A Randomized Comparison of Standard Weekly Epoetin Alfa to Every-3-Week Epoetin Alfa and Every-3-Week Darbepoetin Alfa: A Study of the Mayo Clinic Cancer Research Consortium (MCCRC)

Abstract 3008 Poster Board II-984 Introduction: The erythropoiesis-stimulating agents (ESAs) epoetin alfa (EA) and darbepoetin alfa (DA) increase hemoglobin (Hb) levels and reduce red blood cell (RBC) transfusion requirements in patients (pts) with cancer chemotherapy-associated anemia (CAA). Extended-interval ESA dosing (i.e., administration less than once weekly) is a common practice with DA, which is FDA approved for dosing once every 3 weeks (q3wks); a previous study of the North Central Cancer Treatment Group suggested that EA can also be given less often than the FDA-approved once weekly schedule (Steensma DP et al, J Clin Onc 2006; 24:1079). The present study compared 2 different q3wks extended-interval EA regimens with weekly fixed-dose EA and with q3wks DA in pts with CAA. Patients and Methods: Eligible pts were receiving chemotherapy for a non-myeloid malignancy and had Hb 20 ng/mL, weight >40 kg and 12 g/dL and restarted at a lower dose when Hb fell to '11.5 g/dL. All pts received ferrous sulfate 325 mg orally once daily, if tolerated. Quality of life (QOL) was measured using the Symptom Distress Scale (SDS), Brief Fatigue Inventory (BFI), FACT-An, and Linear Analogue Self Assessment (LASA) tools. The primary endpoint was the proportion of pts achieving Hb≥11.5 g/dL or increment of Hb>2.0 g/dL from baseline. Secondary endpoints included RBC transfusion requirements, adverse events (AEs), and QOL. Results: 239 pts (236 evaluable) enrolled at 10 MCCRC sites between Feb. 2007 and Dec. 2008; 62% of pts completed all study interventions. The median age of enrolled pts was 66 years; 42.4% were men, 91.5% had solid tumors, 26.7% had severe anemia (Hb 0.41 for all comparisons), but the median Hb increment from baseline was higher in the 40K and DA arms compared to the 2 extended dosing EA arms (40K-2.8 g/dL, 80K-2.0 g/dL, 120K-2.1 g/dL, DA-2.6 g/dL; p=0.005 for 40K vs 80K). Hb response was achieved more quickly in the weekly EA arm, but the difference was not significant (40K-32 days, 80K-50 days, 120K-49 days, DA-49 days; p>0.13). The proportion of patients transfused was similar between arms (40K-27.9%, 80K-33.3%, 120K-22.4%, DA-29.8%; p>0.49). There were no significant differences in QOL changes. Deaths were also similar between arms (40K-5 pts, 80K-7 pts, 120K-7 pts, DA-1 pt, p>0.10) and were primarily due to disease progression. AEs and serious AEs were comparable between study groups; grade 3/4 AEs were observed in 22% of pts in the 40K arm, 22% on 80K, 17% on 120K, and 13% on DA; p>0.56. The median total dose of EA used was highest in the 120K arm (40K-265,000 U; 80K-240,000 U; 120K-360,000 U; p=0.0009 for 40K vs 120K), while pts on the 40K arm were more likely to omit a dose due to a high Hb (40K-63.9% of pts omitted at least one dose; 80K-30.0%; 120K-34.5%; DA-43.6%, p Conclusion: Although there was no significant difference in the proportion of responding pts (the primary endpoint), Hb increments from baseline were moderately higher with the 2 FDA-approved regimens – weekly EA 40,000 Units, and q3wk DA 500 mcg – than with the extended dosing regimens. This study was supported by a grant from Centocor Ortho Biotech, Inc. to the MCCRC. Disclosures: No relevant conflicts of interest to declare.