Cost-effectiveness of injectable disease-modifying therapies for the treatment of relapsing forms of multiple sclerosis in Spain

Objective To compare the cost-effectiveness of injectable disease-modifying therapies (DMTs) for the first-line treatment of relapsing-remitting multiple sclerosis (RRMS) in Spain. Methods A Markov model was developed to estimate the cost-effectiveness of intramuscular interferon beta-1a (IM IFNβ-1a), subcutaneous interferon beta-1a (SC IFNβ-1a), interferon beta-1b (IFNβ-1b) and glatiramer acetate (GA) relative to best supportive care in a hypothetical cohort of 1,000 RRMS patients in Spain. The model was developed from a societal perspective with a time horizon of 30 years. Natural history and clinical trial data were used to model relapse rates and disease progression. Cost and utility data were obtained from a published survey of multiple sclerosis patients in Spain. The primary outcome measure was cost per quality-adjusted life year (QALY) gained. Univariate and probabilistic sensitivity analyses were performed. Results Compared to best supportive care, the base case cost-effectiveness was €168,629 per QALY gained for IM IFNβ-1a, €231,853 per QALY gained for IFNβ-1b, €295,638 per QALY gained for SC IFNβ-1a, and €318,818 per QALY gained for GA. Results were most sensitive to changes in DMT cost, utility values and treatment effect. Conclusions In our cost-effectiveness analysis of first-line injectable DMTs in Spain, we found IM IFNβ-1a to be more cost-effective than SC IFNβ-1a, IFNβ-1b or GA. Sensitivity analyses confirmed the robustness of these results.