Propylactic Use of Entecavir for Biological Agents Associated Hepatitis B Virus Reactivation in Inflammatory Arthritis Patients: a Randomized Controlled Trial

The risk of HBV reactivation is associated with the intensity of immunosuppression. Biological therapies block the action of biological products involved in immune-inflammatory pathogenesis of many diseases. However, these biologic agents induce a profound immunosuppression, and their use has been reported to be associated with HBV reactivation. Currently, the actual incidence of HBV reactivation in inflammatory arthritis patients who underwent biologic treatments (TNF-α blockades) is unclear, especially in inflammatory arthritis (IA) patients with past hepatitis B infection. In this study, we plan to enroll IA patients who are inactive HBV carriers (HBsAg-positive/ HBV viral loads <2000 IU/ml; subgroup 1), or have past HBV infection (HBsAg-negative/anti-HBc-positive/ HBV viral loads < 2000 IU/ml; subgroup 2); and first line biologic treatment (Humira or Enbrel or Simponi or Orencia or Mabthera or Actemra) is indicated. Patients will be randomized in a 1:1 ratio to receive either prophylactic or therapeutic entecavir treatment for each subgroup. In the prophylactic group, participants will initiate entecavir 0.5 mg/day orally one week before biologic treatment. Entecavir treatment will be continued normally for 12 months. In the therapeutic group, patients will start entecavir therapy, 0.5 mg/day orally, when reactivation of HBV (pre-emptive treatment). HBV reactivation is defined as HBV viral loads > 2,000 IU/ml for 2 consecutive visits of one month apart. The main goal of the study is to delineate the incidence of HBV reactivation during and after biologic treatment in IA patients who are inactive HBV carriers or have past HBV infection, and tries to define the optimal HBV monitoring and antiviral prophylactic strategy in IA patients.