HEALTH ECONOMIC EVALUATION OF DISEASE MODIFYING MEDICINES USED FOR MULTIPLE SCLEROSIS

Purpose: Multiple sclerosis (MS) is one of the most common causes of disability in young adults. Several disease-modifying therapies (DMT) are available for the treatment of MS, but the cost-effectiveness of the different treatments has not been investigated in a Norwegian setting. To ensure the most appropriate MS management, it is important to assess cost-effectiveness of disease modifying medicines used for MS.

Method: We developed a probabilistic decision model to assess the cost-effectiveness of thirteen different DMT used for MS. The model simulates the natural history of MS using the state transition methodology. Health states were defined according to the Kurtzke EDSS (0-10). During one model cycle, patients could remain in the current health state, progress to the next more severe state, transition to a secondary-progressive health state, or die. Patients with an EDDS scale of five or lower could also improve to a less severe state, and experience relapse. Complications were also included in the model. Transitional probabilities were derived from published sources and clinical experts’ opinions. Efficacy estimates for annual relapse and disability progression were based on the network meta-analyses of published RCTs identified by a systematic literature search. Quality of life data were extracted from published studies based on a systematic literature search. Treatment costs were estimated based on official Norwegian unit prices. All costs and health benefits were discounted at a rate of 4% per annum. Sensitivity analysis was performed by means of Monte Carlo simulation.

Result: Alemtuzumab was more effective and less costly than the other strategies. A scenario analysis that excluded alemtuzumab (the dominant strategy) showed that interferon beta-1b (Extavia), peg-interferon beta-1a and natalizumab could be cost-effective depending on the willingness-to-pay (WTP) threshold. Assuming a WTP below EUR107,000 per QALY gained, Extavia was approximately 40% likely to be the most cost-effective treatment, followed by peg-interferon beta-1a (approximately 30% likely). However, more research on efficacy and epidemiologic input parameters would have the greatest impact on reducing decision uncertainty.

Conclusion: Change in clinical practice based on the results of cost-effectiveness analysis has a substantial potential to reduce costs associated with MS treatment.