First data on TMC435350 in patients with hepatitis C who have failed previous
treatment shows antiviral activity 

The data from a small explorative study will be presented tomorrow at the 43rd
Annual Meeting of the European Association for the Study of the Liver (EASL) in
Milan, Italy. These are the first data to be presented on the use of TMC435350
in Hepatitis C patients. There will also be a poster presentation under the
title; “Once-daily regimens of the HCV NS3/4A-protease inhibitor TMC435350 are
predicted to provide therapeutic exposure in plasma and liver”.     

Medivir and Tibotec Pharmaceuticals Ltd discovered TMC435350 through a research
collaboration. TMC435350 is a potent inhibitor of the hepatitis C virus (HCV)
NS3/4A serine protease and is presently in a phase IIa proof-of-concept trial
(OPERA- 1) in Europe.

Data about the study
The objective of the phase Ia study was to evaluate, pharmacokinetics and safety
of TMC435350 in healthy volunteers and pharmacokinetics, safety and antiviral
activity in HCV infected patients in the following 1b study. The study included
52 healthy volunteers and 6 patients with HCV infection who were given
TMC435350. 

Results from the phase Ib study
Five days dosing with 200 mg TMC435350 dosed once-daily resulted in a median
reduction of viral load of 3.9 log10 units/mL on day 6. Rapid decline in HCV
viral load was observed in all patients, both genotype 1a and 1b. There was no
viral breakthrough observed during dosing or in the following three days. At a
four week follow-up, plasma levels of HCV-RNA had returned to baseline in all
patients. Observed adverse events in patients and healthy volunteers were all
assessed as being mild and no serious adverse events were observed. There were
no study-medication related discontinuations. 

Conclusion
TMC435350 was well tolerated during five days of dosing and exhibited strong and
rapid antiviral activity in HCV genotype 1 infected patients. The results of
this phase I trial in both healthy volunteers and patients with HCV infection
formed the basis for the ongoing phase IIa trial throughout Europe.   

The poster to be presented at EASL could be found at www.medivir.com 
/Investor & Media/Latest events 

For additional information, please contact
Rein Piir, CFO & VP Investor Relations, Medivir +46 8 5468 3123 or +46 708 537
292.