Medivir Announces Start of Phase 1a Trial of the Hepatitis C Polymerase Inhibitor TMC649128

HUDDINGE, Sweden, February 10, 2011 - Medivir AB (OMX: MVIR), the emerging research-based specialty
pharmaceutical company focused on infectious diseases, today announces the
start of a phase 1a clinical trial with TMC649128 intended for the treatment
of chronic hepatitis C virus infection.

TMC649128 is a nucleoside NS5B polymerase inhibitor that has already
demonstrated an attractive pre-clinical profile. It is anticipated that this
profile would see TMC649128 be used in combination with HCV directly acting
antiviral agents, given their high genetic barrier to resistance and
antiviral activity across multiple HCV genotypes.

In pre-clinical studies, TMC649128 displayed in vitro activity across
multiple HCV genotypes and a high genetic barrier to resistance.

The phase 1a trial is a double-blind, randomized, placebo-controlled
single-ascending dose trial to assess the safety, tolerability and
pharmacokinetics in healthy volunteers and will be conducted in Belgium.
TMC649128 is being developed in collaboration with Tibotec Pharmaceuticals.

Milestone payment

Medivir entered a Research and Development agreement in the field of
hepatitis C virus polymerase with Ortho Biotech Products LP, an affiliate of
Tibotec in May 2008. The development of TMC649128 falls under this agreement
and by entering clinical development, a milestone payment of Euro 7 million
has been triggered for payment to Medivir.

"We are extremely excited to see TMC649128, our first HCV nucleoside
inhibitor, move into clinical development", stated Bertil Samuelsson, CSO of
Medivir. "The start of this phase 1a trial underlines Medivir's commitment to
the development of novel and innovative hepatitis C treatments. We view
nucleoside inhibitors as cornerstone components of future HCV treatment
paradigms in combination with directly acting antiviral agents and a
TMC649128 component could set them apart from other HCV drug classes."

About Hepatitis C

Hepatitis C is a blood-borne infectious disease of the liver and is a
leading cause of chronic liver disease and liver transplants. The WHO
estimates that nearly 180 million people worldwide, or approximately 3% of
the world's population, are infected with hepatitis C virus (HCV). The CDC
has reported that almost three million people in the United States are
chronically infected with HCV.

About Medivir's Commitment of the HCV Area

Medivir and Tibotec are also jointly developing the once daily protease
inhibitor TMC435 for treatment of hepatitis C virus infections (HCV).

About Medivir

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. Medivir has a strong R&D portfolio and has recently
launched its first product Xerese(TM)/Xerclear(R). Medivir's key pipeline
asset, TMC435, a protease inhibitor, is in phase 2b clinical development for
Hepatitis C and is partnered with Tibotec Pharmaceuticals.

Xerese(TM)/Xerclear(R) is an innovative treatment for cold sores, which
has been approved in both the US and Europe. It is partnered with
GlaxoSmithKline to be sold OTC in Europe and Russia and with Meda AB in North
America. Medivir has retained the Rx rights for Xerclear(R) in Sweden and
Finland.

For more information about Medivir, please visit the Company's website:
www.medivir.se

For more information about Medivir, please contact;

    Medivir (www.medivir.se)

    Rein Piir, CFO & VP Investor Relations
    Mobile: +46-708-537-292
    M:Communications

    Europe: Mary-Jane Elliott / Amber Bielecka /
    Nick Francis
    Medivir@mcomgroup.com
    +44(0)20-7920-2330

    USA: Jason Marshall
    +1-212-897-5497

Rein Piir, CFO & VP Investor Relations, Mobile: +46-708-537-292, M:Communications; Europe: Mary-Jane Elliott / Amber Bielecka / Nick Francis, Medivir at mcomgroup.com , +44(0)20-7920-2330; USA: Jason Marshall, +1-212-897-5497