Treatment of myelodysplastic syndromes (MDS) and high leukaemic risk with low-dose cytosine arabinoside (LD-AraC) plus granulocyte-macrophage colony-stimulating factor (rh GM-CSF). The EORTC Leukaemia Group.

Symptomatic patients with myelodysplastic syndromes (MDS) and 10-30% blasts in the bone marrow were treated with low-dose AraC (2 x 10 mg/m2 subcutaneously (sc) days 1-14) and GM-CSF (fully glycosylated, Sandoz/Schering-Plough, 2 x 150 micrograms protein/day sc) given either subsequently (days 15-21) or simultaneously (days 8-14 and one week rest). Evaluations were carried out after three courses (nine weeks); responding patients could be continued for two further cycles. Eighty-two patients with refractory anaemia and excess of blasts (RAEB), with (RAEBt) or without transformation, were evaluable: 45 RAEB and 37 RAEBt, mean age 64 years (range 17-80 years). A complete remission was achieved in 14 cases (17%), 11 had a good response (13%), and 12 a partial response (15%). Stable disease was found in 21 cases (26%). There were 12 cases of toxic death (15%), progression was noted in eight patients (10%), and death due to disease in three (4%). No difference existed between the two treatment arms with respect to response. Major adverse events during treatment were haemorrhage (25%), infections (23%), and fever with GM-CSF (21%). GM-CSF did not induce leukaemia nor contribute to haemorrhage induced by AraC, but gave rise to an overall response rate of 46% which is high and relatively durable as compared to other treatments in this disease.