As in previous years, throughout 1995 biologic agents have been explored and tested in open and controlled clinical trials with regard to their efficacy in treating autoimmune rheumatic diseases, especially rheumatoid arthritis. Promising data have been collected from a placebo-controlled double-blind four-center study of a monoclonal anti-tumor necrosis factor-alpha antibody in rheumatoid arthritis patients. This type of treatment was demonstrated for the first time to effectively interfere with ongoing inflammatory processes in this disease entity. That anti-tumor necrosis factor-alpha treatment principles are of clinical value has also been shown in open trials applying tumor necrosis factor receptor constructs. Although undoubtedly the progress in the development of biologic agents for the treatment of inflammatory rheumatic diseases is steadily improving, new and unexpected side effects must be carefully controlled.