Non-specific immunosuppressants in the treatment of multiple sclerosis

Immunosuppressants have been proposed as disease-modifying treatments in multiple sclerosis (MS) for almost 40 years, but only one, mitoxantrone, has recently been approved, whereas β-interferons and glatiramer acetate have been licensed since the mid-90s. Recent therapeutic trials of potent immunosuppressive agents such as Campath-1H, mitoxantrone and cyclophosphamide of MS patients with high relapse rates, rapid accumulation of disability and high degree of MRI activity, have resulted in strong suppression of clinical and MRI inflammatory activity, provided that profound and prolonged lymphopenia was achieved. Clinical experience during the past decades has amply demonstrated that some patients with MS respond to immunosuppressants. The odds ratios of relapsing-remitting MS patients to remain relapse-free after a 2-year period of treatment are similar for Betaseron®, Avonex®, Rebif®, Copaxone®, intravenous immunoglobulins or azathioprine compared to placebo. The risk of cancer induction is not significant for up to 10 years of daily usage of azathioprine. Currently available non-specific immunosuppressants are able to control inflammation and reduce relapses in MS, but cannot prevent neurodegeneration and the progression of irreversible disability; specific tools need to be developed for that purpose.