OBJECTIVES: To evaluate the impact of the introduction of Cladribine Tablets in the long term costs of several therapeutic sequences used for the treatment of relapsing-remitting multiple sclerosis in Portugal.

METHODS: An Excel based model was developed to permit the comparison for a single patient of the cost of alternative sequences of treatment, over a 1 to 6 year horizon. Time on treatment for each therapy was determined assuming switch at time of relapse. Data on probability of relapse over time was obtained from published long-term studies following RCTs, namely, FREEDOMS and TRANSFORMS for Fingolimod, ENCORE for DMF, and CLARITY and CLARITY EXT for Cladribine Tablets. Solely drug purchasing costs were included and these were obtained from national official sources. Initial treatments could occur with Cladribine tablets, Fingolimod or DMF, while second line could be done with Fingolimod or Natalizumab (as normal in Portugal). For studies with data shorter than 6 years, final observation was carried forward to year 6.

RESULTS: When all treatment options are compared initial treatment with DMF followed by Natalizumab seems the least expensive option in the short to mid-term (2 to 4 years), however when treatment horizon is expanded up to 6 years, Cladribine followed by Natalizumab becomes a better option (79.676 € vs 82.847 € for DMF-Natalizumab). Regarding Fingolimod, in the first 3 years Fingolimod is cheaper than Cladribine, however beyond the 3rd year Cladribine followed by either Natalizumab or Fingolimod is always cost-saving when compared with Fingolimod followed by Natalizumab (67.270 € for Cladribine-Natalizumab vs 73.810 € for Fingolimod-Natalizumab, over 4 years), with the gap between the costs of the two sequences increasing over time.

CONCLUSIONS: Used according with its label and over a 4 to 6 years horizon, Cladribine tablets can be the best financial option for the treatment of patients with multiple sclerosis in Portugal.