Two phase III trials evaluating once-daily Simeprevir and Sofosbuvir in hepatitis C infected patients have been initiated

Stockholm, Sweden — Medivir AB (OMX: MVIR) today announces that two phase III
trials are recruiting patients to examine the efficacy and safety of the NS3/4A
protease inhibitor simeprevir in combination with the nucleotide inhibitor
sofosbuvir for the treatment of chronic genotype 1 hepatitis C virus (HCV)
infection in treatment-naïve and treatment-experienced patients with and without
cirrhosis.

“Positive safety and efficacy results have previously been demonstrated in
genotype 1 HCV infected patients with the interferon- and ribavirin free
combination of simeprevir and sofosbuvir in the phase II COSMOS study. The
OPTIMIST trials aim to further consolidate these data and to explore a shorter
treatment duration of eight weeks to potentially further simplify this promising
treatment option,” says Charlotte Edenius, EVP Development, Medivir AB

Study design
OPTIMIST-1
The first trial, called OPTIMIST-1 or TMC435HPC3017, is a phase III, open-label,
randomized study investigating the efficacy and safety of simeprevir 150 mg in
combination with sofosbuvir 400 mg.
The combination will be administered once daily for 8 or 12 weeks in chronic HCV
genotype 1 infected patients without cirrhosis who are HCV treatment naïve or
treatment experienced. This study will enroll approximately 300 patients in the
U.S. and Canada.

OPTIMIST-2
The second trial, called OPTIMIST-2 or TMC435HPC3018, is a phase III, open
-label, single-arm study investigating the efficacy and safety of simeprevir 150
mg in combination with sofosbuvir 400 mg.
The combination will be administered once daily for 12 weeks in HCV genotype 1
infected patients with cirrhosis who are HCV treatment naïve or treatment
experienced. This study will enroll approximately 100 patients in the U.S. and
Canada.

Ribavirin will not be administered in the OPTIMIST trials. The primary efficacy
endpoint in each study is the proportion of patients achieving sustained
virologic response 12 weeks after the end of treatment (SVR12).

For additional information, including inclusion and exclusion criteria for these
trials, please visit www.clinicaltrials.gov

COSMOS study
The combination of simeprevir and sofosbuvir was previously evaluated in the
phase II COSMOS trial.
The final cohort 1 study results (SVR12) in patients without fibrosis or
cirrhosis (METAVIR score of F0-2) and the interim cohort 2 study results (SVR4)
in patients with fibrosis or cirrhosis (METAVIR score of F3-4) from the COSMOS
study were presented at the American Association for the Study of Liver Diseases
(AASLD) Annual Meeting 2013 in Washington, D.C.

Final cohort 2 results (SVR12) have been accepted for presentation at the
European Association for the Study of the Liver (EASL) International Liver
Congress 2014 on April 12.

For more information please contact:
Rein Piir, EVP Corporate Affairs & IR, mobile: +46 708 537 292

Medivir is required under the Securities Markets Act to make the information in
this press release public. The information was submitted for publication at
13.00 CET on 2 April 2014.

About Simeprevir
Simeprevir is an NS3/4A protease inhibitor jointly developed by Janssen R&D
Ireland and Medivir AB and indicated for the treatment chronic hepatitis C
infection in combination with pegylated interferon and ribavirin in HCV genotype
1 and 4 infected patients with compensated liver disease, including cirrhosis.

Janssen is responsible for the global clinical development of simeprevir and has
exclusive, worldwide marketing rights, except in the Nordic countries. Medivir
AB will retain marketing rights for simeprevir in these countries under the
marketing authorization held by Janssen-Cilag International NV. The treatment
was approved for the treatment of genotype 1 hepatitis C in September 2013 in
Japan and in November 2013 in Canada and the U.S. and in March 2014 in Russia.
The Committee for Medicinal Products for Human Use (CHMP) recently recommended
Marketing Authorisation in the European Union for the use of Simeprevir in
combination with other medicinal products for the treatment of chronic hepatitis
C (CHC) in adult patients. An approval is expected during Q2-2014.

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, a novel protease inhibitor for the treatment of hepatitis C that is
being developed in collaboration with Janssen R&D Ireland. The company is also
working with research and development in other areas, such as bone disorders and
neuropathic pain. Medivir has also a broad product portfolio with prescription
pharmaceuticals in the Nordics.