Medivir announces a phase II all-oral study of Simeprevir (TMC435) and VX-135 for the treatment of Hepatitis C to be conducted by Janssen and Vertex

-       Companies to evaluate a two-drug combination of Medivir/Janssen’s
investigational protease inhibitor simeprevir (TMC435) and Vertex’s
investigational nucleotide analogue VX-135
-       Phase II proof-of-concept study to begin in early 2013 to evaluate
safety, tolerability and viral cure rates of 12-week treatment regimen

Stockholm, Sweden—Medivir AB (OMX: MVIR), announced today plans for a phase II
proof-of-concept study of an all-oral regimen for the treatment of hepatitis C
containing of Medivir/Janssen’s protease inhibitor simeprevir and Vertex’s
nucleotide analogue hepatitis C virus (HCV) polymerase inhibitor VX-135. Janssen
will conduct a drug-drug interaction study with simeprevir and VX-135 to support
the planned initiation of a phase II proof-of-concept study in early 2013,
pending discussions with regulatory authorities.

The phase II study is expected to evaluate safety, tolerability and viral cure
rates using a 12-week combination of simeprevir and VX-135, with and without
ribavirin. Janssen and Vertex will jointly fund development costs associated
with the collaboration. There are no up-front or milestone payments associated
with the agreement.

Simeprevir is a potent, once-daily investigational hepatitis C protease
inhibitor, currently in phase III trials, being jointly developed by Medivir AB
and Janssen R&D Ireland. VX-135 is an investigational uridine nucleotide
analogue pro-drug designed to inhibit the replication of the hepatitis C virus
by acting on the NS5B polymerase.

“This study will broaden our understanding of simeprevir, which we believe has
the necessary characteristics to become a key component of future hepatitis C
treatment regimens, including combination with interferon and ribavirin as well
as interferon-free therapies and is in line with Medivir’s and Janssen’s
strategy to evaluate different interferon-free HCV treatment possibilities”
comments Charlotte Edenius, EVP of Research and Development, Medivir AB.

Clinical development plans
Vertex and Janssen expect to initiate a phase II proof-of-concept study of VX
-135 and simeprevir in early 2013, following the completion of a drug-drug
interaction (DDI) study. Costs associated with the studies will be shared
equally between the two companies. The goals of the study will be to evaluate
safety, tolerability and viral cure rates of multiple 12-week combination
regimens (SVR12*) of VX-135 and simeprevir, with and without ribavirin. The
study will include patients who have chronic non-cirrhotic genotype 1 hepatitis
C and have not previously been treated (treatment-naïve). Additional information
on the phase II study will be provided upon initiation of the study.

* SVR12 = undetectable hepatitis C virus 12 weeks after the end of treatment.

For more information please contact:

Medivir                      Direct: +46 8 440 6550
Rein Piir, EVP Corporate     or: Mobile:
Affairs & IR                 +46 708 537 292
M:Communications             medivir@mcomgroup.com
Europe: Mary-Jane Elliott,   +44(0)20 7920 2330
Amber Bielecka, Hollie Vile

About Simeprevir (TMC435)
Simeprevir is a once-daily potent investigational hepatitis C protease inhibitor
in late phase III clinical development being jointly developed by Medivir AB and
Janssen R&D Ireland to treat chronic hepatitis C virus infections. Simeprevir is
being investigated in combination with PegIFN/RBV in phase III trials and is
also being evaluated with Direct-acting Antiviral (DAA) agents in three other
phase II interferon-free combinations both with and without ribavirin (RBV).

Global phase III studies of simeprevir include QUEST-1 and QUEST-2 in treatment
naïve patients, PROMISE in patients who have relapsed after prior IFN-based
treatment and ATTAIN in treatment experienced patients. In parallel to these
trials, phase III studies for simeprevir are ongoing in both treatment naïve and
treatment experienced HIV-HCV co-infected patients, HCV genotype 4 infected
patients and in Japanese HCV genotype 1 patients.

The phase II interferon-free combinations both with and without ribavirin with
simeprevir are:

  · Simeprevir is evaluated in combination with Gilead Science, sofosbuvir
(GS7977) in null responder hepatitis C genotype 1 infected patients.
  · Simeprevir is evaluated in combination wtih BMS, daclatasvir in treatment
-naïve or previous null responder hepatitis C genotype 1 infected patients.
  · Simeprevir is evaluated in combination with TMC647055 (Janssen R&D) and
ritonavir in low doses in treatment-naïve, relapser or null responder hepatitis
C genotype 1 infected patients.

For additional information about simeprevir please see www.clinicaltrials.gov

About VX-135
VX-135 (ALS-2200) is a uridine nucleotide analogue pro-drug that appears to have
a high barrier to drug resistance based on in vitro studies. It is designed to
inhibit the replication of the hepatitis C virus by acting on the NS5B
polymerase. In vitro studies of the compound showed antiviral activity across
all genotypes, or forms, of the hepatitis C virus, including genotypes more
prevalent outside of the United States.

Earlier this year, Vertex announced the first 7-day viral kinetic data for VX
-135. Based on these data, the company plans to initiate multiple all-oral,
phase II proof-of-concept studies, including a study of VX-135 and ribavirin and
a study of VX-135 and telaprevir, the company's approved protease inhibitor
marketed as INCIVEK for people with chronic genotype 1 hepatitis C. Vertex is on
track to initiate the study of VX-135 in combination with ribavirin by the end
of 2012, followed by the study with telaprevir in early 2013. The studies will
evaluate safety, tolerability and viral cure rates of 12-week combination
regimens in people with chronic non-cirrhotic genotype 1 hepatitis C who have
not previously been treated (treatment-naïve).

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 World Health
Organization estimates that nearly 170 million people worldwide, approximately
3% of the world's population, are infected with hepatitis C virus (HCV). The CDC
(Centers for Disease Control and Prevention) has reported that more than three
million people in the United States are chronically infected with HCV.

About Medivir
Medivir is an emerging research-based pharmaceutical company focused on
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 simeprevir
(TMC435), a novel protease inhibitor in phase III clinical development for
hepatitis C that is being developed in collaboration with Janssen R&D Ireland.

In June 2011, Medivir acquired the specialty pharmaceutical company BioPhausia
and today Medivir has a broad product portfolio with prescription
pharmaceuticals in the Nordics.
Medivir’s first product, the unique cold sore product Xerese®/Xerclear®, is
launched in collaboration with GlaxoSmithKline to be sold OTC under the brand
name ZoviDuo in Europe, Japan and Russia.

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

Medivir is a collaborative and agile pharmaceutical company with an R&D focus on
infectious diseases and a leading position in hepatitis C. We are passionate and
uncompromising in our mission to develop and commercialize innovative
pharmaceuticals that improve people’s lives.