Initiation of a phase IIa clinical trial with

Initiation of a phase IIa clinical trial with investigational  hepatitis C
protease inhibitor TMC435350

Medivir (OME: MVIRB SS) announced today that, following the successful
completion of a phase I study in both healthy volunteers and patients
chronically infected with hepatitis C virus (HCV), the phase IIa study,
TMC435350-C201, of the investigational hepatitis C (HCV) protease inhibitor
TMC435350. The study will start shortly in Europe by Tibotec Pharmaceuticals
Ltd., who are collaborating with Medivir on the development of TMC435350.

TMC435350-C201 is a phase IIa proof-of-concept, blinded, randomized,
placebo-controlled trial to assess the effectiveness, safety, tolerability, and
pharmacokinetics of four different dose regimens of TMC435350 (25 mg daily, 75mg
daily, 200mg daily, 400mg daily).  96 treatment-naïve and 24
treatment-experienced patients with chronic genotype-1 HCV infection will be
enrolled in the trial which will be conducted at more than 20 sites in Europe.
Patients will receive either TMC435350 or placebo once daily (qd) for 28-days. 
Standard of Care (SoC) treatment, peginterferon alpha-2a (Pegasys®) and
ribavirin (Copegus®), will be provided for 48 weeks or, optionally, for 24 weeks
for those patients with an undetectable HCV viral load at Week 4 and who remain
undetectable at Week 20. Patients will be followed-up for 24 weeks after the end
of SoC to allow evaluation of sustained virologic response (SVR).

In the phase I study TMC435350 was administrated at 200 mg qd for five days to
patients chronically infected with genotype-1 hepatitis C virus (HCV). The viral
load reductions met the target set for the trial. These results will be
submitted for presentation at the Annual Meeting of the European Association for
the Study of the Liver in Milan in April 2008

The earlier phase I study results were reported at the AASLD Liver Meeting in
Boston, November 2-6 2007. They showed that in this study TMC435350 was
generally well-tolerated when given to HCV-negative healthy volunteers at single
oral doses up to 600 mg, and at 5 days of oral doses up to 400 mg. The plasma
levels of TMC435350 24 hours after day 5 dosing at 200 mg qd were more than
250-fold in excess of the HCV replicon EC50 value. 


For more information about the phase IIa study, visit www.clinicaltrials.gov

For additional information, please contact
Rein Piir, CFO & Vice President, Investor Relations, Medivir AB, +46 8 5468 3123
or +46 708 53 72 92

For further information on Medivir, please see our website: www.medivir.se
Initiation of a phase IIa clinical trial with investigational hepatitis C protease inhibitor TMC435350

Attachments
