Abatacept vs Placebo in RA Patients With Hepatitis B on Entecavir Background

Rheumatoid arthritis (RA) is a chronic, systemic inflammatory disorder affecting 1% of the world's population. If not adequately controlled, it may lead to disability in up to 30% of patients within the first three years of disease onset \[1\] and can be associated with premature death. Recent research has suggested that the first event in the pathogenesis of RA is an antigen dependent activation of T-cells in an immunogenetically susceptible host. T-cells require two signals for activation, one involving the trimolecular complex (class II Major Histocompatibility Complex (MHC), antigen, T-cell receptor), and the other being co-stimulation of the CD28 (Cluster of Differentiation 28) molecule on T-cells by the B7 molecules (CD80 and CD86) on antigen presenting cells. Hepatitis B virus (HBV) can cause chronic disease in 5% of immunocompetent adults and has a prevalence of over 350 million worldwide. It is a leading cause of chronic hepatitis, cirrhosis and hepatocellular cancer and accounts for one million deaths annually. In patients with chronic hepatitis B and RA, treatment options are limited. Traditional disease modifying anti-rheumatic drugs (DMARDs) are associated with hepatotoxicity and are contraindicated in chronic hepatitis. A recent retrospective analysis suggests that successful use of anti-tumor necrosis factor alpha (anti-TNF) agents may be possible in these patients but the authors do warn that these patients should be closely monitored and that fatal reactivation of hepatitis B is possible. Treatment with rituximab, a chimeric monoclonal antibody against B-cell protein CD20, is another option; however, the use of this medication in RA patients with chronic hepatitis B may also cause reactivation. When RA patients with chronic hepatitis B were started on a Tumor Necrosis Factor (TNF) inhibitor or methotrexate (MTX), 2 of 5 HBsAg+ patients reactivated their hepatitis B, indicating a possible high rate of activation in these patients when not on hepatitis B treatment. Reactivation in this and another study occurred after 9-19 months of antirheumatic therapy. In RA patients with chronic Hepatitis B, entecavir appears to be effective at preventing reactivation. There are no studies on the safety of abatacept in patients with RA and HBV. Adequate T-cell function is important to help cure or contain HBV infection. Our site has conducted a retrospective study that shows preliminary safety of abatacept in patients with RA and chronic Hepatitis B on antiviral therapy. The purpose of this study is to assess the safety and efficacy of abatacept in RA patients with chronic Hepatitis B in a pilot study in a randomized, controlled fashion.