Multiple Sclerosis and Related Disorders 47 (2021) 102664 Available online 2 December 2020 2211-0348/© 2020 Elsevier B.V. All rights reserved. Usage trend of oral drugs for multiple sclerosis patients in Argentina Ricardo Alonso a, h , Orlando Garcea a , María Barbara Eizaguirre a , Federico Man b , Abril Lopez Bizzo b , Leila Cohen a , Juan I Rojas c , Liliana Patrucco c , Edgardo Cristiano c , Cecilia Pita a , Veronica Tkachuk d , Maria Eugenia Balbuena d , Edgar Carnero Contentti e , Pablo Lopez e , Juan Pablo Pettinichi e , Norma Deri f , Jimena Miguez g , Agustín Pappolla g , Luciana Lazaro h , Nora Fernadez Liguori h , Jorge Correale i , Adriana Carr´ a j, k , Berenice A Silva a, * a Centro Universitario de Esclerosis Múltiple, Hospital JM Ramos Mejía b Servicio de Neurología, Hospital Ramos Mejía c Centro de esclerosis múltiple de Buenos Aires, CABA d Secci´ on de Esclerosis Múltiple y Enfermedades Desmielinizantes, Servicio de Neurología - Hospital de Clínicas Jos´ e de San Martín, CABA e Neuroimmunology Unit, Department of Neuroscience, Hospital Aleman, Buenos Aires f Centro de Investigaciones Diabaid, CABA g Servicio de Neurología, Hospital Italiano de Buenos Aires, Buenos Aires h Servicio de Neurología. Sanatorio Guemes i Departamento de Neurología - FLENI, CABA. j Secci´ on de Enfermedades Desmielinizantes - Hospital Brit´ anico, CABA. k Instituto de Neurociencias - Fundaci´ on Favaloro/INECO, CABA ABSTRACT Introduction: Over the past decade, numerous disease modifying drugs (DMDs) for relapsing- remitting multiple sclerosis (RRMS) have been approved in Argentina. The use of oral DMDs (oDMDs) has increased in recent years, although real-life data in our region is limited. We aimed to describe the tendency in the use of oDMDs (as frst treatment option or after switch) in relationship with their approval in Argentina. Methods: A retrospective study in a cohort of MS patients from fve Argentinian MS centers was conducted. Regarding the availability of different oDMDs in Argentina, we defne three periods (P1-3): P1: 2012 – 2014; P2: 2015 - 2017 and P3: 2018 - 2020. An analysis was performed comparing between these three periods to assess the tendency for oDMDs use over time. Result: The most frequently prescribed treatment as frst DMD was: interferon beta 1a (40%) in P1, fngolimod (37.3%) in P2 and also fngolimod (35%) in P3. We found an increase in the use of oDMTs as initial treatment over time (P1: 17.7%, P2: 63.9% and P3: 65.0%; Chi-square = 41.9 p <0.01). We also found a tendency to increase the use of oDMTs after a frst switch (P1: 45.5%, P2: 60.1% and P3 78.3%). Multivariate analysis showed that disease evolution (OR=1.06, p=0.04), and year of treatment initiation (OR=1.01 p<0.01) were independently associated with choice of oDMTs. Conclusion: This study identifed an increasing tendency for the use of oDMDs as initial treatment of RMS in relationship with their approval in Argentina. Introduction Multiple sclerosis (MS) is an immune-mediated infammatory demyelinating and neurodegenerative disease of the central nervous system that is a leading cause of disability in young adults (Oh et al., 2018). Current therapy for relapsing-remitting-multiple sclerosis (RRMS) is aimed at reducing infammation and axonal damage with the goals of limiting relapses and preventing disease progression (Thomas and Wakefeld, 2015). Disease-modifying drugs (DMDs) are the cornerstone of treatment for RRMS. The complex physiopathology of MS has led to the development of DMDs that vary substantially in their mechanisms of action as well as in administration methods, dosage, effcacy, safety and tolerability (Derfuss et al., 2020). In 1993 the frst study on interferon beta 1b (IFNβ-1b) was published and it was the frst drug that proved to be effective in reducing disability and the number of relapses (IFN beta Multiple Sclerosis Study Group, 2001). Shortly thereafter, two different formulations of IFNβ-1a, and glatiramer acetate also became available. Since then, the treatment of MS was dominated for 15 years by injectable DMDs. Some limitations of injectable MS treatment include variable adverse effects, neutralizing antibodies development, that contribute to loss of drug effcacy (related to IFNβ), patient inconvenience and poor adherence associated with parenteral * Corresponding author: E-mail address: berenice.silva@gmail.com (B.A. Silva). Contents lists available at ScienceDirect Multiple Sclerosis and Related Disorders journal homepage: www.elsevier.com/locate/msard https://doi.org/10.1016/j.msard.2020.102664 Received 30 October 2020; Accepted 28 November 2020