Objectives. Rheumatoid arthritis (RA) is characterized by the chronic inflammation of the synovial joints resulting from the hyperplasia of synovial cells and the infiltration of lymphocytes, macrophages and plasma cells. Currently, the aetiology of RA is not known, and new treatment modalities are needed to prevent the disease progression. Apoptosis induction of synovial cells through the use of death ligands has been explored as a treatment modality for RA. Thus, the primary objective of this study was the testing of the efficacy of adenovirus delivery of human TRAIL (Ad5hTRAIL) for the treatment of patients with RA.