CChronic HBV and HCV infections represent significant public health issues globally. HBV infection affecting over 250 million people in Asia and the Western Pacific. On the other hand, about 170 million people are infected with HCV. HBV and HCV share common modes of transmission and as a result, combined HBV and HCV infection is frequent. The prevalence of HBV/HCV co-infection in US was 1.4% according to a large multicenter study. However, another prospective study reported the prevalence of HBV/HCV co-infection was 5.8%. High prevalence (>10%) of the HBV co-infection was be observed in Taiwan. The clinical features and chronicity rates were comparable to patients with acute HBV or HCV infection. However, patients with HCV superinfection had higher cumulative rates of liver cirrhosis and hepatocellular carcinoma (HCC) than acute HBV superinfection.
Compared to HBV or HCV single infection, HBV/HCV co-infection may have a more profound impact on the immunological response. Recently, treatment of Chronic HCV is advancing quickly with the approval of oral direct acting antiviral drug (DAA). Immunomodulator such as peginterferon-α or nucleos(t)ide analogues are two different comment strategies used in treating chronic hepatitis B. However, treatment of HBV/HCV co-infected patients is a great challenge. One of the viruses (HBV or HCV) will dominates and suppress another one. In recent studies, HBV reactivation was observed and proposed as a safety concern for DAA-treated HBV/HCV co-infected patients. The eradication of HCV with DAA may increase potential risk for HBV reactivation. AASLD recommends that treating HBV/HCV co-infected patients with DAA should be monitored at regular intervals. In addition, US FDA released black box warning about the risk of HBV reactivation during treatment with DAAs for HCV. How to prevent HBV reactivation is an important issue to be investigated.
Prior to the availability of DAA, the only standard of care for HCV infected patient is peginterferon-α plus fixed-dose ribavirin. High HCV SVR and HBsAg seroclearance rate were observed in a study treat HBV/HCV co-infected patients with traditional peginterferon-α/ribavirin therapy. Ropeginterferon alfa-2b (P1101) is a novel mono-pegylated recombinant proline-interferon alfa-2b with a 40kD branched polyethylene glycol chain being conjugated predominantly at its N-terminus. P1101 has only one major positional isomer, resulting in the purest pegylated interferon with an expected longer duration of action than Pegasys. In the results of phase II study, P1101 showed long-acting by every other week injection dosing frequency, comparing to every week injection duration of other pegylated interferon-alfa. To further access the inhibitory effect on HBV DNA reactivation, this study will address the great effect from longer P1101 treatment duration. The main objective is to evaluate a potential new therapy in reducing the incidence of HBV reactivation and diminishing morbidity in patients with HBV/HCV co-infection. The efficacy of combination of P1101 and Harvoni in reducing the risk of HBV reactivation and improving the rate of HBsAg loss will be examined.