Efficacy of pegfilgrastim and darbepoetin alfa as hematopoietic support for dose-dense every-2-week adjuvant breast cancer chemotherapy

Purpose Dose-dense, every-2-week adjuvant chemotherapy using doxorubicin/cyclophosphamide (AC; 60/600 mg/m(2) every 2 weeks X four cycles) followed by paclitaxel (175 mg/m(2) every 2 weeks X four cycles), requiring filgrastim on days 3 through 10 of each cycle has been shown to improve survival compared with every-3-week treatment schedules but is associated with greater risk of BBC transfusion (13%). The role of long-acting hematopoietic growth factors in facilitating every-2-week chemotherapy and minimizing hematologic toxicity has not been established. Patients and Methods Women with stage I to III breast cancer received dose-dense AC -> paclitaxel as neoadjuvant or adjuvant chemotherapy. Patients received pegfilgrastim 6 mg subcutaneous (SQ) on day 2 of each cycle. Darbepoetin alfa was initiated at 200 mu g SO every 2 weeks for hemoglobin <= 12 g/dL, and administered thereafter, according to a preplanned algorithm. The primary end points were to evaluate the percentage of patients with febrile neutropenia and the percentage of patients requiring BBC transfusion. Results Among 135 women treated on this single arm study, there were two cases of febrile neutropenia (incidence 1.5%). No patients received BBC transfusion. Darbepoetin alfa therapy was initiated in 92% of patients. The modest leukocytosis seen during paclitaxel cycles was attributable, in part, to corticosteroid premedication. Other toxicity and dose-delivery were similar to dose-dense AC -> paclitaxel in Cancer and Leukemia Group B 9741. Conclusion Pegfilgrastim and darbepoetin alfa are effective and safe in facilitating every-2-week AC paclitaxel, minimizing rates of febrile neutropenia and BBC transfusion.