Sobi publishes prospectus supplement regarding the rights issue

NOT FOR DISTRIBUTION, DIRECTLY OR INDIRECTLY, IN OR INTO AUSTRALIA, CANADA,
JAPAN, HONG KONG, SINGAPORE, SOUTH AFRICA, SWITZERLAND OR THE UNITED STATES OR
IN ANY JURISDICTION IN WHICH THE DISTRIBUTION OR RELEASE WOULD BE UNLAWFUL.

Swedish Orphan Biovitrum AB (publ) ("Sobi") today publishes a supplement to the
prospectus made public on 5 May 2011 in respect of the invitation to subscribe
for shares in Sobi. The prospectus supplement includes Sobi's and Biogen Idec's
announcement dated 9 May 2011 that the European Medicines Agency (EMA) has
adopted an opinion agreeing to the pediatric investigational plan for the
companies' long-lasting, fully-recombinant Factor IX Fc fusion protein (rFIXFc).

The prospectus supplement has been approved by and registered at the Swedish
Financial Supervisory Authority (the SFSA) and is available on the website of
the SFSA www.fi.se, on Sobi's website www.sobi.com, on Carnegie's website
www.carnegie.se and on Handelsbanken's website
www.handelsbanken.se/investmentoffer.

Those investors who have applied for or in any other manner consented to the
purchase or subscription of securities covered by the rights issue, before the
publication of the prospectus supplement, are entitled to withdraw their
application or consent up to and including 18 May 2011 (i.e. within five working
days from the publication of the prospectus supplement). Such withdrawal must be
submitted in writing to Carnegie Investment Bank AB, Transaction Support, SE-
103 38 Stockholm, Sweden. If the subscription application was submitted through
a trustee, the investor shall contact its trustee regarding any withdrawal.
Subscriptions that are not withdrawn will remain binding and those subscribers
who wish to remain as subscribers do not need to take any further action.

For additional information, please contact
Åsa Stenqvist, VP Communications and Investor Relations
Telephone: +46 8-697 20 00

About Swedish Orphan Biovitrum (Sobi)
Sobi is a leading European specialty pharmaceutical company. The company is
focused on providing and developing specialty pharmaceuticals for patients with
rare diseases and significant medical needs. The portfolio comprises about 60
marketed products, as well as projects in late clinical phase. Key therapeutic
areas are hematological diseases, autoimmune diseases, hereditary metabolic
disorders and therapeutic oncology. In 2010 Sobi had revenues of SEK 1.9 B and
approximately 500 employees. The share (STO: SOBI) is listed on NASDAQ OMX
Stockholm. For more information please visitwww.sobi.com.

The above information has been made public in accordance with the Swedish
Securities Market Act and/or the Financial Instruments Trading Act. The
information was released for public distribution on
11 May 2011 at 12.15 p.m. CET.

IMPORTANT INFORMATION

The information in this press release is not intended for distribution,
publication or public release, directly or indirectly, in or into Australia,
Canada, Hong Kong, Japan, Singapore, South Africa, Switzerland, the United
States or any other jurisdiction where the distribution of this press release
may be unlawful. The distribution of this announcement may be restricted by law
in certain jurisdictions and persons into whose possession any document or other
information referred to herein comes should inform themselves about and observe
any such restriction.

The information in this press release is not an offer to sell or a solicitation
to buy shares. This press release is not a prospectus under the Prospectus
Directive 2003/71/EC. A prospectus will be prepared and published in accordance
with the Prospectus Directive and will thereafter be made available by the
Company. Investors shall not subscribe for securities referred to in this press
release other than on the basis of the information which will be included in
such prospectus.

The information in this press release does not constitute or form a part of any
offer or solicitation to purchase or subscribe for securities in the United
States. The securities mentioned herein have not been, and will not be,
registered under the United States Securities Act of 1933 (the "Securities Act")
or under the securities laws of any state or other jurisdiction in the United
States, and may not be offered or sold in the United States, except pursuant to
an exemption from, or in a transaction not subject to, the registration
requirements of the Securities Act. There will be no public offer of securities
in the United States.

The information in this press release may not be forwarded or distributed to any
other person and may not be reproduced in any manner whatsoever. Any forwarding,
distribution, reproduction, or disclosure of this information in whole or in
part may be prohibited. Failure to comply with these instructions may result in
a violation of the Securities Act or the applicable laws of other jurisdictions.

This press release may contain forward-looking statements. Words such as
"expect", "believe", "estimate", "plan" and "forecast" in this press release are
intended to indicate forward-looking statements. These forward looking
statements reflect the current expectations on future events of the management
at the time such statements are made, but are made subject to risks and
uncertainties. All these forward-looking statements are based on the
expectations and assumptions of the management and are deemed reasonable but
uncertain and difficult to predict. Actual outcomes and results may differ
significantly from the forward looking statements. The Company does not intend,
nor undertakes, to update any such forward looking statements.