Monoclonal antibodies and other biologic therapies

The treatment of systemic lupus erythematosus (SLE) presents a significant therapeutic challenge: multi-organ involvement and a variable disease course characterized by clinical exacerbations and remissions make it difficult to predict outcome. Few products have been specifically developed in this clinical indication and most accepted therapies have not been tested in randomized controlled trials in SLE. A variety of biologic agents under investigation as potential treatments for SLE are designed to interfere with specific immunologic responses, hopefully avoiding generalized immunosuppression. These include therapies to downregulate IL-10 and/or upregulate TGFb production. Agents which interfere with T cell activation and T cell-B cell collaboration, such as CTLA4-Ig and anti-CD40 ligand monoclonal antibodies, may result in long term therapeutic benefit; alone or in combination, even following brief treatment courses. Products designed to decrease production of anti-dsDNA antibodies or inhibit complement activation may prevent immune complex deposition and amerliorate organ-specific manifestations such as renal disease. More aggressive interventions include gene therapy and stem cell transplantation. As these agents enter clinical trials, efforts to develop international consensus regarding trial methodology and outcome measures will be crucial to their successful development.