First interim results from a phase IIa study evaluating an all-oral regimen of Simeprevir and Sofosbuvir in prior null responder Hepatitis C patients

Stockholm, Sweden — Medivir AB (OMX: MVIR) today announced first interim results
from the cohort 1 of a Phase IIa study of the investigational protease inhibitor
simeprevir (TMC435) administered once daily with Gilead’s investigational
nucleotide inhibitor sofosbuvir (GS-7977) with and without ribavirin for 12 and
24 weeks in genotype 1 prior null-responder hepatitis C patients with mild to
moderate fibrosis (METAVIR F0-2). Simeprevir is jointly developed by Medivir AB
and Janssen R&D Ireland, an affiliate of the Janssen Pharmaceutical Companies.

Further data will be presented this week at the 20th Conference on Retroviruses
and Opportunistic Infections (CROI) on March 6 in Atlanta, Georgia, USA.

Cohort 1 of the phase IIa open-label COSMOS study randomized 80 genotype 1
patients into one of four arms including 150 mg of once-daily simeprevir plus
400 mg of sofosbuvir for 24 weeks with or without ribavirin or for 12 weeks with
or without ribavirin.

Summary of data available at the time of the interim analysis when submitted to
CROI:

Virologic response rates with 150 mg simeprevir (SMV) and 400 mg sofosbuvir
(SOF) q.d. with or without ribavirin (RBV).

+------------+--------------+---------+--------------+---------+
|Patients n/N|SMV + SOF +RBV|SMV + SOF|SMV + SOF +RBV|SMV + SOF|
|            |   24 weeks   |24 weeks |   12 weeks   |12 weeks |
|            |    (n=24)    | (n=15)  |    (n=27)    | (n=14)  |
+------------+--------------+---------+--------------+---------+
|    EoT     |     4/4      |   5/5   |     7/7      |   3/3   |
|    SVR4    |     3/3      |   3/3   |     5/5      |   3/3   |
|   SVR12    |     2/2      |   1/1   |     5/5      |   2/2   |
+------------+--------------+---------+--------------+---------+

q.d.: en gång om dagen; EoT: behandlingsslut; SVR4 och SVR12: patienter med
odetekterbara nivåer HCV RNA ( HCV RNA (

The regimen of once-daily simeprevir and sofosbuvir with or without ribavirin
was generally well tolerated and no serious adverse events occurred during the
treatment period for the patients involved in the study.

The COSMOS (Combination Of SiMeprevir and sOfosbuvir in HCV genotype 1 infected
patientS) study will also include a second cohort that will investigate similar
treatment regimens and durations in HCV genotype 1 prior null-responder and
treatment-naïve patients with METAVIR scores of F3-F4.

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

About the COSMOS Trial
COSMOS is a randomized, open-label study investigating the efficacy and safety
of 12 or 24 weeks of simeprevir and sofosbuvir with or without ribavirin in HCV
genotype 1 patients who are treatment naïve or have prior null response to
pegylated interferon and ribavirin therapy.

Cohort 1 of the COSMOS study enrolled 80 genotype 1 prior null-responder HCV
patients with METAVIR scores of F0-F2, who were stratified by IL28B status and
genotype 1 subtype, into one of four arms including once-daily simeprevir (150
mg) plus sofosbuvir (400 mg) for 24 weeks with or without ribavirin, or once
-daily simeprevir (150 mg) plus sofosbuvir (400 mg) for 12 weeks with or without
ribavirin.

Cohort 2 of the study will investigate similar treatment regimens and durations
in genotype 1 prior null-responder and treatment-naïve patients with METAVIR
scores of F3-F4. The Metavir score is used to quantify the degree of
inflammation and fibrosis of the liver. Liver fibrosis is scored on a four-point
scale.

About Simeprevir
Simeprevir, an investigational NS3/4A protease inhibitor jointly developed by
Janssen R&D Ireland and Medivir AB, is currently in late phase III studies as a
once-daily capsule (150 mg) taken in combination with pegylated interferon and
ribavirin for the treatment of genotypes 1 and 4 HCV.

Global phase III studies of simeprevir include QUEST-1 and QUEST-2 in treatment
-naïve patients, PROMISE in patients who have relapsed after prior interferon
-based treatment and ATTAIN in null-responder patients. In parallel to these
trials, phase III studies for simeprevir are ongoing in treatment-naïve and
treatment-experienced HIV-HCV co-infected patients, HCV genotype 4 patients and
Japanese HCV genotype 1 patients. Janssen Pharmaceutical K.K. recently announced
the submission of a new drug application for simeprevir in Japan for the
treatment of genotype 1 hepatitis C.

Simeprevir is being studied in phase II interferon-free trials with and without
ribavirin in combination with:

  · Janssen’s non-nucleoside inhibitor TMC647055 and ritonavir in treatment
-naïve genotype 1a and 1b HCV patients;
  · Gilead Sciences, Inc.’s nucleotide inhibitor sofosbuvir (GS-7977) in
treatment-naïve and previous null-responder genotype 1 HCV patients; and
  · Bristol-Myers Squibb's NS5A replication complex inhibitor daclatasvir (BMS
-790052) in treatment-naive and previous null-responder genotype 1 HCV patients.

In addition, Janssen Pharmaceutical Inc. recently announced that it has entered
into a non-exclusive collaboration with Vertex Pharmaceuticals to evaluate in a
phase II study the safety and efficacy of an all-oral regimen of simeprevir and
Vertex’s investigational nucleotide analogue polymerase inhibitor VX-135 for the
treatment of HCV. As a first step, Janssen Pharmaceutical Inc. will conduct a
drug-drug interaction (DDI) study with simeprevir and VX-135.

Janssen Pharmaceutical Inc. also recently announced plans to initiate a phase
IIa trial of an investigational interferon-free regimen with simeprevir,
TMC647055 and Idenix’s IDX719, a once-daily NS5A inhibitor, with and without
ribavirin.

For additional information about simeprevir clinical trials, please visit
www.clinicaltrials.gov.

About Sofosbuvir
Sofosbuvir (formerly referred to as GS-7977) is a once-daily nucleotide analog
polymerase inhibitor for the treatment of HCV infection being developed by
Gilead Sciences. Sofosbuvir is being evaluated as part of multiple therapeutic
regimens, including programs with RBV alone and in combination with peg-IFN and
RBV.

About Hepatitis C
Hepatitis C, a blood-borne infectious disease of the liver and a leading cause
of chronic liver disease and liver transplants, is a rapidly evolving treatment
area with a clear need for innovative treatments. Approximately 150 million
people are infected with hepatitis C worldwide, and 350,000 people per year die
from the disease.

About Medivir AB
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 in late phase III clinical development for hepatitis C that is being
developed in collaboration with Janssen R&D Ireland. Medivir has also a broad
product portfolio with prescription pharmaceuticals in the Nordics.

For more information about Medivir AB, 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.