Cost-effectiveness of rituximab plus CVP for first-line treatment of advanced indolent lymphoma

Abstract

6583 Background: The addition of rituximab (RTX) to CVP (cyclophosphamide, vincristine, prednisone) in the treatment of advanced follicular lymphoma increases median time to progression by 17 months (15 month v 32 months; p < 0.0001) (Marcus et al, Blood 2005). A societal cost-effectiveness analysis was performed to estimate projected lifetime clinical and economic implications of this treatment. Methods: The cost-effectiveness (CE) of RTX + CVP versus CVP was estimated for a 50 yr old patient. Kaplan-Meier estimates of progression-free and overall survival, up to 4 years, were obtained from the M39021 trial. After 4 years, transition rates from initiation of treatment to progression or death were assumed to be the same in both arms. The clinical and economic implications of relapse and its treatment were included in the model. Incremental costs associated with addition of RTX were estimated using Medicare reimbursement rates and published retail price data. Costs included drug and administration costs, adverse events, treatment of relapses, and end-of-life costs. Utility estimates were derived from the literature and a 3% discount rate was employed. Results: Projected mean overall survival is 1.5 yrs longer for patients assigned to RTX+ CVP versus only CVP (13.7 v 12.2 yrs). The addition of RTX to CVP is estimated to cost an additional $26,439 on average, with an expected gain of 0.85 year of quality-adjusted survival. Over a lifetime, the cost per QALY gained is $31,329. Sensitivity analyses revealed that the variables that most influenced cost-effectiveness were the time horizon (range: $18,800- $31,240) and the unit drug cost of RTX (range: $24,000-$38,000). Conclusion: The model estimates a cost-to-QALY gained ratio that is below that of many treatments used for oncology patients. The use of RTX + CVP for first-line treatment of advanced follicular lymphoma is projected to be cost-effective compared to CVP alone under a range of sensitivity analyses. No significant financial relationships to disclose.