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Multiple sclerosis (MS) is an inflammatory autoimmune disorder of the central nervous system that primarily afflicts young adults. Approximately 400,000 people in the United States are affected by MS. Although several forms of MS exist, the most common course is known as relapsing-remitting MS (RRMS), which affects about 85% of MS patients. This form of MS is characterized by relapses of neurologic symptoms followed by periods of recovery. Progression of disease can lead to increasingly severe disability. Since the introduction of immunomodulatory biologic agents, such as interferon betas and glatiramer acetate, treatment has helped to change the course of the disease. Under budgetary constraints, health services payers are challenged to differentiate the economic value of these agents for formulary selection and/or placement.The primary objective of this analysis was to evaluate the 2-year cost-effectiveness of 4 disease modifying drugs (DMDs) used as first-line treatment of RRMS: glatiramer acetate, interferon (IFN) Beta-1a IM injection, IFN Beta-1a SC injection, and IFN Beta-1b SC injection.An Excel-based model was developed to compare the relative effectiveness and cost components of relapses, disability progression, and DMDs in the treatment of RRMS over a 2-year time horizon. The relative risk reduction (RRR) method was used to compare reduction in relapse rates and disease progression data from pivotal randomized double-blind placebo-controlled clinical trials of the DMDs. RRRs for relapses and disability progression, respectively, were calculated as the relative difference (treatment vs. placebo) in relapse rates and disease progression rates from placebo-controlled clinical trials. These RRRs were applied to the weighted average rates of relapse and number of disability progression steps seen in the placebo arms of the pivotal studies. The evaluation was conducted from the perspective of a U.S. health care payer (only direct medical costs considered). Medical savings were calculated as costs saved due to relapses avoided and prevention in disability progression steps. In the base case analysis, we assumed 89.4% persistence, a cost per relapse of $4,682, and a cost per disability progression step of $1,788. Monthly cost of therapy was defined as wholesale acquisition cost ($0 contractual discounts and $25 patient copayment assumed in the base case analysis) plus routine monitoring costs as assessed by an expert panel. The primary economic endpoint was cost per relapse avoided. Costs and outcomes occurring in the second year were discounted 3% to bring to 2008 present values. Oneway and multiway probabilistic (Monte Carlo) sensitivity analyses were conducted on key input variables to assess their impact on cost per relapse avoided.Without DMD treatment, patients were predicted to experience 2.55 relapses and 0.44 disability progression steps over a 2-year period (discounted values). The 2-year reductions in clinical relapses for treatment with glatiramer acetate, IFN Beta-1a IM injection, IFN Beta-1a SC injection, and IFN Beta-1b were 0.66, 0.42, 0.74, and 0.70, respectively. The 2-year reductions in disability progression steps for treatment with glatiramer acetate, IFN Beta-1a IM injection, IFN Beta-1a SC injection, and IFN Beta-1b were 0.05, 0.15, 0.12, and 0.11, respectively. In the base case analysis, IFN Beta-1a SC injection, IFN Beta-1b SC injection, and glatiramer acetate had the most favorable costs per relapse avoided ($80,589; $87,061; and $88,310; respectively) and IFN Beta-1a IM injection had the least favorable cost-effectiveness ratio ($141,721 per relapse avoided). Sensitivity analyses showed that these results were robust to changes in key input parameters, such as the number of relapses and disease progression steps in untreated patients, the RRR in clinical relapse and progression rates, the rate of persistence, the average cost of relapse, and the average cost of a disease progression step.This evaluation suggests that IFN Beta-1a SC injection, IFN Beta-1b SC injection, and glatiramer acetate represent the most cost-effective DMDs for the treatment of RRMS, where cost-effectiveness is defined as cost per relapse avoided, assuming that (a) the RRR in relapses and disease progression steps calculated from multiple DMD placebo-controlled clinical trials reflect real differences among DMDs over 2 years; and (b) resource unit costs derived from published sources reflect economic consequences of relapses and disease progression.

Treatment options for the management of rheumatoid arthritis (RA) have expanded from the traditional disease-modifying antirheumatic drugs (DMARDs) to include the biologic DMARDs that inhibit tumor necrosis factoralpha (TNF-a).To assess the medical literature for studies of the economic value of biologic DMARDs, specifically the 3 TNF-a inhibitors (adalimumab, etanercept, and infliximab) used for the management of RA, compared with the traditional DMARDs such as sulfasalazine, antimalarials, penicillamine, gold, methotrexate, azathioprine, leflunomide, and cyclophosphamide.A comprehensive search of the MEDLINE and HealthSTAR databases was conducted to identify cost-efficacy, cost-effectiveness, or cost-utility studies published in the English language (from 1966 through November 2004). The search terms and/or MeSH (medical subject headings) titles were cost-benefit analysis, rheumatoid arthritis, antirheumatic agents, antineoplastic and immunosuppressive agents. Studies were critically reviewed and quality was assessed using the Quality of Health Economic Studies instrument. Most studies evaluated the use of biologics among RA patients resistant to DMARDs. Studies were assessed with regard to comparators evaluated, measures of efficacy, perspectives, model duration, treatment duration, and discount rate.From 180 titles identified, 155 were excluded for the following reasons: 89 because they did not consider the drugs of interest, 15 because the population was not RA, 19 because of having the wrong drugs and population, 22 because they were review articles, and 10 because they were general articles. Twentyfive abstracts were accepted for further review. Of these, 13 abstracts were subsequently selected for full-text review. One of the authors identified a study not indexed in MEDLINE. Ultimately, 2 cost-effectiveness and 6 cost-utility studies were selected for this critical review. One study over 6 months reported that triple therapy with DMARDs (methotrexate-hydroxychloroquine-sulfasalazine) was cost effective for methotrexate-resistant patients, which is consistent with American College of Rheumatology (ACR) guidelines that support the use of triple therapy prior to biologics. The incremental cost-effectiveness ratio (ICER) was $1,500 per patient to achieve an ACR20 response for this triple therapy compared with no second-line agent. Overall, biologic therapies cost considerably more than traditional DMARDs but produced more quality-adjusted life-years (QALYs). Despite differences in design and assumptions, published economic models consistently reported ICERs50,000 dollars per QALY gained for biologics compared with traditional DMARDs, although ICERs of100,000 dollars were reported from sensitivity analyses.Clinical guidelines currently recommend the use of biologics as step therapy after failure of traditional DMARDs. Reported ICERs comparing biologics with traditional DMARDs are within a range that is comparable with other accepted medical interventions. The worth of the additional expenditure will ultimately be judged by formulary and policy decision makers because no maximum cost has been defined. Models can be used to inform decision makers, but they must be interpreted and applied carefully. More research is also needed to differentiate the relative economic value of the various biologic agents by therapeutic indication.