Ocrelizumab has now become one of the most commonly used disease modifying therapies (DMT) for treatment of multiple sclerosis (MS). It is a high-efficacy treatment targeting a specific type of immune cell in the body, called anti-CD20 B cells. These cells can be commonly found in peripheral nervous system, as well as brain tissue and cerebrospinal fluid (CSF). Multiple theories exist in how B cells play a key role in MS pathogenesis, and targeting of these cells decreases inflammation, which in turn reduces relapse rates and slows disability progression. Ocrelizumab has been shown to be effective in reducing risk for relapses and is currently the only DMT available for primary progressive multiple sclerosis (PPMS).
MS more commonly affects young to middle aged women of childbearing age. Current ocrelizumab labeling advises contraception for women during treatment and for 6-12 months thereafter. As many women may become pregnancy during this time period, it was important to determine pregnancy and infant outcomes in women with MS after ocrelizumab exposure.
A large study comparing outcomes in patients exposed to ocrelizumab versus non-exposed patients was recently published. Similar percentages of live births, pre-term births, and spontaneous abortions were reported between both groups. Elective abortions were more frequent in the exposed group. Proportion of major congenital anomalies were similar between both groups as well. Given these findings, it was suggested that utero exposure to ocrelizumab was not associated with an increased risk of adverse pregnancy or infant outcomes.
There were several limitations to this study including, many of the cases had incomplete information or missing data, selection bias towards reporting of “exposed” groups (patients with off-label use during pregnancy or with a shortened wash-out period than the recommended >6 months), and lack of long-term follow-up data regarding infant outcomes and breastfeeding cases.
All in all, though these results may not be generalizable to all pregnant women exposed to ocrelizumab and more studies are needed including longitudinal studies to truly assess exposure outcomes, this is a promising start. It suggests ocrelizumab may be a suitable option for maintaining disease control in women of childbearing age with MS.
Vukusic, S. et al. Pregnancy and infant outcomes in women with multiple sclerosis treated with ocrelizumab. Neurol. Neuroimmunol. Neuroinflamm. 12, e200349 (2025).