Darbepoetin versus epoetin alfa for the correction of anemia in cancer patients receiving radiotherapy or chemoradiotherapy treatment.

Abstract

Introduction: Anemia is the most frequent hematological disturbance in cancer patients, with prevalence between 30% and 90%, depending on the type of tumor, the antitumor treatment, and other factors (infection, malnutrition, bleeding, tumor infiltration of the bone marrow). A number of erythropoietic agents have shown to be effective in increasing the hemoglobin (Hb) levels, reducing the requirements for transfusion, and improving quality of life. The objective of this study is to compare darbepoetin alfa and epoetin alfa when used to correct anemia in cancer patients who are receiving radiotherapy or radiochemotherapy.

Material and methods: A prospective study of 125 consecutive patients with anemia (Hb <13 g/dL in males or <12 g/dL in females) who were undergoing treatment with radiotherapy (RT) or radiochemotherapy (RCT) in our department were enrolled between March 2003 and March 2005. The treatment for the anemia was either darbepoetin alfa 150 mcg/week (62 patients, group 1) or epoetin alfa 40,000 IU/week (63 patients, group 2). Patients received iron supplements in both groups. Treatment was administered in a consecutive manner depending on tumor type. If the increase in Hb was <1 g/dL after 4 weeks of treatment, the dose was increased to 300 mcg/week in group 1 or to 60,000 IU/week in group 2. The treatment was terminated when a Hb value of ≥15 g/dL was reached during RT treatment, a Hb value of ≥14 g/dL was reached if the RT had been completed, or after 16 weeks of treatment whatever the Hb value. The mean age of patients was 63.36 ± 11.27 years, 67% were male. No significant differences were observed between the 2 groups in tumor type or stage, previous treatments, or intent to treat with RT or RCT.

Results: Comparing group 1 and group 2 by intent to treat, the mean Hb at the start of treatment with the study drug was 12.1 g/dL vs 11.8 g/dL, the proportion of patients whose dose was increased was 19.7% vs 24.6%, the need for transfusion was 3.2% in each group, the duration of erythropoietic treatment was 6.5 weeks in both groups, and 2 patients in group 2 restarted treatment with epoetin alfa. The percentage of patients who responded (defined as an increase in the Hb ≥ 2 g/dL in the absence of transfusions) was of 72.6% and 66.7%, respectively. Four vascular adverse events were observed, 2 in each group. No significant differences were observed with respect to the baseline, week 4, and week 12 levels of endogenous erythropoietin, serum iron,% saturation, and ferritin. The increase in Hb 1 month after the final administration of the study drug was 2.21 g/dL in group 1 and 2.46 g/dL in group 2 (p = ns).

Conclusions: The results of our study demonstrate that both treatments are equally effective in correcting anemia in cancer patients undergoing RT or RCT.