Injectable Disease Modifying Agents in Multiple Sclerosis: Pattern of Medication Use and Clinical Effectiveness.

The objective of this study was to assess long-term use, adherence and efficacy of injectable disease modifying agents (DMAs). Multiple Sclerosis (MS) patients diagnosed during 2002-2010 with early treatment start and at least one year in first choice medication were included in a large university district in Finland. Annualized relapse rates (ARR) during each treatment period were studied, and number of switches by medication evaluated. Use of health care facilities during 2002-2010 was assessed. In the study were included 113 MS patients; 15 (13%) switched medication. The mean duration of treatment period (128) was 3.8 years. In 77% (98/128) the treatment continued with the first DMA for (mean) 3.8 years, in 19% (25/128) with the second for 3.5 years and in 4% (5/128) with the third for 4.8 years. Mean ARR was 0.26, with 54% (69/128) of the periods relapse free. Mean ARR during the treatment periods with product switch was 0.41 before, and 0.28 after the switch, showing a trend towards better efficacy with the second DMA. The usage of health care resources remained within the guidelines. Long-term adherence to first choice DMA was observed, and a switch of product within the DMAs showed continuous adherence and efficacy. The efforts to seek a clinically effective and well tolerated agent within the first-line DMAs is warranted, leading to continued adherence and increased clinical effectiveness.