A Real-World Experience of Azathioprine Versus First-Line Disease-Modifying Therapy in Relapsing-Remitting Multiple Sclerosis-A Prospective Cohort Study

Azathioprine (AZA) has demonstrated efficacy in multiple randomized control trials (RCTs) for Relapsing-Remitting Multiple Sclerosis (RRMS). However, we still need comparative real-world data with other first-line disease-modifying therapies (DMTs). We aimed to assess AZA's effectiveness regarding relapses, disability progression, time to the first relapse, magnetic resonance imaging (MRI) activity, and safety compared with other approved first-line DMTs in an Indian population in a real-world setting. We conducted a single-center prospective study of treatment-naive RRMS patients between 2017 and 2019. We evaluated the effects of AZA and other approved DMTs on clinical and radiological measures. Among 192 eligible patients (F:M ratio 2.84:1), 68 patients (35.4%) were on AZA, 68 patients (35.4%) were on dimethyl fumarate (DMF), 32 patients (16.7%) on interferon (IFN beta-1a), and 16 patients (8.3%) on teriflunomide (TFL). Four treatment groups were comparable: AZA v/s DMF v/s TFL v/s IFN beta-1a. In primary outcomes, there was no significant difference between the groups in terms of change in the Expanded Disability Status Scale (EDSS) score at three months (p-value = 0.169), six months (p-value = 0.303), 12 months (p-value = 0.082), and 24 months (p-value = 0.639), the number of relapses (p-value = 0.229), and time to the first relapse (p-value > 0.05 in all groups). In the secondary outcome, there was no significant difference between the treatment groups on serial MRI parameters used according to "Magnetic Resonance Imaging in Multiple Sclerosis" (MAGNIMS) 2016 criteria (p-value > 0.05). In safety outcomes, leukopenia was significantly more common in the AZA group (p-value = 0.025), flu-like symptoms (p-value = 0.0001), and injection site reactions (p-value = 0.035) were significantly more common in the IFN beta-1a group. Our study suggests AZA is as effective as other approved DMTs and a good alternative as a first-line treatment for multiple sclerosis's clinical and radiological activity in real-world settings on short follow-up. Based on these results, more randomized controlled trials of AZA v/s DMF or other DMTs are needed for more robust outcomes.