Speed of haemoglobin response in patients with cancer: a review of the erythropoietic proteins.

BACKGROUND: Patients with cancer-related anaemia generally have a poor prognosis. Evidence suggests that an effective erythropoietic protein (epoetin)-mediated haemoglobin (Hb) response provides marked improvement in quality of life (QoL). An early Hb response to erythropoietic protein therapy in these patients would appear ideal but few studies have compared the speed of response to different erythropoietic proteins, or the potential benefits associated with an early Hb response. RESULTS AND DISCUSSION: The pharmacokinetic/pharmacodynamic profiles of commercially available erythropoietic proteins are reviewed along with available clinical data to examine Hb response and associated clinical outcomes for each of these agents. Randomised, head-to-head trials comparing epoetin alfa and darbepoetin alfa suggest that patients administered with epoetin alfa achieve a satisfactory Hb response significantly earlier than those given darbepoetin alfa, and with consistently lower monthly transfusion rates. Non-comparative studies support this, suggesting also that epoetin beta may provide a relatively faster Hb response in a greater number of patients than either epoetin alfa or darbepoetin alfa, irrespective of malignancy or chemotherapy type. Moreover, studies suggest consistently that a 'front-loading' dosing regimen with epoetin alfa does not convey improved speed of Hb response over epoetin beta administered according to current clinical practice guidelines.
CONCLUSIONS: Given the poor prognosis of anaemic patients with cancer, the use of an agent which provides clinical benefits quickly but with minimal thromboembolic risk, should be considered an essential component of anaemia management in these patients. However, more head-to-head studies are required to confirm the relative efficacy of currently available erythropoietic proteins.