MS drug in breastmilk: new study checks baby safety
NCT ID NCT04998851
First seen Jun 25, 2026 · Last updated Jun 27, 2026 · Updated 1 time
Summary
This study looked at how much of the multiple sclerosis drug ocrelizumab gets into breastmilk and whether it affects babies' immune cells. Twenty-six breastfeeding mothers with MS or clinically isolated syndrome took part. Researchers measured drug levels in breastmilk and checked B cell counts in their infants after the mothers received their first postpartum dose.
What this could mean
Our plain-language read of the trial. This is informational only, not medical advice or a prediction.
- Active substance
- ocrelizumab
- What this could lead to
- If successful, this study could help doctors understand whether it is safe for mothers with MS to breastfeed while taking ocrelizumab.
- What could go wrong
- This is a small, completed study with only 26 participants, so results may not apply to all mothers. It only measured short-term effects on infants.
This is an AI summary of the original study and may miss details. Read our disclaimer.
Study facts
What this study's own registry entry says, in plain language.
- Phase
-
Phase 4
Runs after approval, following long-term safety and how well the treatment works in everyday use.
- Participants
-
26 people
The number who actually took part.
- Started
-
Sep 2021
- Finished
-
Jan 2025
- Lead sponsor
-
A company
The lead sponsor is a pharmaceutical, biotech, or medical-device company.
Who can take part
This study's own entry requirements. Only the study team can say for certain whether you qualify.
- Ages
-
18 to 40 years
- Sex
-
Female participants only
- Healthy volunteers
-
Not accepted
This study is not open to healthy volunteers. The entry requirements below say who it is open to.
Show the full entry requirements Hide the full entry requirements
Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.
Inclusion Criteria: * Woman is between 18 and 40 years of age at screening * Woman is willing to breastfeed for at least 60 days after the first post-partum ocrelizumab infusion (this decision is to be taken prior to and independent from study participation) * Woman is willing to provide breastmilk samples * Woman has a diagnosis of MS or CIS (in line with the locally approved indications) * Woman has delivered a healthy term singleton infant (≥37 weeks gestation) * Infant is between 2-24 weeks of age at the time of the mother's first post-partum dose of ocrelizumab * For women who received commercial ocrelizumab (OCREVUS) before enrolment: documentation that last exposure to ocrelizumab occurred more than 3 months before the last menstrual period (LMP) and was given at the approved dose of 2 x 300 mg or 1 x 600 mg * Woman agrees to use acceptable contraceptive methods during the study Exclusion Criteria related to the Mother: * Hypersensitivity to ocrelizumab or to any of its excipients * Received last dose of ocrelizumab \<3 months before the LMP or during pregnancy * Active infections (may be included once the infection is treated and is resolved; women with bilateral mastitis infection should not have samples collected until the infection is completely resolved) * Prior or current history of primary or secondary immunodeficiency, or woman in an otherwise severely immunocompromised state * Known active malignancies, or being actively monitored for recurrence of malignancy * History of breast implants, breast augmentation, breast reduction surgery or mastectomy * Prior or current history of chronic alcohol abuse or drug abuse * Positive screening tests for hepatitis B * Treatment with a DMT for CIS or MS during pregnancy and/or first weeks post-partum, with the exception of formulations of interferon-beta, glatiramer acetate or pulsed corticosteroids * Treatment with drugs known to transfer to the breastmilk and with established or potential deleterious effects for the infant * Treatment with any investigational agent within 6 months or five half-lives of the investigational drug prior to the LMP Exclusion Criteria related to the Infant: * \>24 weeks of life at the time of the mother's first dose of ocrelizumab * Any abnormality that may interfere with breastfeeding or milk absorption * Active infection (may be included once the infection resolves) * Infant has any other medical condition or abnormality that, in the opinion of the investigator, could compromise the infant's ability to participate in this study, including interference with the interpretation of study results * At least one documented brief resolved unexplained event (BRUE), as defined by the 2016 Guidelines of the American Academy of Pediatrics
Get updates
Get notified about this study
Sign up to get updates when this study changes or when new studies for Clinically isolated syndrome are added.
Genom att skicka in godkänner du våra Användarvillkor
Conditions
The condition(s) this trial relates to.
As listed by the trial registrant
The condition terms exactly as the trial's registrant entered them.
Contacts and locations
Locations
-
Brigham and Womens Hospital
Boston, Massachusetts, 02115, United States
-
Hosp. Clinico San Carlos
Madrid, 28040, Spain
-
Hospital of the University of Pennsylvania
Philadelphia, Pennsylvania, 19104, United States
-
Memorial Healthcare Institute for Neurosciences and Multiple Sclerosis
Owosso, Michigan, 48867, United States
-
Northwestern Memorial Hospital
Chicago, Illinois, 60611-2987, United States
-
Queen Mary University of London
London, EC1M 6BQ, United Kingdom
-
University Of Colorado
Aurora, Colorado, 80045, United States
-
University of California San Francisco
San Francisco, California, 94158, United States
More trials for these conditions
Other studies related to the condition(s) this trial covers.
- Can exercise rebuild muscle and balance in MS?
- Can diet ease the crushing fatigue of multiple sclerosis?
- One-Time CAR-T infusion tested against progressive MS
- Can PET scans reveal hidden brain inflammation in MS?
- Can a pill rebuild the Brain's insulation? MS trial puts remyelination to the test
- Migraines and tension headaches may be hidden companions to multiple sclerosis