Medivir — M&A Activity 2011

May 23, 2011

NOT FOR RELEASE, DISTRIBUTION OR PUBLICATION INTO OR IN THE UNITED STATES, AUSTRALIA, CANADA, JAPAN OR THE REPUBLIC OF SOUTH AFRICA.

Press Release 23 May 2011

Addendum to offer document made public regarding Medivir's offer for BioPhausia and extension of the acceptance period

Medivir AB (publ) ("Medivir"), the emerging research-based specialty pharmaceutical company focused on infectious diseases, today made public an addendum to the offer document regarding Medivir's offer for BioPhausia AB (publ) (the "Offer"). The addendum is made public due to Medivir's press release on 20 May 2011 regarding positive 48-week interim data from TMC435 hepatitis C phase 2b ASPIRE study in treatment-experienced genotype-1 patients.

In light hereof, Medivir has resolved to extend the acceptance period of the Offer to 15:00 p.m. on 30 May 2011. Accordingly, acceptances of the Offer must be made no later than at such point in time in accordance with the instructions set out in the offer document. Subject to the Offer being declared unconditional no later than on or around 7 June 2011, settlement is expected to commence on or around 15 June 2011.

The Swedish language addendum is available on www.medivir.com and www.avanza.se. The addendum can be ordered free of charge from Avanza, telephone number +46 (0)8 562 251 22.

For further information, please contact:

Medivir (www.medivir.com)

Rein Piir, CFO & VP Investor Relations +46 (0)708 537 292

Medivir is required under the Securities Markets Act to make the information in this press release public. The information was submitted for publication at 14.00 p.m. CET on 23 May 2011.

Medivir in Brief

Medivir is an emerging research-based specialty pharmaceutical company focused on the development of high-value treatments for infectious diseases. Medivir has world class expertise in polymerase and protease drug targets and drug development which has resulted in a strong infectious disease R&D portfolio. The company's key pipeline asset is TMC435, a protease inhibitor which has recently entered phase 3 clinical development for hepatitis C and is partnered with Tibotec Pharmaceuticals. Medivir is headquartered in Huddinge, Sweden. Medivir's class B shares are admitted to trading on NASDAQ OMX Stockholm, Mid Cap.

BioPhausia in Brief

BioPhausia is a Swedish specialty pharma company. The business is divided into three main segments: Own products, Licensed products and Parallel-imported products. The portfolio of pharmaceuticals includes disease areas such as gastrointestinal, CNS (central nervous system) and emergency medicine, and includes, inter alia, products such as Mollipect and Citodon. Operations are carried out in the Nordic countries with a unit for repackaging in Poland. BioPhausia is headquartered in Stockholm, Sweden. The BioPhausia shares are admitted to trading on NASDAQ OMX Stockholm, Small Cap. BioPhausia's Listed Warrants are also listed on NASDAQ OMX Stockholm.

NOT FOR RELEASE, DISTRIBUTION OR PUBLICATION INTO OR IN THE UNITED STATES, AUSTRALIA, CANADA, JAPAN OR THE REPUBLIC OF SOUTH AFRICA.

Important Information

This announcement is not for distribution or transmission, directly or indirectly, in or into the United States, Canada, Australia, Japan or the Republic of South Africa and does not constitute, or form part of, an offer to purchase, subscribe for, sell or exchange or the solicitation of an offer to purchase, subscribe for, sell or exchange any securities to any person in the United States, Canada, Australia, Japan or the Republic of South Africa, nor the solicitation of any vote or approval in any such jurisdiction, nor shall there be any sale, issue or transfer of the securities referred to in this announcement in any jurisdiction in contravention of applicable law (the "Restricted Jurisdictions"). The Offer is not being made, directly or indirectly, in or into the United States or any other Restricted Jurisdiction, or by use of the mails, or by any means or instrumentality (including, without limitation, facsimile transmission, telephone and the internet) of interstate or foreign commerce, or of any facility of a national securities exchange, of the United States or any other Restricted Jurisdiction and the Offer cannot be accepted by any such use, means, instrumentality or facility or from within the United States or any other Restricted Jurisdiction. The Medivir shares have not been and will not be registered under the US Securities Act of 1933, as amended (the "Securities Act") and may not be offered or sold in the United States unless registered under the Securities Act or an exemption from such registration is available. No offering of Medivir shares is being made in the United States.