Weekly intravenous administration of recombinant human erythropoietin in infants with the anaemia of prematurity.

To study the safety and efficacy of administering human recombinant erythropoietin (rHuEPO) to infants with anaemia of prematurity, a combined phase I/II trial of weekly intravenous injections for 4 weeks was undertaken. We treated 16 infants with 10, 25, 50, 100 or 200 units/kg body weight in groups of two to four patients per dose level. They were all born prematurely (mean gestational age: 29 weeks; range 27-32), had a mean post-natal age of 42 days (range: 25-59) and haemoglobin concentration of 87 g/l (range: 72-94) when treatment was started. Four patients (25%) needed a transfusion during the trial, one at day 7 treated with 10 units/kg and 3 at days 15, 25, 29 with 100 units/kg. In the others, a progressive rise in mean haemoglobin values was seen in each group after 21 days of treatment, without a dose-dependent effect. A positive change in absolute reticulocyte counts with a peak after 7-14 days of therapy was observed with low (25-50 units/kg) but not with higher doses, with a significant difference at day 14 between 25 and 100 units/kg (P less than 0.01). A dose-limiting severe neutropenia (absolute neutrophil count less than 0.5 x 10(9)/l) occurred transiently in five patients, with doses greater than 25 units/kg. No infectious complication and no sign of iron deficiency were observed. Weekly low doses of rHuEPO appear safe, convenient to administer and able to induce a reticulocytic response in infants with anaemia of prematurity. A phase III placebo-controlled trial is needed to confirm these results. Neutropenia associated with rHuEPO administration in infants might be related to their stage of human ontogeny.