Abstract

The effects of combined treatment with cyclophosphamide (CTX) and interferon-β (IFN-β) are described in selected patients with “rapidly transitional” multiple sclerosis. This form of multiple sclerosis is extremely active with very frequent and severe attacks which produce a dramatic increase on the expanded disability status scale (EDSS). Ten patients with rapidly transitional multiple sclerosis were previously treated with interferon-β, but none benefited by this treatment. Monthly treatment with intravenous CTX, from 500 mg/m² to 1500 mg/m² to obtain a chronic lymphocytopenia (600/mm³ to 900/mm³) produced a marked and significant reduction in the number of relapses (p<0.0001), disability previously accumulated (p<0.0001), and a reduction of T2 MRI burden of lesion. This particular group of patients benefited by combining cyclophosphamide and IFN-β. The possibility is considered of carrying out further studies to test the efficacy of the association between the two drugs for patients who are not responsive to IFN-β or other active disease modifying therapies.