Cost-effectiveness analysis of rituximab with methotrexate, cytarabine and thiotepa for the treatment of patients with primary central nervous system lymphoma

The International Extranodal Lymphoma Study Group-32 (IELSG32) randomized patients with primary central nervous system lymphoma (PCNSL) for induction treatment with methotrexate-cytarabine, methotrexate-cytarabine-rituximab, or methotrexate-cytarabine-thiotepa-rituximab (MATRix) and reported significantly improved complete remission with the MATRix regimen. This study assessed cost-effectiveness among these three induction strategies for PCNSL. A Markov model was developed based on the IELSG32 trial over a 20 year time horizon from the Canadian health care system perspective. Costs for induction, consolidation, inpatient treatment administration, follow-up, adverse events, relapsed disease, and palliative care were included. Methotrexate-cytarabine-rituximab was subject to extended dominance by the other two strategies. The MATRix regimen compared to methotrexate-cytarabine produced 3.05 quality-adjusted life year (QALY) gains at added costs of $75,513, resulting in an incremental cost-effectiveness ratio of $24,758/QALY gained. The MATRix regimen was the optimal strategy in the majority of simulations (98% probability at willingness-to-pay of $50,000/QALY gained) and results appeared robust across sensitivity analyses.