Biogen Idec Submits Application to FDA for First Long-Lasting Factor VIII Therapy for Hemophilia A

  Biogen Idec Submits Application to FDA for First Long-Lasting Factor VIII
  Therapy for Hemophilia A

  Half-life of rFVIIIFc may enable prophylactic dosing once to twice weekly

Business Wire

WESTON, Mass. -- March 12, 2013

Biogen Idec (NASDAQ: BIIB) announced today that the company has submitted a
Biologics License Application (BLA) to the U.S. Food and Drug Administration
(FDA) for the marketing approval of recombinant factor VIII Fc fusion protein
(rFVIIIFc) for the treatment of hemophilia A. Recombinant FVIIIFc is the first
hemophilia A product candidate in a new class of long-lasting clotting factor
therapies being developed with the goal of reducing the burden of treatment
for this condition. If approved, rFVIIIFc will be the first major advance in
hemophilia A treatment in more than two decades. The regulatory submission was
based on results from A-LONG, the largest registrational phase 3 clinical
study in hemophilia A to date.

“This regulatory submission marks another significant step toward our goal of
transforming thecare of hemophilia for patients, families and caregivers,”
said Glenn Pierce, M.D., Ph.D., senior vice president of Global Medical
Affairs and chief medical officer of Biogen Idec’s hemophilia therapeutic
area. “In our phase 3 study, patients treated with rFVIIIFc were able to
inject rFVIIIFc once-weekly to twice-weekly, which creates the potential for
those currently on prophylactic treatment to reduce injections by 50 to 100
per year. Moreover, patients currently treating bleeding episodescould
potentially dose prophylactically once per week andmaintain significant
protection from bleeding with about the same totalnumber ofinjections each
year they use to treat bleeding episodes today.”

Typically, prophylaxis in hemophilia A requires injections three times per
week or every other day to maintain a sufficient circulating level of clotting
factor to provide protection from bleeding. Without prophylactic treatment,
people with hemophilia A remain at risk of bleeding episodes that can cause
irreversible joint damage and life threatening hemorrhages.

On March 4, 2013 Biogen Idec announced the FDA accepted for review the
company’s BLA for its factor IX candidate, rFIXFc, for use in patients with
hemophilia B.

About the Fc Fusion Technology Platform

Recombinant FVIIIFc is a clotting factor developed using Biogen Idec’s novel
and proprietary monomeric Fc fusion technology, which makes use of a naturally
occurring pathway that delays the destruction of factor and cycles it back
into the bloodstream, resulting in a longer circulating half-life.

With this technology, rFVIIIFc is designed to provide long-lasting protection
from bleeding and reduce the treatment burden associated with hemophilia A,
which currently can require approximately 150 to 180 injections annually for
prophylaxis with commercially available factor VIII products. Fc fusion
technology is used in seven FDA-approved products for the long-term treatment
of chronic diseases including rheumatoid arthritis, psoriasis and platelet
disorders.

About Hemophilia A

Hemophilia A is a rare, inherited disorder in which the ability of a person’s
blood to clot is impaired. Hemophilia A occurs in about one in 5,000 male
births annually and is caused by having substantially reduced or no factor
VIII activity, which is needed for normal blood clotting. People with
hemophilia A therefore need injections of factor VIII to restore the
coagulation process and prevent frequent bleeds that could otherwise lead to
pain, irreversible joint damage and life-threatening hemorrhages. The Medical
and Scientific Advisory Council of the National Hemophilia Foundation
recommends prophylaxis as the optimal therapy for people with severe
hemophilia A.

About the Biogen Idec and Sobi Collaboration

Biogen Idec and Swedish Orphan Biovitrum (Sobi) are partners in the
development and commercialization of rFIXFc in hemophilia B and rFVIIIFc in
hemophilia A. Biogen Idec leads development, has manufacturing rights, and has
commercialization rights in North America and all other regions excluding the
Sobi territory. Sobi has the right to opt in to assume final development and
commercialization in Europe including Russia, the Middle East and Northern
Africa.

AboutBiogen Idec

Through cutting-edge science and medicine,Biogen Idecdiscovers, develops and
delivers to patients worldwide innovative therapies for the treatment of
neurodegenerative diseases, hemophilia and autoimmune disorders. Founded in
1978,Biogen Idecis the world’s oldest independent biotechnology company.
Patients worldwide benefit from its leading multiple sclerosis therapies, and
the company generates more than$5 billionin annual revenues. For product
labeling, press releases and additional information about the company, please
visit www.biogenidec.com.

Safe Harbor

This press release contains forward-looking statements, including statements
about the dosage, commercialization and impact of long-lasting hemophilia
therapies and regulatory filings. These statements may be identified by words
such as "believe," "expect," "may," "plan," "potential," "will" and similar
expressions, and are based on our current beliefs and expectations. Drug
development and commercialization involve a high degree of risk. Factors which
could cause actual results to differ materially from our current expectations
include the risk that unexpected concerns may arise from additional data or
analysis, regulatory authorities may require additional information or further
studies, or may fail to approve or may delay approval of our drug candidates,
or we may encounter other unexpected hurdles. For more detailed information on
the risks and uncertainties associated with our drug development and
commercialization activities, please review the Risk Factors section of our
most recent annual or quarterly report filed with the Securities and Exchange
Commission. Any forward-looking statements speak only as of the date of this
press release and we assume no obligation to update any forward-looking
statements, whether as a result of new information, future events or
otherwise.

Contact:

Biogen Idec Media Contact:
Amanda Galgay, +1-781-464-3260
Public Affairs
or
Biogen Idec Investor Relations Contact:
Kia Khaleghpour, +1-781-464-2442
Director, Investor Relations