Press Release

25 September 2012, Oxford, England.

September 25, 2012 – Replicor is currently undertaking a proof of concept trial in patients with chronic hepatitis B (HBV) undergoing treatment with its nucleic acid polymer (NAP) REP 2139 in combination with Zadaxin™ or Pegasys™. The hepatitis B surface antigen protein (HBsAg) is produced in large excess by the HBV infection as subviral particles (SVPs) which act to block the immune response to HBV infection. NAPs act to block the release of SVPs from infected hepatocytes, providing an effective method for clearing HBsAg from the blood. The elimination of HBsAg in the blood of HBV-infected patients is well known to be the best indicator of a curative response to treatment.

Interim results from Replicor’s proof of concept trial were disclosed today at the 2012 held at the University of Oxford Christ Church and Examination Schools, Oxford, England. Patients who had cleared HBsAg from their blood with REP 2139 monotherapy were subjected to combination treatment with REP 2139 and either Pegasys™ or Zadaxin™. Profound increases in anti-HBV antibodies or immune function were observed in all patients with as few as 6-10 weeks of combination treatment. Many patients have achieved HBV antibody levels seen in healthy patients after vaccination with a total of 12 weeks of combination treatment. All patients who have achieved this therapeutic vaccine-like response have been removed from treatment and continue to control their viral infections off treatment. The remainder of patients are expected to achieve full immunological control of their infection in the coming weeks. Replicor expects that the profound reactivation of a therapeutically effective immune response with short term Zadaxin™ or Pegasys™ treatment given in combination with its HBsAg release inhibitor REP 2139 can achieve durable immunological in most patients, regardless of viral genotype or state of their HBV infection.

2012 International Meeting of Molecular Biology of Hepatitis B Viruses.