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Cost-effectiveness of Fingolimod, Teriflunomide, Dimethyl Fumarate and Intramuscular Interferon Beta-1a in Relapsing-Remitting Multiple Sclerosis
Multiple sclerosis (MS) is a disease of the central nervous system with relapse-remitting multiple sclerosis (RRMS) as the most common prognosis. Prior to the introduction of oral therapies, traditional disease-modifying drugs (DMDs) for MS required long-term self-injection; affecting medication adherence. In the past few years, three new oral DMDs, fingolimod, teriflunomide and dimethyl fumarate, have been approved as first-line therapies in the United States. Given limited health care resources, decision makers should consider the comparative cost-effectiveness of these new oral therapies.
Objective
To compare the cost-effectiveness of fingolimod, teriflunomide, dimethyl fumarate and IM IFN β-1a as first-line therapies in treatment of patients diagnosed with RRMS.
Methods
A Markov model was developed to simulate the disease progression and to evaluate the cost-effectiveness of DMDs from a US societal perspective. The time horizon in the base case was 5 years. Model parameters were obtained from randomized controlled trials, natural history studies of MS, cross-sectional surveys and federal supply schedule. Outcomes included costs, Quality-adjusted Life Years (QALYs), incremental net monetary benefit (INMB) and incremental cost-effectiveness ratio (ICER). The willingness-to-pay (WTP) threshold was assumed to be $150,000 per QALY and the costs were in 2012 US dollars. One-way sensitivity analyses and probabilistic sensitivity analyses were conducted to test the robustness of the model results.
Results
The 5 years’ total costs per patient were estimated at $322,694, $339,457, $324,512 and $298,875 for IM IFN β-1a, fingolimod, teriflunomide, and dimethyl fumarate, respectively. The accumulated QALYs associated with each drug were 3.34, 3.69, 3.68 and 3.72, respectively. As a result, Dimethyl fumarate dominated all other therapies over the range of WTPs from $0 to $180,000. Compared with IM IFN β-1a, at the WTP of $150,000, INMBs were estimated at $36,146, $68,486, and $80,970 for fingolimod, teriflunomide, and dimethyl fumarate, respectively. Compared with IM IFN β-1a, ICERs were $47,523 and $5,218 for fingolimod and teriflunomide, respectively, and the ICER of fingolimod versus teriflunomide was $3,451,748. One-way sensitivity analysis demonstrated that model results were sensitive to acquisition costs of DMDs and to the time horizon, but in most scenarios, cost-effectiveness rankings remained stable. Probabilistic sensitivity analysis showed that for more than 90% of the simulations, dimethyl fumarate was the optimal therapy across all willingness-to-pay values.
Conclusion:
The three new oral therapies were favored in the cost-effectiveness analysis. Of the four disease-modifying drugs, dimethyl fumarate was a dominant therapy to manage remitting-relapsing multiple sclerosis. Apart from dimethyl fumarate, teriflunomide was the most cost effective therapy compared with IM IFN β-1a with an incremental cost effectiveness ratio of $5,218.