Cost-Effectiveness Modeling in Multiple Sclerosis: Playing Around with Non-Healthcare Costs?

Abstract

Multiple sclerosis (MS) is a chronic disabling neurological disorder that affects more than two million people worldwide [1]. Accounting for more than half of the total population diagnosed with MS in the world, Europe is considered a high-prevalence region [1]. Patients with MS experience a wide range of signs and symptoms [2], which impair their capacity to perform day-to-day activities and thus quality of life [2, 3]. The onset of MS at an early age implies a substantial burden in terms of both healthcare and societal costs [2]. The drugs currently used to treat MS aim to alleviate symptoms, delay disease progression and, ultimately, disability. Steroidal anti-inflammatory drugs are traditionally used to inhibit the inflammatory process of MS, then various types of drugs can be used to alleviate the different symptoms (e.g., visual, motor, cognitive). However, the most important therapeutic group is the disease-modifying drugs (DMDs); drugs designed to delay the progression and the development of long-term disability. DMD prescription is still mainly restricted to patients with relapsing-remitting MS (RRMS), although there are some DMDs indicated for specific conditions of secondary progressive MS [4]. The two beta interferons (IFNb-1a and 1b) and glatiramer acetate (GA) have been the first-line DMDs for years. Indicated in patients with at least two relapses in the previous 2 years, they are all injectable (IFN b-1b and GA subcutaneous, IFN b-1a subcutaneous or intramuscular) [4]. More recently, other DMDs have been approved as second-line treatments: (1) natalizumab, a monoclonal antibody injected intravenously; (2) alemtuzumab, another monoclonal antibody for intravenous injection (initially marketed as an anticancer drug) that has recently proved to benefit MS patients, and (3) fingolimod, an oral drug that prevents lymphocyte migration to the central nervous system. Finally, the European Medicines Agency has very recently approved two oral first-line DMDs with different mechanisms of action [5]: teriflunomide and dimethyl fumarate. The pharmaceutical costs of MS have risen steeply over the previous few years, mainly owing to the introduction of new DMDs. Although medical evidence on the most dated DMDs is quite well established, the economic literature on these drugs is still controversial [6–9], casting doubts on their cost effectiveness. In this commentary, we assess the potential contribution of cost-effectiveness analyses to pricing and reimbursement decisions in Europe. In particular, we analyze the credibility of the major assumptions contained within the analyses.