Cost-effectiveness of natalizumab versus fingolimod for the treatment of relapsing multiple sclerosis.

Background: With the addition of new agents for the treatment of multiple sclerosis (MS) (e.g., fingolimod), there is a need to evaluate the relative value of newer therapies in terms of cost and effectiveness, given healthcare resource constraints in the United States.

Objective: To assess the cost-effectiveness of natalizumab vs fingolimod in patients with relapsing MS.

Methods: A decision analytic model was developed to estimate the incremental cost per relapse avoided of natalizumab and fingolimod from a US managed care payer perspective. Two-year costs of treating patients with MS included drug acquisition costs, administration and monitoring costs, and costs of treating MS relapses. Effectiveness was measured in terms of MS relapses avoided (data from AFFIRM and FREEDOMS trials). One-way and probabilistic sensitivity analyses were conducted to assess uncertainty.

Results: Mean 2-year estimated treatment costs were $86,461 (natalizumab) and $98,748 (fingolimod). Patients receiving natalizumab had a mean of 0.74 relapses avoided per 2 years vs 0.59 for fingolimod. Natalizumab dominated fingolimod in the incremental cost-effectiveness analysis, as it was less costly and more effective in reducing relapses. One-way sensitivity analysis showed the results of the model were robust to changes in drug acquisition costs, administration costs, and costs of treating MS relapses. Probabilistic sensitivity analysis showed natalizumab was cost-effective 95.1% of the time, at a willingness-to-pay (WTP) threshold of $0 per relapse avoided, increasing to 96.3% of the time at a WTP threshold of $50,000 per relapse avoided.

Limitations: Absence of data from direct head-to-head studies comparing natalizumab and fingolimod, use of relapse rate reduction rather than sustained disability progression as primary model outcome, assumption of 100% adherence to MS treatment, and not capturing adverse event costs in the model.

Conclusions: Natalizumab dominates fingolimod in terms of incremental cost per relapse avoided, as it is less costly and more effective.