First and Only Therapy Approved for This Use

Biogen, Inc. (NASDAQ/BGEN) today announced the U.S. Food and Drug Administration (FDA) has approved AVONEX® (Interferon beta-1a) to include treatment of patients with a first multiple sclerosis (MS) attack if brain MRI scan abnormalities characteristic of MS are shown.

The first sign that a patient may have MS is a single, clinical event. Until now, standard practice has been to treat MS only after a patient experiences at least two clinical events. AVONEX is the first treatment approved for MS patients who have their first clinical MS attack and have a brain MRI scan that suggests MS. This use was approved in Europe in 2002.

“Physicians can now initiate therapy with AVONEX at the first signs and symptoms of MS, rather than waiting until the disease has further progressed and patients have experienced a second attack,” said study investigator R. Philip (Rip) Kinkel, M.D., Director of the Multiple Sclerosis Center at Beth Israel Deaconess Medical Center in Boston, MA. “We are continuing to follow the patients from the CHAMPS study in what is called the CHAMPIONS study to determine if we can actually alter the long-term course of the disease through early initiation of AVONEX therapy.”

The new labeling for AVONEX includes updated safety information based on post-marketing experience. The revisions to the label were to the warnings, precautions and adverse events sections. A new patient Medication Guide will be available that provides safety information on AVONEX.

The approval was based on a three-year research study called CHAMPS (Controlled High Risk Subjects AVONEX Multiple Sclerosis Prevention Study). Results of the CHAMPS study were published in the New England Journal of Medicine (NEJM) in September 2000 and demonstrated efficacy for this use in early MS. The primary endpoint was time from the first to a second MS attack. AVONEX-treated subjects experienced a 44 percent decrease in the rate of developing a second attack when compared to placebo.

The CHAMPS study was a randomized, double blind, placebo-controlled, Phase III clinical trial involving 383 patients considered at high risk of developing MS because of a recently experienced isolated demyelinating event involving the optic nerve, spinal cord or brainstem/cerebellum, and lesions typical of MS visible on brain MRI. Study participants received either 30 mcg of AVONEX or placebo by IM injection once weekly. AVONEX delayed a second clinical attack and showed a beneficial effect on secondary endpoints including the development of brain abnormalities, or lesions, visible on MRI scans. These findings show that the increase in brain MRI T2 lesion volume at 18 months (which reflects cumulative burden of disease) was 91 percent lower in the group of patients treated with AVONEX compared to the placebo treated group.

The most common side effects associated with AVONEX treatment are flu-like symptoms, 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.

Multiple Sclerosis
Multiple sclerosis (MS) is a chronic disease of the central nervous system that affects approximately 400,000 people in North America and approximately 1 million people worldwide. It is a disease of young adults, mostly women, with onset typically between 20 and 40 years of age. Symptoms of MS may include vision problems, loss of balance, numbness, difficulty walking and paralysis.

AVONEX is the leading treatment for relapsing forms of multiple sclerosis worldwide, with more than 120,000 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 65 countries.

About Biogen
Biogen is the world’s oldest independent biotechnology company and a leader in biologics research, development and manufacturing. A pioneer in leading edge research in immunology, neurobiology and oncology, Biogen brings novel therapies to improve patients’ lives around the world through its global marketing capabilities. For press releases and additional information about the company, please visit http://www.biogen.com.

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