Monitoring the use of disease-modifying drugs in multiple sclerosis

Background: Current treatment of multiple sclerosis (MS) with disease-modifying drugs (DMDs) includes interferon- (IFN-), glatiramer acetate (GA), and immunosuppressive drugs (e.g., mitoxantrone-MIT, azathioprine-AZA, cyclophosphamide-CY). Knowledge on effectiveness in clinical practice of each DMD, optimal pattern of use (especially, when to start drug therapy) require further investigation. Objectives: To identify criteria for choice of DMDs in MS and to evaluate their comparative effectiveness in clinical practice. Methods: A database of DMDs prescribed to MS pts of an Italian region (4,000,000 inhabitants) provided the following information: patient history, disease characteristics (MS course, disability degree in terms of EDSS, relapses, MRI results), drug therapies (drugs, doses, switches, side effects). Data from May 2006 to December 2007 were collected and the relationship between prescribed drugs and diagnostic parameters was analysed by non-adjusted odds ratio (OR, CI 95%). Results: Data on 934 pts (71% females) were collected. IFN- was prescribed in 73% of cases, followed by GA (12%), by AZA (8%) and by MIT (6%). Other immunosuppressive agents were prescribed only in 1% of cases. IFN-1a represented the most frequent drug choice (67%) in the relapsing remitting pts, whereas in the progressive forms IFN-1b (27%), MIT (25%), and AZA (20%) were significantly preferred to IFN-1a once a week. In pts with high disability (EDSS 3), DMDs with higher frequency of administration (3 times a week, each other day, daily) were significantly preferred to IFN-1a once a week. Conclusions: IFN-1a and GA were preferred in pts with stable and moderate MS, whereas IFN-1b and immunosuppressive agents were especially used in those experienced worsening of the disease. This tool may allow to obtain more solid information on MS therapies and to produce evidence-based recommendations.