Blinded, randomized, multicenter study to evaluate single administration pegfilgrastim once per cycle versus daily filgrastim as an adjunct to chemotherapy in patients with high-risk stage II or stage III/IV breast cancer

Purpose: This multicenter, randomized, doubleblind, active-control study was designed to determine whether a single subcutaneous injection of pegfilgrastim (SD/01, sustained-duration filgrastim; 100 μg/kg) is as safe and effective as daily filgrastim (5 μg/kg/d) for reducing neutropenia in patients who received four cycles of myelosuppressive chemotherapy. Patients and Methods: Sixty-two centers enrolled 310 patients who received chemotherapy with docetaxel 75 mg/m² and doxorubicin 60 mg/m² on day 1 of each cycle for a maximum of four cycles. Patients were randomized to receive on day 2 either a single subcutaneous injection of pegfilgrastim 100 μg/kg per chemotherapy cycle (154 patients) or daily subcutaneous injections of filgrastim 5 μg/kg/d (156 patients). Absolute neutrophil count (ANC), duration of grade 4 neutropenia, and safety parameters were monitored. Results: One dose of pegfilgrastim per chemotherapy cycle was comparable to daily subcutaneous injections of filgrastim with regard to all efficacy end points, including the duration of severe neutropenia and the depth of ANC nadir in all cycles. Febrile neutropenia across all cycles occurred less often in patients who received pegfilgrastim. The difference in the mean duration of severe neutropenia between the pegfilgrastim and filgrastim treatment groups was less than 1 day. Pegfilgrastim was safe and well tolerated, and it was similar to filgrastim. Adverse event profiles in the pegfilgrastim and filgrastim groups were similar. Conclusion: A single injection of pegfilgrastim 100 μg/kg per cycle was as safe and effective as daily injections of filgrastim 5 μg/kg/d in reducing neutropenia and its complications in patients who received four cycles of doxorubicin 60 mg/m² and docetaxel 75 mg/m².