July 6, 2011

TMC435 has Received Fast Track Designation From the FDAandTMC435 Will be Studied in Combination WithPharmasset’s PSI-7977 for HCV genotype-1

HUDDINGE, Sweden, July 6, 2011 /PRNewswire/ --

Medivir AB (OMX: MVIR), is an emerging research-based specialty
pharmaceutical company focused on infectious diseases.

Medivir today announced that its investigational protease inhibitor
TMC435 has received "Fast Track" designation by the U.S. Food and Drug
Administration ("FDA") for the treatment of chronic hepatitis C (CHC)
genotype-1 infection. This is based on TMC435's potential to address unmet
medical needs in the treatment of CHC infection compared to currently
approved therapies.

TMC435 may offer:

        - High sustained virological response (SVR) rates in
          genotype-1 HCV-infected patients, including hard-to-treat subgroups
        - Short treatment duration
        - Favourable overall safety and tolerability profile
        - A convenient once-daily (q.d.) dosing regimen

Furthermore, Medivir also confirms the intention to start a
proof-of-concept oral, interferon-free phase 2 trial, investigating the
combination of TMC435, a once daily NS3/4A protease inhibitor (PI) for the
treatment of genotype-1 chronic hepatitis C virus (HCV) infection and
Pharmasset's PSI-7977, a once daily nucleotide NS5B polymerase inhibitor.
The phase 2 study, which is being managed by Tibotec Pharmaceuticals, will
investigate the efficacy and safety of 12 weeks or 24 weeks of TMC435 150 mg
q.d. in combination with PSI-7977 400 mg q.d. with or without ribavirin in
prior null responders to peginterferon/ribavirin therapy. The primary
endpoint of the trial will be sustained virological response at 12 weeks

Bertil Samuelsson, CSO, of Medivir commented, "We are delighted to have
received the Fast Track designation for TMC435 from the FDA. This shows that
TMC435, with its high safety profile, efficacy, short treatment duration and
convenience of once daily dosing, is believed to have the potential to
provide benefit over current treatments. We believe TMC435 has the potential
to become a cornerstone of future direct-acting antiviral combinations for
HCV therapy. We are thus very pleased over the clinical collaboration
agreement Pharmasset announced today with Tibotec, and the coming start-up
of a TMC435 combination trial with Pharmasset's once daily NS5B nucleotide
inhibitor PSI-7977. This is one of several ongoing TMC435 combination trials
and we expect the momentum to continue with regards to the development of

About Fast Track

Fast Track is a process designed to facilitate the development, and
expedite the review of drugs to treat serious diseases and to fill an unmet
medical need. The purpose is to get important new drugs to the patient
earlier. Fast Track addresses a broad range of serious diseases. "Filling an
unmet medical need" is defined as providing a therapy where none exists or
providing a therapy that may potentially be superior to existing therapy. If
there are existing therapies, a fast track drug must show some advantage
over available treatment, such as:

        - Showing superior effectiveness
        - Avoiding serious side effects of an available treatment
        - Improving the diagnosis of a serious disease where early
          diagnosis results in an improved outcome
        - Decreasing a clinically significant toxicity of an accepted

A drug that receives Fast Track designation is eligible for some or all
of the following:

        - More frequent meetings with the FDA to discuss the drug's
          development plan and ensure collection of appropriate data needed to
          support drug approval
        - More frequent written correspondence from the FDA about such
          things as the design of the proposed clinical trials
        - Eligibility for Accelerated Approval, i.e., approval on an
          effect on a surrogate or substitute endpoint reasonably likely to
          predict clinical benefit
        - Rolling Review, which means that a drug company can submit
          completed sections of its New Drug Application (NDA) for review by FDA,
          rather than waiting until every section of the application is completed
          before the entire application can be reviewed. NDA review usually does
          not begin until the drug company has submitted the entire application to
          the FDA
        - Dispute resolution if the drug company is not satisfied with an
          FDA decision not to grant Fast Track status.

In addition, most drugs that are eligible for Fast Track designation are
likely to be considered appropriate to receive a Priority Review.

Once a drug receives Fast Track designation, early and frequent
communication between the FDA and a drug company is encouraged throughout
the entire drug development and review process. The frequency of
communication assures that questions and issues are resolved quickly, often
leading to earlier drug approval and access by patients.

About TMC435

TMC435, an investigational CHC protease inhibitor currently in phase 3
clinical development, is a highly potent, selective and safe once-daily
(q.d.) drug jointly developed by Tibotec Pharmaceuticals to treat chronic
hepatitis C virus infections.

TMC435 is being developed in combination with PegIFN/RBV and in
combination with Direct-acting Antiviral (DAA) agents without peginterferon
and with or without ribavirin (RBV). In June 2011 the combination study of
TMC435 with TMC647055, a non-nucleoside NS5B polymerase inhibitor being
developed by Tibotec Pharmaceuticals, was initiated.

Three global clinical phase 3 response guided studies were initiated in
early 2011 by Tibotec:

        - TMC435-C208 or QUEST-1 includes approximately 375
          treatment-naive patients
        - TMC435-C216 or QUEST-2 includes approximately 375
          treatment-naive patients
        - TMC435-C3007 or PROMISE includes approximately 375 who have
          relapsed after prior interferon-based treatment

Phase 3 programs for TMC435 are also ongoing in Japan.

In parallel with the recent start of the global phase 3-studies, TMC435
is currently in a follow up phase in three phase 2b clinical trials
(TMC435-C205, TMC435-C206 and TMC435-C215) in G1 treatment-naive and in G1
patients that failed previous IFN-based treatment. More safety and efficacy
data from the phase 2b trials will be presented at scientific meetings later
in 2011.

For additional information from these studies, please see
http://www.medivir.com and http://www.clinicaltrials.gov

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 US
Centers for Disease Control ("CDC") has reported that almost three million
people in the United States are chronically infected with 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 which has resulted in a strong infectious disease R&D
portfolio. The Company's key pipeline asset is TMC435, a novel protease
inhibitor is in phase 3 clinical development for hepatitis C and is
partnered with Tibotec Pharmaceuticals. In June 2011, Medivir acquired the
specialty pharmaceutical company BioPhausia to ensure timely
commercialization of TMC435 in the Nordic markets, once approved.

Medivir's first product, the unique cold sore product Xerese(TM)/Xerclear(
R) was launched on the US market in February 2011. Xerese(TM)/Xerclear(R),
which has been approved in both the US and Europe is partnered with
GlaxoSmithKline to be sold OTC in Europe, Japan and Russia. Rights in North
America, Canada and Mexico have recently been sold to Meda AB. Medivir has
retained the Rx rights for Xerclear(R) in Sweden and Finland.

For more information about Medivir, please visit the Company's website:

        For more information about Medivir, please contact:

        Medivir (http://www.medivir.com):
        Rein Piir, CFO & VP Investor Relations
        Mobile: +46-708-537-292

        Peter Laing / Amber Bielecka / Katja Toon
        [email protected]

        USA: Roland Tomforde

SOURCE Medivir