Cost-Effectiveness and Efficacy of Natalizumab versus Fingolimod

Minneapolis—Multiple sclerosis (MS) is a chronic, disabling disease of the central nervous system. It affects approximately 400,000 patients in the United States. The most commonly diagnosed category of MS is relapsing-remitting multiple sclerosis (RRMS); patients with RRMS experience alternating episodes of neurologic deterioration and stability without disease progression. Costs associated with treating relapses vary according to the severity of the relapse; they range from $329 (2010 dollars) to $17,420 per episode. Of currently available disease-modifying therapies, natalizumab has the highest efficacy and has been shown to be cost-effective in previous studies. Newer agents for the treatment of MS, including the first oral agent, fingolimod, have not been studied extensively for cost-effectiveness and efficacy. Researchers recently designed a study to assess the cost-effectiveness of natalizumab compared with fingolimod in patients with RRMS. They presented study results at a poster session at the AMCP meeting in a poster titled Cost-Effectiveness of Two Disease-Modifying Therapies for Treatment of Multiple Sclerosis. The primary outcome of the study was the incremental cost per relapse avoided, calculated as the difference between natalizumab and fingolimod in total 2-year cost of therapy divided by the difference between natalizumab and fingolimod in number of relapses avoided over 2 years. The researchers developed a decision-analytic model to estimate the incremental cost per MS relapse avoided of 300 mg natalizumab administered intravenously (IV) once every 4 weeks compared with 0.5 mg fingolimod taken once daily from the perspective of a US managed care payer over a static 2-year time horizon. The cost of a relapse was divided into 3 categories: (1) relapse requiring low-intensity medical management (physician office visit or symptom management with medications; $329); (2) relapse requiring medium-intensity medical management (emergency department visit, observational unit, or acute treatments such as IV medications in either an outpatient or home setting; $2500); or (3) relapse requiring high-intensity medical management (hospitalization and subsequent care; $17,420). The model assumed 40% of patients would require low-intensity care, 40% would require medium-intensity care, and 20% would require high-intensity care. The weighted cost of managing an MS relapse was estimated as $4606. The cost of treating relapses per patient was calculated as the number of relapses per patient that could be anticipated to occur during 2 years of therapy, multiplied by the weighted average cost of managing an MS relapse. Based on average cost-effectiveness ratio, the total 2-year cost per patient was $86,461 for natalizumab and $98,748 for fingolimod; the higher cost of fingolimod was driven primarily by the higher drug acquisition cost, the researchers noted. The number of relapses avoided per patient over 2 years was 0.74 for natalizumab and 0.59 for fingolimod. The cost per relapse avoided was $117,164 for natalizumab and $168,754 for fingolimod. Analysis based on incremental cost-effectiveness ratio found that natalizumab dominates fingolimod because it is less costly (a difference of $12,287) and more effective (0.15 more relapses avoided) over 2 years. In conclusion, the researchers said, “in the absence of head-to-head comparisons between agents, economic models may be useful tools for US payers facing the challenges of offering the best care for patients under limited financial resources. The results of this model suggest that natalizumab dominates the oral agent fingolimod in terms of incremental cost per MS relapse avoided.… Model results were robust in both one-way and probabilistic sensitivity analyses.” This study was supported by funding from Biogen Idec, Inc, and Elan Pharmaceuticals, Inc.