Aim of the present study was to assess changes in Ocrelizumab (OCR) schedule during the first wave of pandemic in Italy and to evaluate the effect of delayed infusion on clinic/radiological endpoints.

Data were extracted from the Italian MS Register database. Standard interval dosing was defined as an infusion interval ≤ 30 weeks, while extended interval dosing was defined as an infusion interval > 30 weeks at the time of the observation period. Clinico-demographics variables were tested as potential predictors for treatment delay. Time to first relapse and time to first MRI event were evaluated. Cumulative hazard curves were reported along their 95% confidence intervals.

Five-hundred ninety-nine patients with MS from 65 centers were included in the analysis. Mean interval between two OCR infusions was 28.1 weeks before pandemic compared to 30.8 weeks during the observation period, with a mean delay of 2.7 weeks (p <0.001). No clinico-demographic factors emerged as predictors of infusion postponement, except for location of MS centers in the North of Italy. Six clinical relapses and 17 MRI activity reports were recorded in the whole RMS group during the follow-up period.

Despite the significant extension of OCR infusion interval during the first wave of pandemic in Italy, a very small incidence of clinical/radiological events occurred in follow-up period, thus confirming the high efficacy and the long-lasting efficacy of OCR.