Subcutaneous erythropoietin for treatment of refractory anemia in hematologic disorders.

We have used recombinant human erythropoietin (rHuEPO) in a phase 1/11 clinical trial to evaluate its ability to reverse refractory anemia in hematologic disorders. rHuEPO was administered subcutaneously 5 days per week at escalating doses (50 t o 150 U/kg per day). The aim of treatment was a hemoglobin (Hb) level 2 10 g/dL without blood transfusion. Of 25 patients treated, 17 were evaluable, most of them with a regular need for transfusion. Eight of these had lymphoproliferative disorders (three cases of malignant lymphoma and five of monoclonal gammopathy) and were exposed t o cytotoxic therapy. The other nine patients had hematopoietic stem cell disorders (four cases of myelodysplastic syndrome, three of idiopathic myelofibrosis, and two of chronic myelogenous leukemia). All patients with lymphoproliferative disorder had serum EPO levels inappropriately low for the degree of anemia, while patients with stem cell disorder showed variable values. Erythroid marrow activity was inadequate in all cases. Seven of eight patients with lymphoproliferative disorder responded t o treatment maintaining Hb above 10