HUDDINGE, Sweden, July 6, 2011 /PRNewswire/ --

Medivir AB (OMX: MVIR), is an emerging research-based specialty pharmaceutical company focused on infectious diseases.

Medivir today announced that its investigational protease inhibitor TMC435 has received "Fast Track" designation by the U.S. Food and Drug Administration ("FDA") for the treatment of chronic hepatitis C (CHC) genotype-1 infection. This is based on TMC435's potential to address unmet medical needs in the treatment of CHC infection compared to currently approved therapies.

TMC435 may offer:

- High sustained virological response (SVR) rates in genotype-1 HCV-infected patients, including hard-to-treat subgroups - Short treatment duration - Favourable overall safety and tolerability profile - A convenient once-daily (q.d.) dosing regimen

Furthermore, Medivir also confirms the intention to start a proof-of-concept oral, interferon-free phase 2 trial, investigating the combination of TMC435, a once daily NS3/4A protease inhibitor (PI) for the treatment of genotype-1 chronic hepatitis C virus (HCV) infection and Pharmasset's PSI-7977, a once daily nucleotide NS5B polymerase inhibitor. The phase 2 study, which is being managed by Tibotec Pharmaceuticals, will investigate the efficacy and safety of 12 weeks or 24 weeks of TMC435 150 mg q.d. in combination with PSI-7977 400 mg q.d. with or without ribavirin in prior null responders to peginterferon/ribavirin therapy. The primary endpoint of the trial will be sustained virological response at 12 weeks (SVR12).

Bertil Samuelsson, CSO, of Medivir commented, "We are delighted to have received the Fast Track designation for TMC435 from the FDA. This shows that TMC435, with its high safety profile, efficacy, short treatment duration and convenience of once daily dosing, is believed to have the potential to provide benefit over current treatments. We believe TMC435 has the potential to become a cornerstone of future direct-acting antiviral combinations for HCV therapy. We are thus very pleased over the clinical collaboration agreement Pharmasset announced today with Tibotec, and the coming start-up of a TMC435 combination trial with Pharmasset's once daily NS5B nucleotide inhibitor PSI-7977. This is one of several ongoing TMC435 combination trials and we expect the momentum to continue with regards to the development of TMC435."