Relapsing-remitting and primary progressive multiple sclerosis treated with ocrelizumab: A comparative study

Objectives: To compare the clinical and radiological effectiveness of ocrelizumab in primary progressive multiple sclerosis (PPMS) and relapsing-remitting multiple sclerosis (RRMS) in a clinical practice setting and describe its tolerability and adverse events.Methods: A retrospective observational cohort study was conducted comparing clinical and magnetic resonance imaging (MRI) data of all patients with (pw)PPMS and RRMS who had received treatment with ocrelizumab at least one cycle and have been followed up for one year at minimum.Results: 42 patients (27 women) treated with ocrelizumab: 29 had RRMS and 13 PPMS. The follow-up period was 26.4 +/- 8.4 months. The proportion of pwRRMS with no evidence of disease activity (NEDA) in the first year was 69.2% and in the second was 80%. In the first year, radiological activity was reduced by 80.0% in pwRRMS and 91.7% in pwPPMS. In the second year, radiological activity was completely reduced in both groups. A statistically significant difference (p<0.05) was observed between the pre-ocrelizumab rate of disability progression vs. the first year rate of progression for pwRRMS and pwPPMS. However, an increase in the disability progression rate in the second year of treatment was found in pwPPMS. Ocrelizumab was mostly well tolerated and some adverse effects were reported: infusion-related reactions (IRRs) were the most frequent adverse event, followed by infections and hematological side effects. Discontinuations were due to infections, hematological complications, and perception of ineffectiveness. Conclusions: Ocrelizumab was very effective in reducing relapses and MRI activity. The rate of progression was slowed down; however, the effect was more evident for pwRRMS than for pwPPMS over time.