Clinical evaluation and comparison of erythropoietic growth factors for chemotherapy-induced anemia (CIA)

Abstract

Background CIA is a significant problem in> 50% of cancer pts, impacting quality of life. Our objective was to evaluate & compare the use of epoetin (E) & darbepoetin (D) for CIA at our institution. Methods In this observational study, demographics, doses, hemoglobin (Hgb), transfusions, & chemotherapy use were followed× 12 wks in 108 adults (54 D, 54 E). By an intent to treat analysis, successful clinical response was defined as a Hgb (g/dL) increase≥ 2 or Hgb ≥12 at wk 12. Practice patterns were compared to clinical guidelines. Results The usual starting dose was 200 mcg QOW for D & 40K units Q7D for E. Demographics were similar between groups: mean (SD) age 52(1.4) yr, 57.8% female, 65.6% had solid tumors. Mean (SD) baseline Hgb was 10.2 (1.4) for D, & 10.0 (1.3) for E (p=0.3). At 12 wks, mean (SD) Hgb increase was: D, 1.1 (1.9); E, 0.8 (1.7), p=0.7. In all pts, the mean (SD) 12 wk Hgb was 11.0 (1.5); D, 11.4 (1.6); E, 10.7 (1.4) (p=0.04). The overall clinical response rate at the end of therapy was 38.9% (42.6% D, 35.2% E, p= 0.4). No dose changes occurred with D; 8 E pts were dose escalated. Therapy was rarely discontinued in non-responders. Conclusions The effectiveness of erythropoietic growth factors in clinical practice was lower than reported in clinical trials, due in part to underutilization of clinical guidelines & dose escalations. Both D & E provided equivalent responses in our population. Due to high cost of therapy, future plans are to implement a prospective monitoring program for use of these agents in our institution. Clinical Pharmacology & Therapeutics (2005) 77, P17–P17; doi: 10.1016/j.clpt.2004.11.068