REP 2139-Mg and REP 2165-Mg Combination Therapy in Chronic Hepatitis B Infection

Chronic Hepatitis B Clinical Trial

Official title: An Open-label, Randomized, Active Controlled, Parallel Comparison Study of the Safety and Efficacy of REP 2139-Mg in Combination With Pegasys® and Viread® and REP 2165-Mg in Combination With Pegasys® and Viread® in Patients With HBeAg Negative Chronic Hepatitis B

Status Completed

Clinical Trial Summary

NAPs have been previously shown to clear serum hepatitis B virus surface antigen (HBsAg) both preclinically (in duck HBV infected ducks) and in human patients. REP 2139-Ca mediated HBsAg clearance acts synergistically with immunotherapeutic agent pegylated interferon-alpha 2a to restore host immunological control of HBV infection. REP 2165 is a version of REP 2139 which has been shown preclinically to retain antiviral activity with lower accumulation in the liver.

Both REP 2139 and REP 2165 used in this protocol are formulated as magnesium chelate complexes, which improve their administration tolerability. This open label, randomized and controlled study will examine the safety and efficacy of REP 2139-Mg and REP 2165-Mg therapy in patients with HBeAg negative chronic hepatitis B when used in combination with tenofovir disoproxil fumarate and pegylated interferon alpha-2a.

Clinical Trial Description

Nucleic acid polymers (NAPs) utilize the sequence independent properties of phosphorothioated oligonucleotides to target apolipoprotein interactions involved in the formation of HBV subviral particles (SVPs) which are comprised mainly of the hepatitis B surface antigen protein (HBsAg). The effect of NAPs is to block the formation of SVPs inside infected hepatocytes which prevents their secretion. As SVPs account for > 99.99% of HBsAg in the blood, NAPs are an effective approach for clearing HBsAg from the serum of HBV infected patient.

Previous clinical trials have demonstrated that treatment with the NAP REP 2139 (REP 2139-Ca) results in the rapid and effective clearance ofHBsAg from the blood. This HBsAg removal has the immediate effect of unmasking the underlying, pre-existing anti-HBsAg (anti-HBs) response, allowing clearance of HBV virus from the blood.

Although REP 2139-Ca has been shown to be safe in human patients, it shares the same class effect as other phosphorothioate oligonucleotides in that it accumulates in the liver with repeated dosing. REP 2165 is a version of REP 2139 which is designed to have an increased rate of degradation to slow down liver accumulation while keeping its antiviral activity intact. The antiviral efficacy of REP 2165 has been shown to be comparable to REP 2139 in a pre-clinical model of HBV infection with significantly less accumulation in the liver. As such, REP 2165 is expected to have comparable antiviral efficacy in human patients with reduced liver accumulation during treatment.

HBsAg has important immunosuppressive effects in HBV infection which have been shown to block both adaptive and innate immune processes. Removal of HBsAg from the blood of patients removes this immunosuppressive effect.

Thus, an important additional effect of removal of HBsAg from the blood is to greatly enhance the effect of pegylated interferon alpha 2a. It is expected that elimination of serum HBsAg with REP 2139-Mg or REP 2165-Mg will lead to creation of a favourable immunological activation in the absence of HBsAg, appearance of free anti-HBs, clearance of HBV virions in the blood and synergistic immunostimulation with conventional dosing of pegylated interferon alpha-2a and improved control of HBV infection in the presence of tenofovir disoproxil fumarate (TDF). All patients will receive 24 weeks of monotherapy with TDF prior to entry into experimental or active comparator arms. ;

Related Conditions & MeSH terms

• Chronic Hepatitis B
• Hepatitis
• Hepatitis A
• Hepatitis B
• Hepatitis B, Chronic
• Hepatitis, Chronic

• NCT number: NCT02565719
• Study type: Interventional
• Source: Replicor Inc.
• Status: Completed
• Phase: Phase 2
• Start date: March 2016
• Completion date: May 2019