New One-Year Pharmacoeconomic Study Shows AVONEX(R) is Cost-Effective Relative to Other Interferon Therapies for Multiple Sclerosis

Biogen Idec Inc. (NASDAQ: BIIB) announced today that one-year data presented at the Academy of Managed Care Pharmacy’s (AMCP) 2007 Annual Meeting show that AVONEX® (Interferon beta-1a) is a cost-effective therapy in multiple sclerosis (MS) when compared to other interferon beta treatments. Using a comprehensive analysis of medical and pharmacy costs, the results of the research concluded that patients treated with AVONEX, the most prescribed MS therapy worldwide, have the lowest total one-year cost to a health plan when compared to other interferon beta treatments. Researchers analyzed 10,622 patients over one year to assess how demographic, administrative and clinical variables affect MS costs and utilization patterns and to examine the economic impact of treating MS. The independent data contained in Multiple Sclerosis Benchmarks™1, the retrospective, claims-based, observational study, showed that patients treated with AVONEX had the lowest average one-year cost compared to patients receiving other interferon beta treatments. It has been estimated that the total annual economic burden of MS in the United States exceeds $6.8 billion with a lifetime cost of $2.2 million per patient.2 "MS is a disease that can have an impact beyond its debilitating effect on patients,” said Michael Pollock, Vice President, Global Health Economics, Biogen Idec. "Cost-effectiveness is an increasingly important factor in treating chronic diseases like MS. This study shows that in addition to its clinical impact, AVONEX can also help to substantially reduce the cost of care for patients living with this disease, when compared to other interferon beta treatments.” The MS Benchmarks analysis showed the total costs over one-year to MS patients on interferon beta therapy were: AVONEX, $19,896.15; Rebif® (Interferon beta-1a) sc, $22,207.85; and Betaseron® (Interferon beta-1b), $21,073.33. In addition, AVONEX patients were more likely to refill their prescriptions (avg.9.6/yr vs. 8.1 and 8.2/yr for other interferon beta therapies) and were less likely to use certain concomitant medications. Over the one-year period, use of disease-modifying therapies (interferon beta and glatiramer acetate) was almost always observed as monotherapy, reflecting little evidence of combination use or switching between products. Additionally, according to data from the Quality Assessment of Multiple Sclerosis Therapy (QUASIMS) study presented at the AMCP Conference, patients do not derive additional clinical benefit from switching among interferon beta therapies. QUASIMS, an open-label, retrospective, observational study conducted in 14 countries, analyzed 7,156 MS patients who had received two years of uninterrupted therapy with interferon beta as initial therapy or follow-up therapy. About AVONEX AVONEX is the most prescribed treatment for relapsing forms of MS worldwide, with more than 130,000 patients on therapy. It was launched in the U.S. in 1996 and later in Europe for the treatment of relapsing forms of MS to slow the progression of disability and reduce relapses. AVONEX is marketed internationally in more than 90 countries. AVONEX was the first treatment approved for patients who have their first clinical MS attack and have a brain MRI scan consistent with MS; this use was approved in Europe in 2002 and in the U.S. in 2003. The most common side effects associated with AVONEX multiple sclerosis treatment are flu-like symptoms, including myalgia, fever, fatigue, headache, chills, nausea, vomiting, pain and asthenia. AVONEX should be used with caution in patients with depression or other mood disorders and in patients with seizure disorders. AVONEX should not be used by pregnant women. Patients with cardiac disease should be closely monitored. Patients should also be monitored for signs of hepatic injury. Routine periodic blood chemistry and hematology tests are recommended during treatment with AVONEX. Rare cases of anaphylaxis have been reported. Please see complete prescribing information available at www.AVONEX.com. About Biogen Idec Biogen Idec creates new standards of care in therapeutic areas with high unmet medical needs. Founded in 1978, Biogen Idec is a global leader in the discovery, development, manufacturing, and commercialization of innovative therapies. Patients in more than 90 countries benefit from Biogen Idec's significant products that address diseases such as lymphoma, multiple sclerosis, and rheumatoid arthritis. For product labeling, press releases and additional information about the company, please visit www.biogenidec.com. # # # 1 "Multiple Sclerosis Benchmarks” is a trademark of Managed Care Measures, LLC. 2 Coyle PK, Hartung HP. Use of interferon beta in multiple sclerosis: rationale for early treatment and evidence for dose-and frequency-dependent effects on clinical response. Multiple Sclerosis. 2002: 8:2-9.