Interim results from a Phase II, open-label study indicate that darbepotin alfa (Aranesp) 500 mcg appears to be well-tolerated and capable of increasing hemoglobin levels in patients with myelodysplastic syndrome. The 13-week results, for 189 out of 209 enrolled subjects, included erythroid response, achievement of target hemoglobin, incidence of transfusion and reported fatigue.

Of the 189 subjects, 130 had not previously used an erythropoietin drug. Of those who had had no prior erythropoietic treatment, 70 percent achieved an erythropoietin response, and 49 percent of these had a major response, defined as a 2-g/dL or more increase from baseline hemoglobin or transfusion independence.

Results show that 67 percent of evaluable subjects achieved the target hemoglobin of 11 g/dL, and 19 percent in the erythropoietin-naive group received at least one transfusion during the 13 weeks of observation.