In Utero Exposure to Ocrevus Not Associated with Elevated Adverse Outcomes in Pregnancy

In a study of the largest available dataset for pregnancy outcomes for an anti-CD20 monoclonal antibody therapy, in utero exposure to Ocrevus (ocrelizumab; Genentech, South San Francisco, CA), a medication used to treat multiple sclerosis (MS), was not associated with an elevated risk of preterm birth, major congenital anomalies (MCAs), or other adverse outcomes. The study results were presented at the 9th Joint meeting of the European and American Committees for Treatment and Research in Multiple Sclerosis (ECTRIMS-ACTRIMS).

The study used data from the Roche safety database, defining in utero fetal exposure as a last Ocrevus infusion occurring within 3 months of last menstrual period or pregnancy. As of January 31, 2023, there were 2065 pregnancies prospectively reported in women who were treated with Ocrevus, and of these, 678 (32.8%) had in utero exposure, 467 (22.5%) had no in utero exposure, and 920 (44.6%) had unknown exposure. Of the in utero exposures, 204 (9.9%) occurred during the first trimester. There were known outcomes in 404 of the prospectively reported pregnancies with in utero exposure.

• In all, 335 of the pregnancies with in utero exposure (82.9%) were delivered by live birth (LB).
• Four (1.0%) were ectopic.
• MCAs were present in 5 of the LBs.

Analysis of the study results suggest that adverse outcomes are not elevated for in utero exposures to Ocrevus in comparison to the general and MS population.

The study authors are from St. Josef Hospital, Hospital Clinico San Carlos, Hôpital Neurologique Pierre Wertheimer, Fondazione IRCCS Ca’Granda Ospedale Maggiore Policlinico, Birgham ande Women’s Hospital, the Wolfson Institute of Population Health at Queen Mary University of London, Roche, and UCSF Weill Institute for Neurosciences.