For ethical reasons, clinical trials can only be carried out when the physicians do not know if a new treatment is effective in a particular disease. Enbrel has been tested extensively in the treatment of certain types of arthritis, and is approved by the Food and Drug Administration for use in rheumatoid arthritis and juvenile rheumatoid arthritis. Preliminary studies in WG have indicated that the use of Enbrel is safe in this disease, but its effectiveness is not known. A placebo is a liquid that looks like Enbrel but has no Enbrel in it. Both Enbrel and the placebo are given by injection under the skin twice a week.
Most patients learn to administer the medication themselves quite easily.
Others have a friend or family member administer the medication. In diseases as serious as WG often is, both the patients and the doctors want experimental treatments to work. This desire on the part of patient and doctor may bias the assessment of an experimental treatment's true effectiveness. The standard way of avoiding such bias is to assign some patients to the experimental treatment, and some to the placebo. This assignment is done randomly, by a computer.