Press Release

Replicor to disclose new mechanism of action data and interim REP 2055 and REP 2139 clinical efficacy data in patients with chronic hepatitis B at the 2011 HEPDART meeting.

December 4-8, 2011, Grand Hyatt Kauai, Koloa, Hawaii

November 25, 2011 – Replicor will disclose new mechanism of action data and updated interim results from its two proof of concept clinical trials with REP 2055 and REP 2139 at the 2011 HEPDART meeting to be held from December 4th-8th, 2011. This exclusive meeting is only held every two years and convenes the top experts, opinion leaders and industry analysts. This meeting focuses on advancements in the development of drugs for the treatment of Hepatitis B and Hepatitis C.

REP 2055 and REP 2139 represent a new class of antiviral agent (nucleic acid polymers or NAPs) that block the release of hepatitis B surface antigen (HBsAg) which has been associated with HBV-specific immune defects contributes to the long term persistence of HBV infection in the liver. REP 2055 and REP 2139 rapidly clear HBsAg in the serum of patients infected with HBV and appears to allow these patients to regain effective immunological control over their infection, resulting in sustained virologic responses after only 5-6 months of treatment. Replicor will present updated clinical efficacy results in a poster presentation running from December 5th-8th.

The 2011 HEPDART meeting.