years. Therefore, Dr. Hellwig said, the results for the third year of life are less meaningful than for years 1 and 2.
‘Reassuring’ Data
Reached for comment, Edith L. Graham, MD, Department of Neurology, Multiple Sclerosis and Neuroimmunology, Northwestern University, Chicago, Illinois, noted that this is the largest group of breastfed infants exposed to mAbs used to treat MS and said the data provide “reassuring infant outcomes with no increase in hospitalization, antibiotic use, or developmental delay.”
Dr. Graham noted that recent publications have reported more on the use of anti-CD20 mAbs (ocrelizumab/rituximab/ofatumumab) while breastfeeding, “and this study adds data for patients on natalizumab.”
“It will be important to know how infusion timing after birth impacts transfer of monoclonal antibodies depending on the milk stage as it transitions from colostrum to mature milk in the first month postpartum,” Dr. Graham said.
“While infection rates of infants are reassuring, data on allergies in the exposed infants would be interesting to look at as well,” she added. “While these infusions are not orally bioavailable, we do not know the full extent of impact on the neonatal gut microbiome.”
In addition, Dr. Graham said it would be important to know whether drugs administered monthly, such as natalizumab and ofatumumab, accumulate in the breast milk at higher levels than medications such as ocrelizumab and rituximab, which are administered twice a year.
The German MS and pregnancy registry was partly supported by the Innovation Fund of the Federal Joint Committee, Almirall Hermal GmbH, Biogen GmbH Germany, Hexal AG, Merck Serono GmbH, Novartis Pharma GmbH, Roche Deutschland GmbH, Sanofi Genzyme, and Teva GmbH. Dr. Hellwig and Dr. Graham had no relevant disclosures.
A version of this article appeared on Medscape.com.