Amifostine in the treatment of low-risk myelodysplastic syndromes.

Background and Objectives. The phosphorylated aminothiol agent amifostine (Ethyol) protects bone and other tissues from toxicity due to ionizing radiation and antineoplastic drugs, and stimulates progenitors from normal and myelodysplastic marrow. Contrasting results have been published so far on the effectiveness of amifostine in ring cytopenia in patients with myelodys-plastic syndromes (MDS). Design and Methods. In a pilot phase II study we treated 26 patients with low risk MDS (13 RA, 2 RARS, 2 CMML, 9 RAEB with blasts < 10%) with amifostine (200 mg/m(2) x 3/week for 4 weeks). Results. Hemoglobin concentration, reticulocyte, neutrophil and platelet counts increased respectively in 6 (23%), 11 (42%), 13 (50%) and 9 (34%) of patients. Red cell transfusions were reduced (> 50%) in 4/26 patients and abolished in 1/26. Unexpectedly a significant decrease in soluble transferrin receptor level at week 4 of therapy, compared to the basal level (p<0.04), was observed in the whole population of patients. Interpretation and Conclusions. Amifostine can ameliorate cytopenia in some patients with MDS, with few and mild side effects. Neutropenia is more likely to be corrected than anemia or thrombocytopenia. Mechanisms underlying this biological remain to be clarified.