Impact on Medical Cost, Cumulative Survival, and Cost-Effectiveness of Adding Rituximab to First-Line Chemotherapy for Follicular Lymphoma in Elderly Patients: An Observational Cohort Study Based on SEER-Medicare

Rituximab improves survival in follicular lymphoma (FL), but is considerably more expensive than conventional chemotherapy. We estimated the total direct medical costs, cumulative survival, and cost-effectiveness of adding rituximab to first-line chemotherapy for FL, based on a single source of data representing routine practice in the elderly. Using surveillance, epidemiology, and end results (SEER) registry data plus Medicare claims, we identified 1,117 FL patients who received first-line CHOP (cyclophosphamide (C), doxorubicin, vincristine (V), and prednisone (P)) or CVP +/？ rituximab. Multivariate regression was used to estimate adjusted cumulative cost and survival differences between the two groups over four years after beginning treatment. The median age was 73 years (minimum 66 years), 56% had stage III-IV disease, and 67% received rituximab. Adding rituximab to first-line chemotherapy was associated with higher adjusted incremental total cost ($18,695; 95% Confidence Interval (CI) $9,302–$28,643) and longer adjusted cumulative survival (0.18 years; 95% CI 0.10–0.27) over four years of followup. The expected cost-effectiveness was $102,142 (95% CI $34,531–296,337) per life-year gained. In routine clinical practice, adding rituximab to first-line chemotherapy for elderly patients with FL results in higher direct medical costs to Medicare and longer cumulative survival after four years. 1. Introduction Like many countries, the United States is struggling with the rising costs of cancer care [1]. Nowhere is this more apparent than within Medicare, the primary payer of health services for those of age ≥65 years, where the rise in spending on cancer drugs over the past 15 years has been singled out as a leading cause of increased spending overall [2]. Presently, Medicare’s ability to control rising spending on cancer drugs is limited [2], and it is also well known that Medicare does not formally consider cost or cost-effectiveness as a criterion for coverage and reimbursement [1]. Since most new drugs cost considerably more than older drugs [2, 3], and since many are added to rather than substituted for drugs in existing regimens, the net cost impact of new drugs will be determined primarily by the cost of the drug itself, and secondarily by the extent to which those costs are augmented or offset by its clinical benefits. In cancer care, clinical benefits that have cost implications include reducing the rate of disease progression or relapse after first-line therapy and improving survival. It is standard practice to include all of these factors in