Darbepoetin Alfa (Aranesp): Alternative Name and Clinical Information
Darbepoetin alfa is also known as Novel Erythropoiesis-Stimulating Protein (NESP). This alternative name is documented in clinical practice guidelines from the American Society of Hematology (ASH) and American Society of Clinical Oncology (ASCO) 1.
Mechanism and Pharmacology
Darbepoetin alfa is an amino acid substituted analog of human erythropoietin that:
- Promotes erythrocyte survival, proliferation, and differentiation 2
- Has a threefold longer terminal half-life than recombinant human erythropoietin (epoetin) 3
- Contains a higher number of sialic acid moieties resulting in prolonged half-life and enhanced biological activity 4
- Has a mean terminal half-life of approximately 25.3 hours after intravenous administration and 48.8 hours after subcutaneous administration 5
Clinical Equivalence with Epoetin
According to the 2007 ASH/ASCO clinical practice guideline update:
- Darbepoetin alfa and epoetin are considered equivalent with respect to effectiveness and safety in treating anemia in patients with cancer 1
- This equivalence is based on comprehensive systematic reviews comparing outcomes in patients with chemotherapy-induced anemia 1
- Both agents have identical cancer-related indications, warnings, and cautions in their FDA-approved package inserts 1
Dosing Advantages
Darbepoetin alfa offers dosing advantages over conventional epoetin:
- Can be administered less frequently (once weekly or once every 2-3 weeks) compared to epoetin (typically three times weekly) 6
- Maintains hemoglobin levels as effectively as epoetin despite reduced dosing frequency 3
- The extended dosing interval can be synchronized with most chemotherapy regimens, providing greater convenience 4
Safety Considerations
Important safety considerations for darbepoetin alfa include:
- Increased risk of thromboembolic events in cancer patients (50-75% higher than placebo) 7
- Doubled stroke risk (both ischemic and hemorrhagic) when targeting higher hemoglobin levels (130 g/L) compared to lower targets (90 g/L) in patients with chronic kidney disease and diabetes 1
- Similar adverse event profile to epoetin with no evidence of antibody formation to the drug in clinical trials 5
Clinical Applications
Darbepoetin alfa is FDA-approved for:
- Treatment of anemia associated with chronic kidney disease 2
- Treatment of chemotherapy-induced anemia in cancer patients 4
When considering darbepoetin alfa therapy, clinicians should carefully weigh the risks of thromboembolism, particularly in patients with established risk factors such as previous history of thromboses, surgery, and prolonged periods of immobilization 1.
Healthcare providers should follow FDA guidelines for starting doses (2.25 μg/kg weekly or 500 μg every 3 weeks) and confirm hemoglobin <10 g/dL before initiating therapy 7.