Medivir Announces Positive 24-week Interim Data of TMC435 From the ASPIRE Study (C206)

Once Daily Novel Therapy in Treatment-Experienced Hepatitis C Patients

HUDDINGE, Sweden, November 18, 2010 - Highlights of the Study

    TMC435 Added to Standard of Care:

    - Increased the response rates and antiviral efficacy, which progressed
      through to week 24

    - Increased the number of patients with undetectable Hepatitis C Virus
    (HCV) levels through week 4, 12 and 24

    - Safe and well tolerated

Medivir AB (OMX: MVIR), the emerging research-based specialty
pharmaceutical company focused on infectious diseases, announces today
positive top-line 24-week interim data from the Phase 2b ASPIRE (C206) study
of TMC435 in treatment-experienced hepatitis C patients. The results
demonstrate the potent and consistent antiviral efficacy of TMC435 in
patients who had failed earlier treatment with peg-IFN and ribavirin
(standard of care), as well as a safety and adverse event profile for TMC435
that is consistent with what Medivir previously reported in the Phase 2b
PILLAR C205 study. TMC435, a hepatitis C protease inhibitor, dosed once daily
(q.d.) is being developed jointly by Tibotec Pharmaceuticals and Medivir.

The ASPIRE study evaluates the effect of TMC435 in combination
with standard of care in 462 patients infected with the difficult to treat
genotype-1 hepatitis C virus who had undergone and failed prior treatment
with standard of care. The study includes patients that have relapsed,
achieved partial response, or achieved no response (null responders) to
treatment with standard of care.

TMC435 was administered once daily at a dose of either 100 mg
or 150mg given for either 12, 24, or 48 weeks in combination with standard of
care. Standard of care treatment was continued until the study completion at
week 48.

Overview of the ASPIRE (C206) Week 24 Interim Study Results

The week 24 interim analysis was performed when all patients
completed 24 weeks of treatment or discontinued earlier. An
Intention-to-Treat (ITT) analysis was performed including all patients who
took at least one dose of TMC435.

In the interim analysis, patients treated with TMC435 and
standard of care demonstrated high response rates and antiviral efficacy in
all patient groups up to and including week 4, 12 and 24. In the relapser
group, 81%, 92% and 94% of patients taking TMC435 and Peg-IFN and ribavirin
achieved undetectable HCV RNA levels at week 4, week 12 and week 24,
respectively. For the partial responder group 62%, 84% and 86% achieved
undetectable HCV RNA levels at week 4, week 12 and week 24, respectively.

The null responder group also demonstrated significant
response rates with 38%, 64% and 78% of patients taking TMC435 and Peg-IFN
and ribavirin achieving undetectable HCV RNA levels at week 4, week 12 and
week 24, respectively. All patients continue on active treatment up until
week 48.

In the table below the TMC435 data pooled and all data are
taken into account at the specific time point.

    An Intention-to-Treat analysis of Virologic Response: HCV
    RNA<25IU/mL undetectable

                                           Partial
         (%)           Relapser*         responder**     Null responder***
                    TMC435   Placebo   TMC435   Placebo   TMC435   Placebo
                    N = 158   N = 27   N = 138   N = 23   N = 100   N = 16
    RVR               81         4       62         0       38         0

    WEEK 4
    cEVR              92        31       84        10       64        21

    WEEK 12
    WEEK 24           94        83       86        19       78        44

*Relapser: undetectable at end of trial (EOT) but detectable within 24
weeks of follow-up

**Partial response: >2 log reduction at Week 12 but not achieving
undetectable at EOT

***Null response: <2 log reduction in HCV RNA at Week 12

Safety and Tolerabillty

An Intention-to-Treat analysis was performed including all
patients who took at least one dose of TMC435. TMC435 was generally safe and
well tolerated and the results were consistent with the previously reported
phase 2b PILLAR C205 study. Significant decreases in transaminases (ALT and
AST) were observed in all TMC435 treatment groups. The two most frequently
reported adverse events (AEs) were fatigue and headache, with comparable
results shown from the placebo group.

                        All TMC435  Placebo
                         N = 396    N = 66
             %
          Fatigue           41        42
         Headache           33        33

Commenting on the results, Ron Long, CEO of Medivir, said: "We
are extremely encouraged and excited by the pronounced efficacy and
advantageous safety of TMC435 in these difficult-to-treat patients that are
in a great need of new and improved treatment options. We are now looking
forward to the next important development milestone for TMC435, the start of
Phase 3 clinical trials in treatment-naive patients in early 2011."

Conference call today

A conference call will take place today at 15:00 (GMT) / 16:00
(CET) / 10:00 (EST) to discuss the Phase 2b TMC435 ASPIRE (C206) data
announced today. Please dial: UK: +44(0)20-7906-8535, Sweden Access Number:
+46(0)85-063-9549 or US Access Number: +1-703-865-2821, no passcode is
required. A seven day replay of the conference call can be accessed via: UK:
+44(0)20-3364-5943, Sweden: +46(0)20-089-6353, US: +1-866-286-6997, please
quote the passcode 281259#.

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. Medivir has a strong R&D portfolio and has
recently launched its first product Xerese(TM)/Xerclear(TM). Medivir's key
pipeline asset, TMC435, a protease inhibitor, is in phase 2b clinical
development for Hepatitis C and is partnered with Tibotec Pharmaceuticals.

Xerese(TM)/Xerclear(TM) is an innovative treatment for cold
sores, which has been approved in both the US and Europe. It is partnered
with GSK to be sold OTC in Europe and Russia and with Meda in North America.
Medivir has retained the Rx rights for Xerclear(TM) in Sweden and Finland.

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

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 CDC
has reported that almost three million people in the United States are
chronically infected with HCV.

About TMC435 clinical trial programs

TMC435 is a once daily protease inhibitor jointly developed by
Medivir and Tibotec Pharmaceuticals to treat hepatitis C virus infections.
TMC435 is currently being studied 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. TMC435 is planned to enter
phase 3 studies early 2011.

PILLAR Study (TMC435-C205)

TMC435-C205 is an ongoing randomized double-blind global phase
2b study in 386 genotype-1 treatment-naive patients. It evaluates once daily
treatment of TMC435 with different doses and durations given in addition to
standard of care treatment, consisting of ribavirin and pegIFNalpha-2A. Week
24 interim results were presented as a late-breaker oral presentation at
AASLD 61st Annual Meeting of the American Association for the Study of Liver
Diseases (AASLD) in Boston, MA., USA.

ASPIRE Study (TMC435-C206)

TMC435-C206 is an ongoing randomized double-blind global phase
2b study in 462 genotype-1 treatment-experienced patients. It evaluates once
daily treatment of TMC435 in with different doses of given in addition to
standard of care treatment, consisting of ribavirin and pegIFNalpha-2A.

DRAGON Study (TMC435-C215)

TMC435-C215 is an ongoing Japanese phase 2b study in 92
genotype-1 treatment-naive patients. It evaluates once daily treatment of
TMC435 with different doses and durations given in addition to standard of
care treatment, consisting of ribavirin and pegIFNalpha-2A.

Opera-2 (TMC435-C202)

TMC435-C202 is a completed phase 2a study in treatment-naive
genotype 2 to 6 HCV patients. It is a once daily treatment of TMC435 during
seven days, at 200 mg. Subsequently, patients could continue with SoC
treatment consisting of pegylated interferon and ribavirin upon agreement
with the study doctor.

    For more information about Medivir, please contact:

    Medivir (www.medivir.se)

    Rein Piir, CFO & VP Investor Relations,  Mobile: +46-708-537-292

    M:Communications Medivir@mcomgroup.com

    Europe: Mary-Jane Elliott / Amber Bielecka, +44(0)20-7920-2330
    USA: Jason Marshall,  +1-212-897-5497

For more information about Medivir, please contact: Medivir (www.medivir.se), Rein Piir, CFO & VP Investor Relations, Mobile: +46-708-537-292, M:Communications: Medivir at mcomgroup.com, Europe: Mary-Jane Elliott / Amber Bielecka, +44(0)20-7920-2330; USA: Jason Marshall, +1-212-897-5497