SARS‐CoV‐2 vaccination and infection in ozanimod‐treated participants with relapsing multiple sclerosis

OBJECTIVE: To investigate the serologic response, predictors of response, and clinical outcomes associated with severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) vaccination and infection in ozanimod‐treated participants with relapsing multiple sclerosis (RMS) from DAYBREAK. METHODS: DAYBREAK (ClinicalTrials.gov‐NCT02576717), an open‐label extension study of oral ozanimod 0.92 mg, enrolled participants aged 18–55 years with RMS who completed phase 1–3 ozanimod trials. Participants who were fully vaccinated against SARS‐CoV‐2 with mRNA or non‐mRNA vaccines, were unvaccinated, and/or had COVID‐19–related adverse events (AEs, with or without vaccination) and postvaccination serum samples were included (n = 288). Spike receptor binding domain (RBD) antibody levels (seroconversion: ≥0.8 U/mL) and serologic evidence of SARS‐CoV‐2 infection (nucleocapsid IgG: ≥1 U/mL) were assessed (Roche Elecsys/Cobas e411 platform). RESULTS: In fully vaccinated participants (n = 148), spike RBD antibody seroconversion occurred in 90% (n = 98/109) of those without serologic evidence of prior SARS‐CoV‐2 exposure (100% [n = 80/80] seroconversion after mRNA vaccination) and in 100% (n = 39/39) of participants with serologic evidence of viral exposure. mRNA vaccination predicted higher spike RBD antibody levels, whereas absolute lymphocyte count (ALC), age, body mass index, and sex did not. COVID‐19–related AEs were reported in 10% (n = 15/148) of fully vaccinated participants—all were nonserious and not severe; all participants recovered. INTERPRETATION: Most ozanimod‐treated participants with RMS mounted a serologic response to SARS‐CoV‐2 vaccination and infection, regardless of participant characteristics or ALC levels. In this analysis, all COVID‐19–related AEs post–full vaccination in participants taking ozanimod were nonserious and not severe.