Cost analysis of biologic drugs in rheumatoid arthritis first line treatment after methotrexate failure according to patients' body weight.

Objective: The objective was to assess the influence of patients' weight in the cost of rheumatoid arthritis treatment with biologic drugs used in first line after non-adequate response to methotrexate.
Patients and Method: Pharmaceutical and administration costs were calculated in two scenarios: non-optimization and optimization of intravenous (IV) vials. The retrospective analysis of 66 patients from a Spanish 1,000 beds-hospital Rheumatology Clinic Service was used to obtain posology and weight data. The study time horizon was two years. Costs were expressed in 2013 euros.
Results: For an average 69kg-weighted patient the lowest cost corresponded to abatacept subcutaneous (SC ABA) (€21,028.09) in the scenario without IV vials optimization and infliximab (IFX) (€20,779.29) with optimization. Considering patients' weight in the scenario without IV vials optimization infliximab (IFX) was the least expensive drug in patients ranged 45-49kg, IV ABA in 50-59kg and SC ABA in patients over 60kg. With IV vials optimization IFX was the least expensive drug in patients under 69kg and SC ABA over 70kg.
Conclusions: Assuming comparable effectiveness of biological drugs, patient's weight is a variable to consider, potentials savings could reach €20,000 in two years.
(Copyright © 2015 Elsevier España, S.L.U. and Sociedad Española de Reumatología y Colegio Mexicano de Reumatología. All rights reserved.)