According to a recent article published in the British Journal of Haematology, prolonged administration of erythropoietin may provide better results compared to shorter courses in patients with myelodysplastic syndrome.

A myelodysplastic syndrome (MDS) is a disease in which the cells in a person’s bone marrow are not functioning normally. The bone marrow (and circulating blood) contains early blood-forming cells called stem cells, which grow and mature into the 3 blood cell types: white blood cells, which protect the body from infection; red blood cells, which carry oxygen to the tissues; and platelets, which help the blood to clot. In the case of MDS, not enough normal blood cells are being produced and/or the blood cells die prematurely. This condition is sometimes referred to as a pre-leukemia or “smoldering” leukemia because it often develops into leukemia, a type of cancer. Some patients with MDS also have additional abnormalities, including genetic abnormalities of the blood cells, a high number of immature blood cells (called blasts) in the bone marrow, or decreasing numbers of red blood cells, white blood cells, or platelets. These individuals are at a higher risk for a more rapid progression to leukemia than are those who have more favorable cell features. There are five different stages, or extent, of MDS that include (in order of disease progression) refractory anemia, refractory anemia with ringed sideroblasts, refractory anemia with excess blasts, refractory anemia with excess blasts in transition and chronic myelomonocytic leukemia.

Treatment of MDS often consists of the infusion of red blood cells or platelets to compensate for the inadequate production of these cells in the bone marrow. This therapy may ease the signs and symptoms of disease, such as anemia or fatigue, and may prolong survival time. However, transfusions may be associated with cost, discomfort, inconvenience, infection and rejection of donor cells. Researchers are investigating novel therapies for patients with MDS.

Erythropoietin (EPO) is a substance naturally produced by the kidneys that stimulates the bone marrow to produce and mature red blood cells. Several trials have shown an approximate 20% response rate in patients with MDS treated with EPO that has been produced in a laboratory.

Researchers from the Greek MDS Study Group recently conducted a clinical trial to determine if prolonged administration of EPO may improve response rates in patients with MDS. This trial involved 281 patients with varying stages of MDS who were treated with EPO and evaluated at 12 and 26 weeks of treatment. The response rate significantly increased at 26 weeks of treatment, compared to responses at 12 weeks of treatment. The overall response to EPO at 26 weeks was 45.1%, with specific responses being 48.3% for refractory anemia, 58.4% for refractory anemia with ringed sideroblasts, 33.8% for refractory anemia with excess blasts of less than 10% and 13% for patients with refractory anemia with excess blasts between 11%-20%. The average duration of response was 68 weeks and the risk of transformation to leukemia was 21.7%. The response rate was also higher in patients with favorable cytogenetics and higher levels of EPO in the blood prior to therapy.

These authors concluded that prolonged duration of EPO improved responses in patients with MDS, particularly those with low blast levels. Patients with MDS receiving EPO may wish to speak with their physician about the risks and benefits of prolonged treatment with EPO, compared to a shorter course of therapy, or participation in a clinical trial evaluating other novel therapeutic approaches. Sources of information regarding ongoing clinical trials include the National Cancer Institute ( cancer.gov).

Reference: Terpos E, Mougiou A, Kouraklis A, et al. Prolonged administration of erythropoietin increases erythroid response in myelodysplastic syndromes: a phase II trial in 281 patients.

British Journal of Haematology. 2002;118:174-180.