Extended interval dosing of ocrelizumab in patients with multiple sclerosis is not associated with meaningful differences in disease activity.

Risk concerns related to ocrelizumab treatment for multiple sclerosis (MS) during the COVID-19 pandemic caused infusion delays with extended interval dosing (EID). We reviewed medical records of patients on ocrelizumab to determine whether EID maintains its effectiveness compared to standard interval dosing (SID). Among 361 patients, 231 (64%) and 123 (34%) had at least one infusion with infusion intervals of ⩾8 months and ⩾12 months, respectively. There were no differences in demographics or clinical profiles between the SID and EID groups. No significant differences between rates of breakthrough activity among relapsing-remitting patients were observed between SID (three patients) and EID (seven patients).