COLUMBIA, South Carolina—A dose escalation trial of darbepoetin alfa(Drug information on darbepoetin alfa) (Aranesp) found the new erythropoietic agent can boost hemoglobin rates in most cancer patients with chronic anemia, a group not usually treated with erythropoietic therapy (ASCO abstract 1465).

The multicenter investigation led by Robert E. Smith, MD, president of South Carolina Oncology Associates in Columbia, focused on patients who were not receiving concomitant chemotherapy or radiation. The sole erythropoietic agent approved for treating anemia in cancer patients, epoetin alfa(Drug information on epoetin alfa) (Procrit), is indicated for patients undergoing chemotherapy for nonmyeloid malignancies.

Yet anemia is common in patients who are not receiving chemotherapy or radiation treatments, according to Dr. Smith and his co-investigators. Previous studies suggest anemia could be the result of reduced red blood cell survival, relative deficiency of endogenous erythropoietin(Drug information on erythropoietin), or blunted erythropoietic response.

Dose Escalation

All 188 patients in the pilot study had hemoglobin levels of 11 g/dL or less at the outset. Their cancers included breast, prostate, gastrointestinal, lung, gynecologic, and other primary tumors. None of the patients had received chemotherapy or been treated with erythropoietic therapy in the 8 weeks prior to the trial, but patients may have had up to two red blood cell transfusions within 4 weeks of enrollment. Participants also could not expect to receive chemotherapy or external beam radiotherapy within 16 weeks of enrollment.

The first 102 patients were injected weekly with darbepoetin alfa in sequential doses of 0.5, 1.0, 2.25, or 4.5 µg/kg for the 12 weeks of the study. Hematopoietic response was defined as an increase in hemoglobin of 2 g/dL or greater or reaching a hemoglobin level of 12 g/dL or more. The hematopoietic response rate hovered around 70% for the 1.0 and 2.25 µg/kg doses, and reached 100% at the top dose (see Table 1). "I don’t think anything has shown a 100% response rate," Dr. Smith said, referring to previous studies.

Frequency of Administration