Study Examines Cost-Effectiveness of Interferon for MS

Boston—Clinical data from the EVIDENCE [Evidence of Interferon Dose-Response: European North American Comparative Efficacy] study found that the cost-effectiveness of subcutaneous interferon (IFN) ß-1a 44 mcg given 3 times weekly was favorable compared with intramuscular IFN ß-1a 30 mcg given once weekly for relapsing forms of multiple sclerosis (MS). The researchers presented the study’s results at the AMCP meeting during a poster session titled A Cost-Effective Evaluation of Subcutaneous and Intramuscular Interferon Beta-1a in Multiple Sclerosis Using Data from Comparative Study EVIDENCE.

MS is a chronic immune-mediated disease of the central nervous system, resulting in a wide range of symptoms, including mobility problems, visual impairment, and cognitive dysfunction. Relapsing forms of MS are characterized by the occurrence of clinical attacks, which are episodes of subacute worsening of neurologic symptoms. Currently, there is no cure for this disease.

For the study, the researchers used health and economic modeling techniques to quantify and compare the clinical and economic outcomes associated with the use of IFN ß-1a subcutaneously versus IFN ß-1a intramuscularly over 2 years of treatment of relapsing forms of MS from a US healthcare payer perspective. A decision analytic model was constructed using a 2-year time horizon. The model was populated with IMS LifeLink Plus prevalence and treatment data. It was also populated with disease-modifying drug (DMD) efficacy data that were calculated from level 1 data obtained from the EVIDENCE study. The model used the IFN ß-1a 44 mcg subcutaneously 3 times weekly dose regimen since that is the most commonly prescribed dosage. The rate of relapse for untreated MS was obtained from the placebo arms of the pivotal clinical DMD trials. Annualized relapse rate data from the 16-month EVIDENCE results were extrapolated for the 2-year model: 1.08 relapses over 2 years with IFN ß-1a 44 mcg and 1.3 relapses over 2 years with IFN ß-1a 30 mcg.

Using a hypothetical health plan with 1 million members, the model estimated that 911 patients with MS would be treated with DMDs. A weighted relapse rate was 2.15 over 2 years for untreated MS patients. Over 2 years, more relapses were avoided with IFN ß-1a 44 mcg compared with IFN ß-1a 30 mcg (979 vs 778, respectively). In terms of the average cost-effectiveness (cost per relapse avoided) of both treatment regimens, IFN ß-1a 44 mcg was lower compared with IFN ß-1a 30 mcg ($123,854 vs $155,610, respectively). Furthermore, sensitivity analysis around model input values demonstrated that the model was robust and that the average cost-effectiveness of IFN ß-1a 44 mcg was consistently more favorable than IFN ß-1a 30 mcg.

“Assessments of cost-effectiveness may facilitate decision-making when selecting treatments for relapsing MS,” the researchers concluded.

EVIDENCE was a head-to-head, assessor-blinded, randomized, multicenter trial that compared the efficacy and safety of 2 IFN ß therapies for the treatment of relapsing forms of MS. Patients were randomized to receive IFN ß-1a 44 mcg subcutaneously 3 times weekly (n=339) or IFN ß-1a 30 mcg intramuscularly once weekly (n=338) for an average of 16 months. The findings showed that significantly more patients receiving IFN ß-1a 44 mcg achieved the primary end point of
remaining relapse-free at 24 weeks compared with patients receiving IFN ß-1a 30 mcg (75% vs 63%, respectively; P<.001).—Eileen Koutnik-Fotopoulos

This study was supported by EMD Serono.