Clinical follow-up of 304 patients with multiple sclerosis three years after mitoxantrone treatment

The objectives of this study were to assess the benefits of 1) mitoxantrone after three years of follow-up and 2) disease-modifying treatment (DMT) after stopping mitoxantrone. A retrospective analysis was performed on 304 patients with active relapsing- remitting (RR) or progressive multiple sclerosis (PMS) who were treated with mitoxantrone. After mitoxantrone therapy, some patients received DMT (interferon-beta or glatiramer acetate) while others did not. The disease course of the two groups was evaluated by the Expanded Disability Status Scale (EDSS) before and after mitoxantrone and then every year for three years. The mean EDSS score at starting mitoxantrone and three years after stopping mitoxantrone respectively, were: 3.3 (1.3) and 3.2 (1.7) for the RRMS patients and 5.9 (1.2) and 6.4 (1.4) for the PMS patients. Before starting mitoxantrone, demographic and clinical parameters of predictive disability were not significantly different between patients who received DMT or not. The variation of EDSS between time of stopping mitoxantrone and three years later was significantly different (+0.9 versus +0.3; P=0.03) for patients with RRMS. We found that mitoxantrone treatment induces stable disease up to two years after discontinuation of mitoxantrone therapy. In the third year, patients without DMT deteriorated.