Per-head cost of patients responding to eltrombopag and rituximab in the treatment of primary immune thrombocytopenia in Spain.

Abstract

Background: Splenectomy, thrombopoietin receptor agonists (TPO-RAs) and rituximab are the secondline treatments for steroid-resistant adult primary immune thrombocytopenia (ITP). The last two are becoming the most widely used treatments to avoid splenectomy adverse effects and inconveniences.However, the choice between rituximab and TPO-RAs is unclear. Therefore, the treatment cost may be of particular interest to prioritize the therapy option.Our aim is to determine the cost per patient after 6 months of treatment of rituximab compared to TPO-RA eltrombopag in a European Health Service.Methods: A 26-week decision tree model was developed to assess the cost of treatment response of adult patients with chronic-refractory ITP to eltrombopag and rixutimab from the perspective of the Spanish National Health System. Effectiveness was obtained from the literature, and cost was obtained from the official rates. Costs were expressed in € (2018). Due to the short period of assessment, no discount rate was applied.Results: The average cost per patient after 6 months of treatment was similar for eltrombopag and rituximab, although the first cost was slightly higher. However, the greater response rate of eltrombopag decreases the bleeding costs, resulting in a 29% higher cost with rituximab treatment.Eltrombopag cost was always lower, except in the sensitivity analysis in which the patient received a daily dose of 75 mg of eltrombopag, a scenario where eltrombopag cost is 48€ higher than that of rituximab.Conclusions: The treatment cost of rituximab, including monitoring and bleeding costs, is higher than eltrombopag, favouring the latter over rituximab treatment. BackgroundPrimary immune thrombocytopenia (ITP) is an acquired autoimmune disease characterized by a platelet count less than 100 x 10 9 platelets/litre; this is due to platelet destruction and inadequate production [1,2]. Diagnosis is reached by exclusion of other diseases associated with thrombocytopenia. The annual ITP incidence rate is 3-4/100000 in adults, increasing in older patients [3][4][5]. This condition is classified as newly diagnosed ITP when the evolution is shorter than 3 months 3 from diagnosis, persistent if the duration of disease is 3-12 months and chronic when it lasts for more than 12 months [1]. Although 1/3 of affected persons are asymptomatic and patients with a platelet count over 50 x 10 9 platelets/litre do not require treatment, this long-lasting disease may threaten life due to bleeding caused by thrombocytopenia; it negatively impacts quality of life and imparts a high economic burden on the healthcare system [1,2,6].Classical guidelines recommended corticosteroids as first-line treatment for adult ITP followed by splenectomy as second-line treatment and the use of the anti-CD20 chimeric monoclonal antibody rituximab or a thrombopoietin receptor agonist (TPO-RA) in cases of failure or contraindication [2,7,8].Splenectomy achieves a 60% response after 5 years [9]. However, this treatment produces important adverse effects mainly derive...