Currently it is approved by the U.S. Food and Drug Administration (FDA) for use in treating a skin disease associated with leprosy. Thalidomide is being studied, either as a single agent or in combination with other medicines, for treating of myelodysplastic syndromes (MDS). These clinical trials are studying the effectiveness and safety of the drug. A pilot study of thalidomide, published in 2001, found the drug improved blood counts in some patients and enabled others to become transfusion-independent. Thalidomide has some severe side effects which may limit its application as a treatment for MDS.