Cost-effectiveness of the long-term use of temozolomide for treating newly diagnosed glioblastoma in Germany

Concomitant radiochemotherapy followed by six cycles of temozolomide (= short term) is considered as standard therapy for adults with newly diagnosed glioblastoma. In contrast, open-end administration of temozolomide until progression (= long-term) is proposed by some authors as a viable alternative. We aimed to determine the cost-effectiveness of long-term temozolomide therapy for patients newly diagnosed with glioblastoma compared to standard therapy. A Markov model was constructed to compare medical costs and clinical outcomes for both therapy types over a time horizon of 60 months. Transition probabilities for standard therapy were calculated from randomized controlled trial data by Stupp et al. The data for long-term temozolomide therapy was collected by matching a cohort treated in the Department of Neurosurgery at Jena University Hospital. Health utilities were obtained from a previous cost utility study. The cost perspective was based on health insurance. The base case analysis showed a median overall survival of 17.1 months and a median progression-free survival of 7.4 months for patients in the long-term temozolomide therapy arm. The cost-effectiveness analysis using all base case parameters in a time-dependent Markov model resulted in an incremental effectiveness of 0.022 quality-adjusted life-years (QALYs). The incremental cost-effectiveness ratio (ICER) was €351,909/QALY. Sensitivity analyses showed that parameters with the most influence on ICER were the health state utility of progression in both therapy arms. Although open-ended temozolomide therapy is very expensive, the ICER of this therapy is comparable to that of the standard temozolomide therapy for patients newly diagnosed with glioblastoma.