[Newer disease--modifying drugs: glatiramer acetate and mitoxantrone]

Glatiramer acetate(GA) is a synthetic molecule composed of four amino acids: glutamine, lysine, alanine, and tyrosine. These four amino acids are represented in myelin basic protein, which is a suspect antigen involved in the induction of autoimmunity in multiple sclerosis (MS). Subcutaneous GA 20 mg/day showed a reduction of the mean relapse rate and a slower decline of Expanded Disability Status Scale(EDSS) in patients with relapsing-remitting MS(RRMS). In addition, GA is effective in reducing magnetic resonance imaging(MRI) measured activity in patients with RRMS. The drug is generally well tolerated and is not associated with the influenza-like symptoms. Mitoxantrone(MX), a cytotoxic drug exhibiting very potent immunosuppressive properties, has been found effective on relapse rate and progression of disability in patients with worsening RRMS or secondary progressive MS. An induction phase with the monthly intravenous administration of 12 mg/m2 followed by a maintenance phase with 12 mg/m2 every 3 months for 2 years seems the most effective and safe treatment regimen, not exceeding the maximum cumulative dose of 140 mg/m2. Cardiotoxicity, the major long-term toxicity, is clearly dose-dependent and is a strict treatment duration limiting factor.