Ocrelizumab in early relapsing-remitting multiple sclerosis: first interim analysis of the MUSPO Italian prospective cohort

Background Real-world evidence on ocrelizumab in early, minimally pretreated relapsing multiple sclerosis (MS) patients remains limited.Objective To describe baseline demographic, clinical, radiological, and treatment characteristics of the MUSPO cohort.Methods MUSPO is a prospective, multicenter, observational study. Enrollment occurred from September 2023 to May 2025. Adults with relapsing-remitting MS (RRMS), including a rapidly evolving severe RRMS (RES) group, were enrolled similar to 6 months after starting ocrelizumab. MRI was acquired according to clinical practice with centralized reading. NEDA-plus (absence of relapses, disability worsening, MRI activity, brain atrophy, and cognitive worsening) will be assessed at years 1-4. Baseline descriptive statistics were used.Results Of 208 patients enrolled across 31 Italian sites, 199 were eligible (RRMS N = 59; RES N = 140) for the interim analysis. Median Expanded Disability Status Scale was 2.0 (IQR 1.0-3.0), indicating mild disability. Prior disease-modifying therapy (DMT) exposure occurred in 59/199 patients (29.6%); time from last DMT to ocrelizumab was a median 1.4 months (IQR 0.7-2.0). MRI at diagnosis was available for 188/199 patients (94.5%), gadolinium used in 157/188 scans (83.5%). Baseline MRI was available for all patients with gadolinium administered in 166/199 cases (83.4%). Cognitive assessment using the Symbol Digit Modalities Test was completed by 150/199 (75.4%) of patients.Conclusions The MUSPO study captures a predominantly young, mildly disabled, early-treated cohort, some of whom have prior DMT exposure. Together with comprehensive baseline MRI and limited prior DMT use, these features provide a robust foundation to evaluate NEDA-plus and other longitudinal effectiveness endpoints in Italian practice.