STANFORD, CaliforniaThe cost-effectiveness of rituximab(Drug information on rituximab) (Rituxan) combined with CHOP chemotherapy (cyclophosphamide [Cytoxan, Neosar], doxorubicin(Drug information on doxorubicin) HCl, vincristine [Oncovin], prednisone(Drug information on prednisone)) in the treatment of patients with diffuse large B-cell lymphoma compares favorably to other oncology therapies in this setting, according to a study presented at the 43rd Annual Meeting of the American Society of Hematology.
Study ObjectiveThe objective of the study was to estimate the cost-effectiveness of rituximab combined with CHOP (R-CHOP). The authors analyzed data from the Groupe d’Etude des Lymphomas de l’Adulte (GELA) study (see "R-CHOP Benefits Increase Over Time for Aggressive Large B-Cell Lymphomas in Elderly"), which compared the classic CHOP regimen with R-CHOP. The open-label trial enrolled 400 previously treated elderly patients (age range: 60-80 years) who were randomized between R-CHOP and CHOP (see Figure 1).
An interim analysis was conducted after at least 200 patients had been recruited, and 100 of those were followed for at least 1 year. "To assess the cost-effectiveness of R-CHOP vs CHOP, we estimated years of life gained, costs during treatment, and costs of years of life gained over the trial period," said coauthors John C. Hornberger, MD, Internal Medicine, Stanford University, and Acumen, LLC, and Jennie Best, also of Acumen.
The Study Model
The investigators developed a 10-year model because approximately 30% of the age group in the cohort were expected to survive for at least 10 years. Costs and survival were discounted at 3% and then used to calculate the cost-effectiveness ratio (costs per discounted life-year saved).
To estimate expected survival patterns for 10 years of follow-up, and thus project years of life gained, the investigators stratified trial-based data to an age-adjusted ratio based on the International Prognostic Index (IPI), and matched these data to the published evidence on long-term survival of diffuse large B-cell lymphoma patients.