Press Release

Replicor presents clinical efficacy and toxicology results in patients with chronic hepatitis B with short term exposure to immunotherapy after REP 2139-ca induced clearance of serum HBsAg.

14 May 2013, Boston, U.S.A.

May 14th, 2013 – Replicor has previously undertaken a proof of concept trial to examine the efficacy of REP 2055 monotherapy in patients with chronic HBV infection. A second proof of concept trial is currently underway in patients with chronic hepatitis B (HBV) undergoing treatment with REP 2139-ca in combination with Zadaxin™ or Pegasys™.

Efficacy and toxicology results in Replicor’s proof of concept trials from monotherapy exposure to REP 2055 or REP 2139-ca were disclosed on Tuesday May 14th, 2013 at the 15th annual TIDES meeting held in Boston, U.S.A.

Both REP 2055 and REP 2139-ca were shown to rapidly and effectively remove HBsAg from the blood of patients with HBV infection. While REP 2055 monotherapy led to the establishment of control of infection off treatment in 2/7 patients, the addition of immunotherapy (either Pegasys™ or Zadaxin™) after REP 2139-ca mediated HBsAg clearance led to profound increases in immune function in all patients and in 8 out of 9 patients, control their viral infection has been maintained for 12 – 24 weeks after all treatment is stopped.

Toxicology results from weekly monotherapy exposure to REP 2055 or REP 2139-ca in many cases > 1 year resulted in no observable drug related effects on liver and kidney function or in lipid or hematological function. Major reported symptoms were shown to be related to the development of mineral deficiency likely due to the mineral chelation properties of these compounds and were controlled or prevented with proper mineral supplementation during treatment.

These results show the well tolerated nature of long term treatment with the nucleic acid polymer compounds REP 2055 and REP 2139-ca and further show the promise of achieving well tolerated control of HBV infection with combination treatments using these agents.

The 15th annual TIDES meeting.