Comparative effectiveness, safety and persistence of ocrelizumab versus natalizumab in multiple sclerosis: A real-world, multi-center, propensity score-matched study.

Ocrelizumab (OCR) and Natalizumab (NTZ) are highly effective treatments widely used in Multiple Sclerosis (MS). However, long-term, real-world comparative data on clinical effectiveness, safety and treatment persistence are limited. This retrospective analysis included relapsing and progressive MS patients initiating treatment at two Italian Universities ("La Sapienza" and "Federico II"). Propensity-score nearest-neighbor matching with a caliper of 0.1 was conducted to adjust for between-group differences in age, sex, previous treatment status, MS phenotype, disease duration, clinical and MRI activity at baseline. Differences in follow-up duration were adjusted with pairwise censoring. Cox proportional hazard regression models were used with Evidence of disease activity (EDA-3) and its components (relapses, MRI activity, and confirmed disability progression) as outcomes. Treatment discontinuation rate and occurrence of adverse events (AEs) were tested using logistic regression. We identified 308 patients (140 on OCR, 168 on NTZ) with a mean (SD) follow-up of 75.7 (30.8) months. Patients treated with OCR were older and less active and less frequenlty naïve at baseline than NTZ-treated patients. The PS-matching procedure retained 140 patients (70 pairs) with a mean follow-up of 55.9 (14.3) months. No significant differences were found between NTZ and OCR in terms of relapses, MRI activity or confirmed disability progression. OCR treatment was associated with a higher incidence of mild to moderate AEs, and higher to comparable treatment persistence. This study provides real-world evidence of comparable effectiveness between OCR and NTZ over a 5-year observation period, with OCR being associated with a higher incidence of AEs and, possibly, higher treatment persistence.