Background and objectives: Ocrelizumab labeling advises contraception for women during treatment and for 6-12 months thereafter. Because pregnancies may occur during this time, it is critical to understand pregnancy and infant outcomes in women with multiple sclerosis (MS) after ocrelizumab exposure.
Methods: Pregnancy cases reported to Roche global pharmacovigilance until 12 July 2023 were analyzed. In utero exposure was defined if the last ocrelizumab infusion occurred in the 3 months before the last menstrual period or during pregnancy. Breastfeeding exposure was defined if at least one infusion occurred while breastfeeding. Fetal death was termed spontaneous abortion (SA) if < 22 complete gestational weeks (GWs) and stillbirth if later. Live births (LBs) were preterm if < 37 complete GWs. Major congenital anomalies (MCAs), infant outcomes, and maternal complications were also analyzed.
Results: In total, 3,244 pregnancies were reported in women with MS receiving ocrelizumab. The median maternal age was 32 years (Q1-Q3: 29-35 years), and most women had relapsing MS (65.6%). Of 2,444 prospectively reported pregnancies, 855 were exposed to ocrelizumab in utero (512 with a known outcome), 574 were nonexposed, and the remaining 1,015 had unknown timing of exposure. Most (83.6%; 956/1,144) of the pregnancies with a known outcome resulted in LBs (exposed, 84.2%; nonexposed, 88.3%). The exposed and nonexposed groups had similar proportions of other important pregnancy outcomes (preterm births, 9.5% vs 8.7%; SA, 7.4% vs 9.1%). Elective abortions were more frequent in the exposed group (7.4%, vs 1.7% in the nonexposed group). The proportion of LBs with MCAs was similar between the exposed and nonexposed groups (2.1% vs 1.9%) and within epidemiologic background rates. In the exposed group, one stillbirth and one neonatal death were prospectively reported.
Discussion: In this analysis of a large pregnancy outcome dataset for an anti-CD20 in MS, in utero exposure to ocrelizumab was not associated with an increased risk of adverse pregnancy or infant outcomes. These data will enable neurologists and women with MS to make more informed decisions around family planning, balancing safety risks to the fetus/infant against the importance of disease control in the mother.