At a recent presentation at the 2005 annual meeting of the American Society of Clinical Oncology, researchers revealed that the drug Revlimid is highly effective in the treatment of transfusion-dependent myelodysplastic syndromes (MDS).

MDS is a group of disorders that are characterized by a low blood count that is due to bone marrow dysfunction. MDS may arise spontaneously or may be attributed to chemotherapy or radiation therapy for the treatment of other diseases, which is known as secondary MDS. In general, secondary MDS has a worse prognosis than MDS that arises without cause. In approximately 30% of cases, MDS will convert to acute myeloid leukemia. Supportive care has been the mainstay of treatment, with judicious use of blood and platelet transfusions as needed to improve outcomes. One type of MDS involves a missing or defective gene, which accounts for 18-25% of all patients with MDS. In general, these patients require frequent blood transfusions and respond poorly to other types of drugs that stimulate the immune system and boost the production of red or white blood cells and platelets.

Revlimid is a new drug that is considered to be an immunomodulatory drug (iMID) that is a derivative of thalidomide. Immunomodulatory drugs work by either modifying or regulating the immune system. iMIDS appear to have multiple functions such as anti-cancer and anti-inflammatory activities. Previous studies have shown that patients with the type of MDS that involves the missing or defective gene have responded extremely well to Revlimid, required fewer transfusions and experienced improved blood counts.

This recent study involved 148 patients who had either low- or intermediate-risk MDS and were dependent on regular blood transfusions. Of these patients, 86% had a genetic alteration associated with MDS. The average patient had an average duration of MDS of 3.4 years. The study was designed to evaluate the efficacy of Revlimid by evaluating patients’ ability to sustain without transfusions (transfusion independence) for 56 days. The results indicated that 66% of patients achieved transfusion independence for an average of 47 weeks. Increases in the patients’ hemoglobin (red blood cell count) were achieved in an average time of only 4.4 weeks. Genetic changes were noted in 70% of patients, and were associated with a response in the patients’ blood counts. The most serious side effects resulting in a reduction in treatment or a delay in treatment included a drop in the white blood count and decreased platelet counts.

Researchers concluded that Revlimid appears to be one of the most promising treatments for patients with MDS who are transfusion dependent. Response to Revlimid was shown to be quick and long lasting in this group of patients, as well as being generally well tolerated.

Reference: List A, Dewald G, Bennett J, et al. Hematolgoic and cytogenetic (CTG) response to lenalidomide (CC-5013) in patients with transfusion-dependent (TD) myelodysplastic syndrome (MDS) and chromosome 5q31.1 deletion: Results of a multicenter MDS-003 study. Proceedings from the 2005 annual meeting of the American Society of Clinical Oncology (ASCO). Presented May 14, 2005 at a plenary session. Abstract #5.