Darbepoetin alfa Administered Every 3 Weeks Is Effective in Correcting Hemoglobin and Reducing Transfusion Requirements in Anemic Patients with Hematological Malignancies Receiving Chemotherapy: A Retrospective Observational Study Reflecting Real-World Clinical Practice in Europe.

Abstract

Introduction: Observational research provides valuable comparative information about the use and effect of drugs in a particular patient (pt) population (eg, pts with hematological malignancies) in real-world clinical practice, which may be different from those in controlled clinical studies.Methods: This multicenter study of medical records evaluated use of darbepoetin alfa (DA) 500 mcg every 3 weeks (Q3W) in anemic pts with nonmyeloid malignancies receiving chemotherapy treatment in 7 European countries (Denmark, France, Germany, Greece, Spain, Sweden, and Switzerland). Data were collected on a retrospective basis using medical record review and a standard case report form. Data related to adverse events or other measures of safety were not collected. The analysis included pts who either completed the observational period (≤16 weeks) or stopped treatment but received ≥1 DA dose. Pts had to be ≥18 years old, start DA treatment after 01January2004, and provide informed consent (if needed by country regulations). Descriptive statistics were generated. In this posthoc analysis, a subset analysis was performed by tumor type: hematologic malignancies, solid tumors, and all pts. Percentages of pts with hematopoietic response (hemoglobin [Hb]≥12g/dL and/or 2-g/dL increase from baseline to end of treatment period), transfusion, and Hb ≥11 g/dL were evaluated.Results: 391 pts received DA, of whom 64 (20%) had hematologic malignancies. Overall, most pts were women (60%) and white (97%), with a mean (SD) age of 62.5[11.8] yrs and a mean baseline Hb of 9.7[0.9] g/dL. Most pts received concomitant chemotherapy (99%). No pts discontinued treatment due to side effects. In pts with hematologic malignancies, treatment with DA 500 mcg Q3W increased Hb levels above 11 g/dL in 73% of patients and left 69% of pts transfusion free (Table). These results were similar in pts with other tumor types and in all pts in this study, as well as in pts with lymphoproliferative malignancies enrolled in previously reported phase 3 clinical trial of the DA QW treatment schedule (Table).TableOutcomesReal-world Study (DA 500mcg Q3W)Phase 3 StudyKaplan Meier proportions of patients (95% Confidence Intervals) #Hematologic Malignancies (n=64)Other Tumors (n=261)All Pts (n=325)DA 2.25 mcg/kg QW (n=174)Placebo (n=170)Hematopoietic response59%(44–73)68%(60–75)66%(59–73)65%(57–73)24%(72–81)Hemoglobin ≥11g/dL during study73%(61–85)85%(78–92)78%(71–85)NRNRAt least 1 transfusion (week 5 to end of treatment period)31%(18–44)22%(16–29)24%(19–30)31%(24–38)48%(41–56)NR=not reported; #=Based on effectiveness analysis set. Phase 3 Study = Hedenus et al, Brit J Haematol 2003; 122; 394.Conclusion: Based on these results, DA 500 mcg Q3W in real-world clinical practice in Europe exhibited similar effectiveness compared with outcomes observed in clinical trial setting. In this study, DA 500 mcg Q3W appeared to be effective in treating anemia in pts receiving chemotherapy, regardless of tumor type.