Research Article Comparable Efficacy and Safety of Teriflunomide versus Dimethyl Fumarate for the Treatment of Relapsing-Remitting Multiple Sclerosis Nasim Nehzat , 1,2 Omid Mirmosayyeb , 1,2,3 Mahdi Barzegar , 1,3 Reza Vosoughi , 4 Erfane Fazeli , 1 and Vahid Shaygannejad 1,3 1 Isfahan Neurosciences Research Center, Isfahan University of Medical Sciences, Isfahan, Iran 2 Universal Council of Epidemiology (UCE), Universal Scientific Education and Research Network (USERN), Tehran University of Medical Sciences, Tehran, Iran 3 Department of Neurology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran 4 University of Toronto, St. Michael’s Hospital Multiple Sclerosis Clinic, Toronto, Ontario, Canada Correspondence should be addressed to Vahid Shaygannejad; v.shaygannejad@gmail.com Received 2 January 2021; Revised 26 June 2021; Accepted 8 July 2021; Published 15 July 2021 Academic Editor: Jeff Bronstein Copyright © 2021 Nasim Nehzat et al. is is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Background. e aim of this observational study is to investigate the efficacy and safety of two approved oral disease-modifying therapies (DMTs) in patients with remitting-relapsing multiple sclerosis (RRMS): dimethyl fumarate (DMF) vs. teriflunomide (TRF). Methods. A total of 159 RRMS patients (82 on TRF and 77 on DMF) were included. e expanded disability status scale (EDSS), confirmed disability improvement (CDI), confirmed disability progression (CDP), and annualized relapse rate (ARR) were evaluated for the two-year period prior to enrollment in our study. e drug-associated adverse effects (AEs) were recorded. We conducted propensity matching score to compare the efficacy between TRF and DMF. Results. After matching for the confounders, TRF- and DMF-treated groups were not different in terms of EDSS (P value � 0.54), CDI (P value � 0.80), CDP (P value � 0.39), and ARR (P value >0.05). TRF discontinuation occurred in 2 patients (2.43%) due to mediastinitis and liver dysfunction, while a patient (1.29%) discontinued DMF due to depression. Incidence rate of AEs in the TRF-treated group was 81.4%: hair thinning (hair loss) (62.9%), nail loss (20.9%), and elevated aminotransferase (14.8%) were the most common AEs; in DMF-treated patients, AEs were 88.2% with predominance of flushing (73.2%), pruritus (16.9%), and abdominal pain (16.9%). Conclusion. Based on our findings, DMF is as efficacious and safe as TRF for the treatment of RRMS in our Iranian study population. Multicentric studies need to corroborate these findings in other populations. 1. Introduction Over the past 20 years, the outcome of patients with multiple sclerosis (MS) has significantly improved with earlier di- agnosis by magnetic resonance imaging (MRI) and earlier administration of disease-modifying therapies (DMTs) [1]. DMTs consist of treatments targeting the immune system to reduce autoimmune damage to the central nervous system and slow down the natural history of MS [2, 3]. Despite all of the advantages of DMTs, they may cause adverse events (AEs) with different severities leading to nonadherence, decreased quality of life, or treatment dis- continuation [4–6]. is has been more problematic in platform agents like Interferons. An 8-year study of Inter- feron-Beta use in 394 cases with remitting-relapsing MS (RRMS) or secondary-progressive MS (SPMS) patients revealed 14% of treatment discontinuation due to AEs in- cluding flu-like syndrome, injection-site reaction, depres- sion, and fatigue [7]. Another 5-year study on 122 Interferon-Beta-treated RRMS patients reported 23% treatment discontinuation due to either clinical AEs such as local injection-site reaction and flu-like syndrome or Hindawi Neurology Research International Volume 2021, Article ID 6679197, 8 pages https://doi.org/10.1155/2021/6679197