Oral Compound BG-12 Achieves Primary Endpoint in Phase II Study of Relapsing-Remitting Multiple Sclerosis; Treatment with BG-12 Led to Statistically Significant Reductions in MRI measures

Biogen Idec (NASDAQ: BIIB) and Fumapharm AG announced
positive results from a Phase II study designed to evaluate the
efficacy and safety of BG-12, an oral fumarate, in patients with
relapsing-remitting multiple sclerosis (MS). The study achieved its
primary endpoint, demonstrating that treatment with BG-12 led to a
statistically significant reduction in the total number of
gadolinium-enhancing brain lesions as measured by MRI with six months
of treatment versus placebo. These data were presented today at the
annual meeting of the European Neurological Society in Lausanne,
Switzerland.
"We are encouraged that these Phase II data demonstrate that BG-12
may be a promising oral therapy to treat MS. As part of our ongoing
commitment to MS patients, we are working with regulatory authorities
to determine the next steps in the development of this program," said
Burt Adelman, MD, executive vice president, Development, Biogen Idec.
This Phase II multi-center, double-blind, placebo-controlled,
dose-ranging study enrolled 257 patients at sites in 10 countries in
Europe. Patients were randomized to receive placebo or BG-12 at 120
mg, 360 mg, or 720 mg per day for six months. The patient group
treated with 720 mg of BG-12 per day had a 69% reduction in the mean
number of gadolinium-enhancing lesions versus placebo as measured
monthly from weeks 12 to 24 of the study. The 720 mg dose group also
had a 48% reduction in newly enlarging T2-hyperintense lesions. BG-12
therapy was also associated with a trend towards reduction in relapse
rate. The patient group treated with 720 mg of BG-12 per day had a 32%
reduction in relapse rate compared to placebo, however, the study was
not designed to achieve statistical significance for this endpoint.
The results of the 120 mg and 360 mg BG-12-treated groups were not
statistically significant versus placebo. Patients were followed for
an additional six months as part of a dose-blinded safety extension
study.
The most common adverse events were flushing, gastrointestinal
disorders, headache, and nasopharyngitis. The incidence of liver
enzyme elevation greater than or equal to three times the upper limit
of normal at any time during the placebo controlled phase of the study
was between 2% and 8% in the three active treatment groups, compared
with 5% in the placebo group. Improvement in liver enzyme levels was
seen after discontinuation of BG-12. Infection rates were found to be
balanced between the BG-12-and placebo-treated groups and no
opportunistic infections occurred.

About Biogen Idec

Biogen Idec creates new standards of care in oncology, neurology
and immunology. As a global leader in the development, manufacturing,
and commercialization of novel therapies, Biogen Idec transforms
scientific discoveries into advances in human healthcare. For press
releases and additional information about the company, please visit
http://www.biogenidec.com.

About Fumapharm AG

Fumapharm has licensed exclusive worldwide rights to develop and
market BG-12 to Biogen Idec. Fumapharm is a privately held
pharmaceutical company headquartered in Lucerne, Switzerland. For more
information, please visit http://www.fumapharm.ch.

Safe Harbor/Forward-Looking Statements

This press release contains forward-looking statements regarding
the development of BG-12 for multiple sclerosis. These statements are
based on our current beliefs and expectations. They are subject to the
risks inherent in drug development, including the risks that the
effects of the product in larger clinical trials may not be as
expected or that there may be safety issues or other problems or
delays that arise during clinical trials, unexpected technical or
manufacturing hurdles, or intellectual property disputes. There is no
certainty that the risk/benefit profile of the product will be
acceptable to the Company or to regulatory authorities for a
particular indication. Drug development involves a high degree of
risk. Only a small number of research and development programs result
in the commercialization of a product.
Success in early stage clinical trials does not ensure that later
stage or larger scale clinical trials will be successful. For more
detailed information on the risks and uncertainties associated with
these forward looking statements and Biogen Idec's other activities
see the periodic and other reports that Biogen Idec has filed with the
SEC. Biogen Idec does not undertake any obligation to publicly update
any forward-looking statements.