Effects of low dose methotrexate on relapsing-remitting multiple sclerosis in comparison to Interferon β-1α: A randomized controlled trial

BACKGROUND Methotrexate, a toxic antimetabolite that limits cellular reproduction by acting as an antagonist to folic acid, has been used to control autoimmune disease with different results. The aim of this study was to evaluate the effectiveness of low dose Methotrexate in the relapsing-remitting multiple sclerosis (RRMS). METHODS Eighty patients with definite RRMS aged 15 to 55 years were randomly allocated to receive a 12-month treatment course of either oral Methotrexate (7.5 mg/week) or intramuscular Interferon β-1α (30 μg/week). Response to treatment was assessed at 12 months after start of therapy. RESULTS The results of the study demonstrated significant reduction in relapse rate in both groups (p < 0.01). In 40 patients treated by Methotrexate, the mean value (SD) of relapse rate decreased from 1.75 (0.74) to 0.97 (0.83) (p < 0.01). Correspondingly, the mean value (SD) of relapse rate in patients treated by Interferon β-1α decreased from 1.52 (0.59) to 0.57 (0.78) (p < 0.01). Decrease of relapse rate in Interferon β-1α group was more than that in the other group (p = 0.06). CONCLUSIONS This study suggests that although treatment with Methotrexate may significantly reduce relapse rate and slow progression of disease in patients with RRMS, its efficacy is less than Interferon β-1α and it may be better used as add-on therapy.