Medivir AB has announced plans for a phase II proof-of-concept study of an all-oral regimen for the treatment of hepatitis C containing of Medivir/Janssen's protease inhibitor simeprevir and Vertex's nucleotide analogue hepatitis C virus (HCV) polymerase inhibitor VX-135. Janssen will conduct a drug-drug interaction study with simeprevir and VX-135 to support the planned initiation of a phase II proof-of-concept study in early 2013, pending discussions with regulatory authorities. 

The phase II study is expected to evaluate safety, tolerability and viral cure rates using a 12-week combination of simeprevir and VX-135, with and without ribavirin. Janssen and Vertex will jointly fund development costs associated with the collaboration. There are no up-front or milestone payments associated with the agreement.

 Simeprevir is a once-daily investigational hepatitis C protease inhibitor, currently in phase III trials, being jointly developed by Medivir AB and Janssen R&D Ireland. VX-135 is an investigational uridine nucleotide analogue pro-drug designed to inhibit the replication of the hepatitis C virus by acting on the NS5B polymerase. 

 "This study will broaden our understanding of simeprevir, which we believe has the necessary characteristics to become a key component of future hepatitis C treatment regimens, including combination with interferon and ribavirin as well as interferon-free therapies and is in line with Medivir's and Janssen's strategy to evaluate different interferon-free HCV treatment possibilities" comments Charlotte Edenius, EVP of Research and Development, Medivir AB. 

 Vertex and Janssen expect to initiate a phase II proof-of-concept study of VX-135 and simeprevir in early 2013, following the completion of a drug-drug interaction (DDI) study. Costs associated with the studies will be shared equally between the two companies. The goals of the study will be to evaluate safety, tolerability and viral cure rates of multiple 12-week combination regimens (SVR12 - undetectable hepatitis C virus 12 weeks after the end of treatment) of VX-135 and simeprevir, with and without ribavirin. The study will include patients who have chronic non-cirrhotic genotype 1 hepatitis C and have not previously been treated (treatment-naive).

Additional information on the phase II study will be provided upon initiation of the study.