Real-world effectiveness of natalizumab treatment in patients with relapsing multiple sclerosis in Argentina and Chile.

Maria Celica Ysrraelit,Mario Rivera Kindel,Vladimiro Sinay,Mario Javier Halfon,Liliana Patrucco,Raul Piedrabuena,Alejandro Caride,Vanina Eleonor Diaz Aragunde

doi:10.1590/0004-282x-anp-2020-0303

Abstract

The real-world effectiveness of natalizumab in people with relapsing multiple sclerosis (PwRMS) in Argentina and Chile has not been reported. To evaluate the effectiveness of natalizumab treatment in PwRMS in Argentina and Chile, in clinical practice. We conducted a multicenter retrospective and observational study. We reviewed the medical records of PwRMS who had been treated with natalizumab for at least one year, without any interruption in MS treatment that lasted more than 12 weeks. We analyzed changes in annualized relapse rate (ARR), Expanded Disability Status Scale (EDSS) score and magnetic resonance imaging (MRI). We enrolled 117 PwRMS treated with natalizumab. Natalizumab treatment was associated with a significant reduction in ARR from baseline after one year and two years of treatment (from 1.97 to 0.06 and 0.09 respectively; p<0.01 at each time point). From baseline, EDSS scores were reduced by 0.71 and 0.73 points at one and two years, respectively (p<0.01). No worsening of disability was observed in 82.9 and 67.5% of PwRMS at one and two years, respectively. The improvement in disability was 44.4% at one year and 39.3% at two years. During natalizumab treatment, the number of relapse-related hospitalizations was significantly reduced (p<0.01). MRI lesions (new/enlarging T2 or gadolinium-enhancing) were significantly reduced, compared with baseline. No evidence of disease activity was observed in 65% at two years of natalizumab treatment. Natalizumab significantly reduced disease activity in PwRMS in Argentina and Chile, in clinical practice. Natalizumab also decreased the number of hospitalizations compared with pre-natalizumab treatment.

Highlights

METHODSMultiple sclerosis (MS) is an inflammatory and neurodegenerative disease of the central nervous system (CNS) with estimated prevalences of 38.2 and 5.7 per 100,000 inhabitants in the city of Buenos Aires, Argentina, and in Chile, respectively[1,2,3]
Given the few data in our region, we aimed to evaluate the effectiveness of natalizumab in clinical practice in Argentina and Chile through collection of data on demographics, frequency of relapse-related hospitalizations, clinical observations and magnetic resonance imaging (MRI) from clinical records of people with relapsing multiple sclerosis (PwRMS) treated with natalizumab
The findings observed in this study on real-world evidence, which was carried out in Argentina and Chile, were consistent with data from previous studies on natalizumab conducted in other regions

Summary

Introduction

METHODSMultiple sclerosis (MS) is an inflammatory and neurodegenerative disease of the central nervous system (CNS) with estimated prevalences of 38.2 and 5.7 per 100,000 inhabitants in the city of Buenos Aires, Argentina, and in Chile, respectively[1,2,3]. In the phase III AFFIRM study[4], natalizumab reduced the sustained progression of disability by 42% at two years and the relapse rate by 68% at one year. In the SENTINEL study[5], the combination of natalizumab and interferon β1a reduced the sustained progression of disability by 24% at two years and the relapse rate by 54% at one year, in comparison with interferon β1a. The real-world effectiveness of natalizumab in people with relapsing multiple sclerosis (PwRMS) in Argentina and Chile has not been reported. The number of relapse-related hospitalizations was significantly reduced (p

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