Biogen Idec and Sobi Present New Data from the Phase 3 Study of Their Long-Lasting Hemophilia Factor Candidate ALPROLIX™

  Biogen Idec and Sobi Present New Data from the Phase 3 Study of Their
  Long-Lasting Hemophilia Factor Candidate ALPROLIX™

Additional B-LONG Study Results Support Positive Clinical Profile of ALPROLIX
                               for Hemophilia B

Business Wire

WESTON, Mass. and STOCKHOLM -- July 2, 2013

Biogen Idec (NASDAQ: BIIB) and Swedish Orphan Biovitrum AB (publ) (Sobi) (STO:
SOBI) today presented new findings for their long-lasting recombinant factor
IX candidate ALPROLIX^* for hemophilia B at the XXIV International Society on
Thrombosis and Haemostasis (ISTH) Congress in Amsterdam, The Netherlands.
Three oral presentations showcase new data that reinforce the potential
safety, efficacy and pharmacokinetic profile of ALPROLIX. The data highlight
the consistency of results with ALPROLIX across patient types and favorable
physician ratings of its efficacy in treating acute bleeding episodes and
controlling bleeding during and after major surgery.

“ALPROLIX is the first product candidate in a new class of long-lasting
clotting factor therapies, and the data presented today support the potential
of the therapy to reduce the frequency of prophylactic infusions for patients
with hemophilia B,” 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. “These new data help to build the clinical profile of
ALPROLIX by increasing our understanding of its efficacy.”

Treatment of Bleeding

An evaluation of the treatment of acute bleeding episodes across the
prophylaxis and episodic (on-demand) treatment arms of the phase 3 B-LONG
study showed that more than 90% of bleeds were controlled with a single
injection of ALPROLIX and more than 97% were controlled with two or fewer
injections. These data were showcased in the e-poster presentation:

  *Treatment of Bleeding Episodes in Subjects with Haemophilia B with the
    Long-Lasting Recombinant Factor IX Fc Fusion Protein (rFIXFc) in the Phase
    3 B-LONG Study

Surgery Analysis

Results from an analysis of the phase 3 B-LONG study showed that ALPROLIX
consistently controlled bleeding during and after 14 major surgeries in 12
patients with hemophilia B. Physicians reported high efficacy levels of
ALPROLIX during surgery, with hemostasis (the stoppage of bleeding) rated as
“excellent” for 13/14 surgeries and “good” for 1/14 surgeries. According to
investigator analyses, the results were comparable to that for similar
surgeries in people without hemophilia. These data were showcased in the
e-poster presentation:

  *Long-Lasting Recombinant Factor IX Fc Fusion (rFIXFc) for Perioperative
    Management of Subjects with Haemophilia B in the Phase 3 B-LONG Study

Population Pharmacokinetics (PK) Analysis

Analysis of a population pharmacokinetics (popPK) model developed for ALPROLIX
demonstrated that the model accurately predicts peak and trough factor IX
activity levels achieved in the B-LONG clinical study at a variety of ALPROLIX
doses. These data were showcased in the e-poster presentation:

  *Clinical Implications of Population Pharmacokinetics of rFIXFc in Routine
    Prophylaxis, Control of Bleeding and Perioperative Management for
    Haemophilia B Patients

“These new data from the B-LONG study support the potential application of Fc
fusion technology in hemophilia,” said Birgitte Volck, M.D., Ph.D., senior
vice president development and chief medical officer of Sobi. “The results add
to the growing body of evidence supporting the potential efficacy and safety
of this long-lasting clotting factor candidate for the treatment of hemophilia
B.”

ALPROLIX Global Regulatory Status

A Biologics License Application (BLA) for Biogen Idec’s long-lasting
hemophilia product candidate ALPROLIX is currently under review with the U.S.
Food and Drug Administration (FDA) for the treatment of hemophilia B.

Marketing Applications for ALPROLIX have been submitted in Canada and
Australia for the treatment of hemophilia B. Additional regulatory filings are
planned.

About the Fc Fusion Technology Platform

ALPROLIX is a clotting factor under development using Biogen Idec’s novel and
proprietary monomeric Fc fusion technology, which makes use of a naturally
occurring pathway that delays the breakdown of factor in the body and cycles
it back into the bloodstream, resulting in a longer circulating half-life. Fc
fusion technology is used in seven FDA-approved products for the treatment of
chronic diseases including rheumatoid arthritis, psoriasis and platelet
disorders. Biogen Idec is the first and only to apply this proprietary
technology to hemophilia.

About Hemophilia B

Hemophilia B is a rare, inherited disorder in which the ability of a person's
blood to clot is impaired. Hemophilia B occurs in about one in 25,000 male
births annually and is caused by having substantially reduced or no factor IX
activity, which is needed for normal blood clotting. People with hemophilia B
experience bleeding episodes that can cause pain, irreversible joint damage
and life-threatening hemorrhage. Injections of factor IX can restore the
coagulation process, control bleeding, and prevent new bleeding episodes. The
Medical and Scientific Advisory Council of the National Hemophilia Foundation
recommends prophylaxis as the optimal therapy for people with severe
hemophilia B. According to the World Federation of Hemophilia, prophylaxis in
hemophilia B typically requires injections up to three times per week to
maintain a sufficient circulating level of clotting factor.

About the Biogen Idec and Sobi Collaboration

Biogen Idec and Swedish Orphan Biovitrum (Sobi) are partners in the
development and commercialization of ELOCTATE in hemophilia A and ALPROLIX in
hemophilia B. 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.

About Sobi

Sobi is an international specialty healthcare company dedicated to rare
diseases. Our mission is to develop and deliver innovative therapies and
services to improve the lives of patients. The product portfolio is primarily
focused on inflammation and genetic diseases, with three late stage biological
development projects within hemophilia and neonatology. We also market a
portfolio of specialty and rare disease products for partner companies. Sobi
is a pioneer in biotechnology with world-class capabilities in protein
biochemistry and biologics manufacturing. In 2012, Sobi had total revenues of
SEK 1.9 billion (€ 215 M) and about 500 employees. The share (STO: SOBI) is
listed on NASDAQ OMX Stockholm. More information is available at www.sobi.com.

Biogen Idec Safe Harbor

This press release contains forward-looking statements, including statements
about the potential impact and therapeutic effect of our long-lasting
hemophilia product candidates 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.

*ALPROLIX^TM Coagulation Factor IX (Recombinant Fc Fusion Protein)

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Contact:

BIOGEN IDEC CONTACT:
Media Contact:
Todd Cooper, +1-781-464-3260
Senior Director, Public Affairs
or
Investor Relations Contact:
Ben Strain, +1-781-464-2442
Senior Manager, Investor Relations
or
SWEDISH ORPHAN BIOVITRUM CONTACT:
Media Contact:
Oskar Bosson, +46 70410 71 80
Head of Communications
or
Analyst/Investor Contact:
Jörgen Winroth, +46 8 697 20 00
Vice President, Head of Investor Relations