Changes in iron parameters in patients (pts) with chemotherapy-induced anemia (CIA) receiving darbepoetin alfa (DA) every 3 weeks with and without intravenous iron supplementation

Abstract

19621 Background: There is growing interest in the use of intravenous (IV) iron supplementation in pts receiving erythropoiesis- stimulating agents (ESAs). We present an exploratory analysis of iron parameters in pts with CIA enrolled in a phase IIIb, randomized, open- label, study of DA administered with either IV iron or oral/no iron. Methods: Eligible pts had a non-myeloid malignancy and CIA (baseline Hb < 11g/dL). Pts received DA 500 mcg every 3 weeks (Q3W) using the Aranesp (darbepoetin alfa) prefilled SureClick autoinjector. Pts were randomly allocated (1:1) to receive either DA + 200 mg IV iron (200 mg Q3W with DA Q3W or two 100 mg doses within 3 weeks) or DA + oral/no iron. Randomization was stratified by tumor type and baseline Hb (< or = 10 g/dL). The primary endpoint was % pts achieving a hematopoietic response (Hb = 12 g/dL or increase = 2 g/dL). Results: 396 randomized pts received 1 dose of DA (IV-iron arm = 200; oral/no-iron arm = 196). Mean (SD) age was 61.0 (11.5) yrs; 61% (n = 240) were women; 28% (n = 111) had lung/gynecological tumors. Pt demographics were similar between arms. 44 (11%) pts had baseline iron deficiency (TSAT < 15%; serum ferritin < 100 μg/L); 5 (2%) in the IV iron arm and 23 (12%) in the oral/no-iron arm developed it. 141 (36%) pts had baseline functional iron deficiency (serum iron < 60 μg/dL; serum ferritin > 20 μg/L; TSAT < 20%); 54 (27%) in the IV arm and 67 (35%) in the oral/no-iron arm developed it. See table for iron parameters. Improved Hb-based responses in the IV-iron arm will be presented. Conclusions: Pts who received DA Q3W + IV iron appeared less likely to develop iron deficiency; iron deficiency may reduce responsiveness to ESAs. These pts also appeared to have a larger increase in mean serum ferritin levels. In contrast, mean serum iron, %TSAT, total iron binding capacity, and reticulocytes appeared to be similar in the 2 arms for most of the study period, suggesting that these iron parameters are not influenced by IV iron. No significant financial relationships to disclose. [Table: see text]