OBJECTIVES: To assess the cost-effectiveness of Rebif compared to its comparators in the German health care setting in 2008. METHODS: A decision analysis model was used to estimate the cost-effectiveness of Rebif in patients with relapsing-remitting multiple sclerosis (RRMS). The analysis was based on a comparison of treatment with Rebif (44 mcg tiw) versus all other existing disease modifying drug (DMD) treatments from a societal perspective: Avonex (30 mcg qw), Betaferon (8 MIU qod), Copaxone (20 mg qd). Data sources used included published literature, clinical trials, official German price/tariff lists and national population statistics. The time horizon of the model was four years, which is the maximum follow-up of patients in published clinical trials with interferons.RESULTS: The cost-effectiveness expressed in cost per relapse avoided is €51,250 for Rebif, which compares favourably with the other comparators. The cost per relapse avoided is €133,770 for Avonex, €71,416 for Copaxone and €54,475 for Betaferon, respectively. When cost of disease progression is excluded, the cost per relapse avoided remains favourable for Rebif (€ 54,292) compared with the other drugs (Avonex €143,186, Copaxone €72,809, Betaferon €56,816). Sensitivity analyses varying the discount rate, frequency of type of relapse, cost of relapse, cost of disease progression and non-compliance have a minor impact on the study outcomes.CONCLUSIONS: This study provides evidence on the cost-effectiveness of first-line treatment options for multiple sclerosis in the German setting. In particular, we found that the cost-effectiveness associated with Rebif 44 was favourable compared to other DMDs, providing additional value to payers.