A Study Evaluating B Cell Levels In Infants Of Lactating Women With CIS Or MS Receiving Ocrelizumab

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 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