New Phase III Data from Once-Daily Simeprevir Presented at the Conference of the Asian Pacific Association for the Study of the Liver (APASL)

Stockholm, Sweden — Medivir AB (OMX: MVIR) today announced that new phase III
data for the once-daily protease inhibitor simeprevir have been presented at the
Conference of the Asian Pacific Association for the Study of the Liver (APASL)
in Brisbane, Australia.

  · The phase III ATTAIN study in treatment-experienced adult patients with
chronic hepatitis C virus (HCV) and compensated liver disease achieved its
primary efficacy endpoint by demonstrating non-inferiority of simeprevir
compared to telaprevir when both are given in combination with PegIFN/RBV.
Simeprevir demonstrated superior safety profile including fewer adverse events
(AEs), fewer serious adverse events (SAEs) and less anemia versus telaprevir.

  · Pooled analysis of data from the phase III QUEST-1 and QUEST-2 studies
confirmed efficacy in treatment-naïve genotype 1b HCV patients, with 85 percent
(ITT analysis) of treatment-naïve patients achieving SVR12 when treated with
simeprevir in combination with PegIFN/RBV, compared to 53 percent when treated
with placebo in combination with PegIFN/RBV.

  · In the PROMISE phase III trial of prior relapse patients, a subgroup
analysis of genotype 1b patients demonstrated that 86 percent (ITT analysis) of
these patients achieved SVR12 when treated with simeprevir in combination with
PegIFN/RBV, compared to 43 percent when treated with placebo in combination with
PegIFN/RBV.

“We are very pleased to report on the successfully completed phase III ATTAIN
study demonstrating non-inferiority of simeprevir compared with telaprevir, and
a superior safety profile in this difficult to treat patient group. Moreover,
the further analysis of the genotype 1b HCV patients of the phase III studies
QUEST-1, QUEST-2 and PROMISE demonstrated very high SVR12 rates supporting the
strength of simeprevir as a treatment option for this large patient population”
says Charlotte Edenius, EVP Development, Medivir AB.

ATTAIN
About the ATTAIN study
The multicenter phase III clinical study of treatment-experienced genotype 1 HCV
patients partial- and null-responder patients to at least one previous course of
PegIFN/RBV therapy called the ATTAIN study is a randomized, double-blind, two
-arm study. In the trial, 771 patients were randomized (1:1) to treatment with
either 150 mg of simeprevir once daily plus PegIFN/RBV or 750 mg of telaprevir
three times per day plus PegIFN/RBV for 12 weeks, followed by 36 weeks of
PegIFN/RBV alone.

Results from the ATTAIN study
Results from ATTAIN show that simeprevir achieved its primary endpoint of non
-inferiority to telaprevir in treatment-experienced HCV patients and
demonstrated a superior safety profile. In the study, 54 percent of chronic HCV
genotype 1 prior partial- and null-responder patients treated with simeprevir
administered once daily in combination with pegylated interferon and ribavirin
achieved the primary endpoint of sustained virologic response 12 weeks after end
of treatment (SVR12) compared to 55 percent of patients treated with telaprevir
administered three-times daily plus pegylated interferon and ribavirin.

Among prior null-responder patients, 44 percent of patients in the simeprevir
arm achieved SVR12 versus 46 percent of patients in the telaprevir arm. Among
prior partial-responder patients, 70 percent of patients in the simeprevir arm
achieved SVR12 versus 69 percent of patients in the telaprevir arm.

SVR12 rates across patient subgroups were generally similar between the
simeprevir and telaprevir arms, including among patients with the HCV genotype
1a Q80K mutation. Twenty-seven percent of patients with the HCV Q80K mutation
achieved SVR12 in the simeprevir arm versus 26 percent in the telaprevir arm.
The study also found that 60 percent of patients with the IL28B CC genotype, 55
percent of CT patients and 48 percent of TT patients in the simeprevir arm
achieved SVR12, versus 67, 57 and 50 percent of patients in the telaprevir arm,
respectively.

The most common adverse events during the first 12 weeks of treatment occurred
at a consistently lower frequency in the simeprevir treatment arm compared to
the telaprevir treatment arm, including pruritus (31 percent versus 43 percent),
fatigue (32 percent versus 38 percent), headache (25 percent versus 29 percent),
anemia (13 percent versus 37 percent), and nausea (17 percent versus 28
percent). Thirty-four percent and 18 percent of simeprevir-treated patients
experienced on-treatment failure and relapse, respectively, compared to 32
percent and 17 percent of telaprevir-treated patients, respectively. Two percent
of patients in the simeprevir arm and eight percent of patients in the
telaprevir arm discontinued treatment early due to an adverse event. Serious
adverse events were reported in two percent of patients in the simeprevir arm
and nine percent of patients in the telaprevir arm.

QUEST-1, QUEST-2 and PROMISE
Pooled analyses of the QUEST-1, QUEST-2 and PROMISE studies of simeprevir
combination therapy in genotype 1b HCV patients
In a pooled analysis of the QUEST-1 and QUEST-2 studies, 89 percent of treatment
-naïve genotype 1b HCV patients treated with simeprevir in combination with
pegylated interferon and ribavirin and met the criteria for response guided
therapy (94 percent) achieved SVR12 compared to 53 percent of patients treated
with placebo in combination with pegylated interferon and ribavirin (ITT
-analysis 85 and 53 percent, respectively). In patients typically considered
difficult to treat, 71 percent of patients with the IL28B TT genotype and 78
percent with METAVIR F3-F4 scores achieved SVR12 in the simeprevir arm. Two
percent of patients in each treatment arm discontinued treatment with simeprevir
or placebo early due to an adverse event.

An analysis of the PROMISE study found that 89 percent of prior-relapser
genotype 1b HCV patients treated with simeprevir in combination with pegylated
interferon and ribavirin and met the criteria for response guided therapy (95
percent) achieved SVR12 compared to 43 percent of patients treated with placebo
in combination with pegylated interferon and ribavirin (ITT-analysis 86 and 43
percent, respectively). In patients typically considered difficult to treat, 68
percent of patients with the IL28B TT genotype and 84 percent with METAVIR F3-F4
scores achieved SVR12 in the simeprevir arm. No patients discontinued treatment
with either simeprevir or placebo due to adverse events during the entire
treatment phase in this analysis of PROMISE.

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
08.30 CET on 17 March 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 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 USA. A Marketing Authorisation
Application was submitted to the European Medicines Agency (EMA) in April 2013
by Janssen-Cilag International NV seeking approval of simeprevir for the
treatment of genotype 1 or genotype 4 chronic hepatitis C. This application is
under review by the EMA.

Simeprevir is also being studied in several interferon-free regimens using
selected combinations of direct-acting antiviral agents with different
mechanisms of action. To date, more than 3,700 patients have been treated with
simeprevir in clinical trials.

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.

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