ABSTRACT
Introduction: Real-world evidence studies regarding the effectiveness and safety of disease-modifying therapies are useful for clinical practice and for assessing the risk-benefit of some health policy interventions. Objective(s): To evaluate safety and effectiveness outcomes in year 1 and year 2 in patients receiving antiCD20 monoclonal antibodies. Method(s): Longitudinal observational study of MS patients under regular care at the Programa de Esclerosis Multiple UC in Chile who received at least one dose of ocrelizumab or rituximab between June 2018 and April 2022. Result(s): A total of 229 patients were included, 219 using Ocrelizumab and 10 using Rituximab. 163 patients had relapsingremitting MS (RRMS), 68% female, mean age at antiCD20 34.3+8.5 years, mean disease duration 5.6+5.4 years, and median baseline EDSS 1.5(0-6.0). 35 had primary progressive MS (PPMS), 54% female, mean age at antiCD20 47+12 years, mean disease duration 6.3+6.3 years and median EDSS 4.0(1.0-7.0). 31 had secondary progressive MS (SPMS), 64% female, mean age at antiCD20 50.4+9.7 years, mean disease duration 16.4+10.1 years and median EDSS 6.0(1.0-7.0). Before antiCD20, mean annualized relapse rate (ARR) was 0.7+0.5 for RRMS, and 0.2+0.4 for PPMS and SPMS patients, and MRI activity (newT2/Gd+) was observed in 84.8% of RRMS, 60% of PPMS and 40.7% of SPMS patients. Mean ARR in years 1 and 2 was 0 in RRMS and PPMS, 0.05+0.2 in year 1 and 0 in year 2 for SPMS. NewT2/Gd+ in years 1 and 2 were observed in 11.4% and 8.3% in RRMS, 21.4% and 0 in PPMS, and 0 in SPMS. Year 1 and 2 EDSS progression was observed in 0% and 3.6% of RRMS, 0 and 15.4% in PPMS, and 18.1% and 21.4% in SPMS. Years 1 and 2 NEDA3 was obtained in 82.6% and 94.6% of RRMS, 70% and 87.5% of PPMS and 90% and 87.5% of SPMS. Infusion Reactions were observed in 35% during the first dose, decreasing with each infusion (13.5% in the fourth infusion), all were considered mild. The most frequent year 1 adverse event were COVID-19 (n=5), upper tract infection (n=4), diarrhoea (n=4) and urinary tract infection (n=4). The most frequent year 2 adverse events were COVID-19 (n=4) and skin infection (n=3). One patient with previous history of breast cancer developed a tumour recurrence during the second year of treatment. Conclusion(s): This study supports robust effectiveness outcomes in a real-world cohort, with a consistent safety profile in patients receiving care at a specialized MS Unit.