Recombinant human erythropoietin in the treatment of myelodysplastic syndromes--response patterns.

Different response patterns to recombinant human erythropoietin (rHuEpo) administration to anemic patients with myelodysplastic syndromes (MDS) are described. The biology of rHuEpo effect on erythropoiesis in patients with MDS has not been elucidated. However, until more biological information is obtained, it could be prudent to consider these response patterns as guidelines in the treatment of MDS. In the small but interesting series of nine patients with MDS only one responded to rHuEpo within the treatment period of eight weeks. Two additional patients continued the treatment on their own, and after 16 weeks a response was noted for the first time. A third patient was treated for only six weeks and a delayed response was recorded while off treatment for ten weeks. This response was also recorded 16 weeks from treatment initiation-as in the other two patients. A fourth patient with MDS developed transfusion related hemosiderosis and during iron chelation therapy the RBC transfusion rate dropped to a rate lower than the rate needed before the rHuEpo treatment. It is emphasized that in non responders, non-routine approaches should be considered.