Comparison of Prophylactic Antiviral Efficacy in Patients Undergoing Chemotherapy: Entecavir Versus Lamivudine

• The cumulative probability of HBV reactivation [ Time Frame: From the time of randomization until 24week after discontinuation of antiviral prophylaxis ] [ Designated as safety issue: No ]
  10-fold or more elevation in serum HBV DNA titers above nadir
  
  

• Incidence of HBV-related hepatitis flare [ Time Frame: From the time of randomization until 24week after discontinuation of antiviral prophylaxis ] [ Designated as safety issue: No ]
  greater than 3-fold increase of ULN (upper limit of a normal reference value) of a serum ALT level that exceeded 100 IU/L during antiviral prophylaxis and 24 week after discontinuation of antiviral prophylaxis
  
  
• Cumulative probability of emergence of genotypic resistance [ Time Frame: From the time of randomization until 24week after discontinuation of antiviral prophylaxis ] [ Designated as safety issue: No ]
  detection of mutations that have been shown in in vitro studies to confer resistance to either ETV or LAM
  
  
• Incidence of hepatic decompensation and liver-related mortality [ Time Frame: From the time of randomization until 24week after discontinuation of antiviral prophylaxis ] [ Designated as safety issue: No ]
  

Chronic hepatitis B virus (HBV) carriers who are undergoing anticancer chemotherapy are at risk of HBV reactivation and hepatitis flare, and lamivudine (LAM) prophylaxis is recommended according to the practice guidelines despite of limited evidence. However, failure of LAM prophylaxis defined as virologic breakthrough during LAM therapy and withdrawal hepatitis after discontinuation of LAM therapy occurs occasionally, which may lead to liver-related morbidity and mortality as well as premature interruption or a delay of chemotherapy. Considering that LAM therapy showed relatively higher rates of drug resistance and of withdrawal hepatitis, studies on the better choice of prophylactic antiviral regimen is warranted.

The purpose of our study is to conduct a multicenter, prospective, randomized study comparing the effect of entecavir (ETV) versus LAM for the prevention of HBV reactivation in HBsAg-positive patients with hematologic and oncologic malignancy undergoing cytotoxic chemotherapy.

A total one hundred eighty HBV carriers with malignancy undergoing chemotherapy will be randomly assigned to each prophylactic therapy arm of ETV and LAM group. The primary endpoint of the study is the HBV reactivation rate during antiviral therapy and 6 months after discontinuation of prophylactic antiviral therapy.

If the prophylactic efficacy of ETV is superior to that of LAM, ETV will be the preferred prophylactic therapy for HBsAg-positive cancer patients undergoing chemotherapy.