Once weekly recombinant human erythropoietin therapy is very efficient after allogeneic peripheral blood stem cell transplantation when started soon after engraftment.

A, et al. What happens subsequently in AML when cytoge-neetic abnormalities persist at bone marrow harvest? Results of the 10 th UK MRC AML trial. We enrolled 13 recipients of an allogeneic peripheral blood stem cell transplant (PBSCT) in a trial of recombinant human erythropoietin (rHuEpo) therapy (500 U/kg/wk once weekly) started on day 30 after PBSCT. Ten patients who did not receive rHuEpo served as controls. The overall probability of achieving a hemoglobin level >13g/dL was 91% in rHuEpo-treated patients versus 14% in controls (p=0.0001). We recently showed that recombinant human erythropoi-etin (rHuEpo) therapy was very efficient when the therapy was started 35-1444 days after an allogeneic hematopoietic stem cell transplant. 1 In this study, we first studied endogenous ery-thropoietin production in a cohort of 10 allogeneic peripheral blood stem cell transplant (alloPBSCT) recipients (control group) with the aim of defining the best time to start rHuEpo therapy after alloPBSCT. We then enrolled 13 alloPBSCT recipients in a trial of recombinant human erythropoietin (rHuEpo group) therapy at a dose of 500 U/kg/wk, given once a week (qw) starting on day 30 after PBSCT (Table 1) with the aim of achieving hemoglobin levels of 13 g/dL (complete response). Results were compared with those in a group of 13 similar patients 1 receiving rHuEpo at the same dose given thrice weekly starting on day 35 after PBSCT (historical group). The trigger for packed red blood cell transfusions was a hemoglobin (Hb) 8 g/dL for all patients receiving rHuEpo and 8 g/dL (N=6) or 9 g/dL (N=4) for patients included in the control group. One of 13 patients in the rHuEpo group, 2/13 in the historical group (p=NS) and 4/10 in the control group (p=NS) had a major ABO incompatibility with their donor. Once the target Hb had been achieved, the dose of rHuEpo was reduced so as to use the lowest dose capable of maintaining the Hb between 12 and 14 g/dL. Laboratory as well as statistical analyses were carried out as previously reported. 2-5 After PBSCT, serum erythropoietin levels peaked on day 0 with a mean observed-to-predicted (O/P) erythropoietin 6 of 1.15±0.09 (p=0.03 compared with O/P Epo in 31 healthy donors) (Figure 1A) but became inappropriately low for at least 6 months thereafter. After two weeks of treatment, transfusion independence was achieved in 12/13 (92%) patients in the rHuEpo group, 11/13 (85%) in the historical group (p=NS) and 5/10 (50%) …