Cost-effectiveness of the addition of rituximab to CHOP chemotherapy in first-line treatment for diffuse large B-cell lymphoma in a population-based observational cohort in British Columbia, Canada.

BACKGROUND: Diffuse large B-cell lymphoma (DLBCL) has primarily been treated with cyclophosphamide, doxorubicin, vincristine, and predisone (CHOP) chemotherapy since the 1970s. Recently, the addition of rituximab to CHOP (CHOP-R) has been found to improve survival and trial-based results have suggested that it is a cost-effective alternative to CHOP.

OBJECTIVES: The objective in this study was to evaluate the cost-effectiveness of CHOP-R relative to CHOP in first-line treatment of DLBCL in a population-based setting in British Columbia, Canada.

METHODS: We created a patient-level simulation model describing potential pathways for DLBCL patients initiating treatment with either CHOP or CHOP-R. Model parameters were populated with statistical analyses of individual-level treatment and effectiveness data and published cost estimates. All results were stratified by age at treatment initiation (<60 years vs. ≥60 years). The base-case scenario was based on a 15-year time horizon and a 3% discount rate. Probabilistic sensitivity analysis was performed. All costs are reported as 2006 $CDN.

RESULTS: For the base-case scenario, incremental cost-effectiveness ratios (ICERs) for younger individuals ranged from $11,965 per disease-free life-year gained to $19,144 per quality-adjusted life-year gained. For older individuals, estimated ICERs for all health outcomes were below $10,000 per unit outcome gained for a 15-year time horizon.

CONCLUSIONS: Using population-based data, CHOP-R was found to be a cost-effective alternative to CHOP, particularly for individuals aged 60 years and older. Results from this Canadian observational data source were consistent with international clinical trial-based studies. The use of CHOP-R as a first-line treatment for DLBCL is recommended, with respect to both clinical and cost-effectiveness.