Comparing Prednisone and Methotrexate to Off-label Biologic Infliximab for Management of Ocular Uveitis: A Cost-minimization Analysis

Abstract

Background: Approximately 3.75% of cases of blindness in the United States are caused by uveitis. Incurred clinical costs and lost productivity related to vision loss in these cases totals $3.58 billion annually. Objective: To evaluate whether infliximab, a modern off-label biologic, is cost-effective for treating posterior uveitis and panuveitis compared to current standards of care, methotrexate and prednisone. Methods: A cost-effectiveness analysis using a Markov model to simulate a patient cohort with posterior uveitis or panuveitis. The model followed patients’ therapy from the onset of posterior uveitis or panuveitis using the U.S. societal perspective. The lifetime model simulated health states that could lead to successful reversal of uveitis with standard or intensified treatment with prednisone, methotrexate, or infliximab. Probabilities, health utilities, and costs were included in the model based on findings from the literature. We conducted univariate sensitivity analyses and a Bayesian multivariate probablistic sensitivity analysis to estimate uncertainty in results. Outcomes were measured in terms of costs ($US, 2010) and effects (qualityadjusted life years; QALYs) discounted at 3% per year were estimated for each simulated treatment. An incremental cost-effectiveness ratio (ICER) for pairwise results was interpretted assuming a predetermined willingness-to-pay threshold of $100,000/QALY. Results: Average lifetime costs and QALYs for each drug were ($306.95; 15.80 QALYs) for prednisone, methotrexate ($36,232.24; 16.21 QALYs), and inflixmab ($74,762.63; 15.04 QALYs). Methotrexate was on average compared to prednisone, with an ICER of $86,901.16/QALY. Prednisone and methotrexate dominated infliximab. Sensitivity analyses suggested that the model was most sensitive to the utility for successful recovery from uveitis. The probabilistic sensitivity analysis returned results similar to the base case. Conclusion: This cost-effectiveness analysis suggests that despite advances in the use of biologics for treating sight-threatening posterior uveitis and panuveitis, infliximab had lower effectiveness and higher costs compared to both prednisone and methotrexate. As compared to prednisone, methotrexate was associated with increased costs and QALYs and was found to be a good value. Clinical trials of infliximab in the uveitis population are needed to reduce the uncertain estimates of inflixmab treatment success and the drug’s cost-effectiveness.