Press Release

MONTREAL, June 28, 2017 – Replicor Inc., a privately held biopharmaceutical company targeting a cure for patients with chronic hepatitis B virus (HBV) and chronic HBV and hepatitis delta virus (HDV) co-infection, announced today the publication of its study on the activity of NAPs in recognized in vitro models of HBV infection in the journal PLOS ONE. (

This study assessed the antiviral activity of a variety of NAP compounds, including the clinically active NAPs REP 2055, REP 2139 and REP 2165, in HBV infected HepaRG and primary human hepatocytes in tissue culture. These studies demonstrated that early generation NAPs like REP 2055 had an ability to block viral entry only at high concentrations (5-10μM) while later generation (RNA) NAPs like REP 2139 and REP 2165 had negligible entry effect. Dr. Andrew Vaillant, CSO of Replicor commented, “This study is a classic example of the known challenges of working with this chemical class in tissue culture”, adding “the post-entry effects of NAPs we know to be present could not be observed in these models because the intracellular trafficking of phosphorothioate oligonucleotides (NAPs are in this class) that occurs in patients is absent in tissue culture.”

The study did provide some important advances, demonstrating that the antiviral effects of REP 2139 and REP 2165 in the currently ongoing REP 401 trial are not driven by entry inhibition. Dr. Vaillant went on to state, “This latest study tells us we are focusing our research efforts in the right direction in developing a tissue culture model of HBV infection where the intracellular NAP transit occurring in hepatocytes in patients is restored. The initial results of these efforts were presented at EASL 2017 ( and we will continue to refine our ability to replicate the post-entry effects of NAPs in vitro.”

About Replicor
Replicor is a privately held biopharmaceutical company with the most advanced animal and human clinical data in the development of the cure for HBV and HDV. The company is dedicated to accelerating the development of an effective treatment for patients with HBV and HBV/HDV co-infection. For further information about Replicor please visit our website at

Media Contact:
Natacha Dorget
(514) 733-1998