OBJECTIVES: I. Assess the therapeutic activity of monoclonal antibody HuG1-M195 on peripheral blood and bone marrow blast cell count, blood leukocyte, reticulocyte, and platelet counts, and hemoglobin levels in patients with myelodysplastic syndrome with refractory anemia with excess blasts (RAEB) (greater than 10% bone marrow myeloblasts) or RAEB in transformation. II. Assess the efficacy of this drug in terms of duration of response in these patients. III. Evaluate the toxicity of this drug in these patients.