A pilot study on intermittent every other days of 5-dose Filgrastim compared with single Pegfilgrastim in breast Cancer patients receiving adjuvant Docetaxel, doxorubicin, and cyclophosphamide (TAC) chemotherapy

Aim To compare the efficacy and safety of intermittent every other days 5-dose filgrastim with single pegfilgrastim in patients with breast cancer receiving adjuvant docetaxel, doxorubicin, and cyclophosphamide (TAC) chemotherapy. Methods In this pilot study, Korean patients who had undergone complete resection for breast cancer and scheduled for adjuvant TAC chemotherapy were enrolled. Patients were randomized to receive either intermittent 5 doses of filgrastim (5 mcg/kg/day) or once-a-cycle pegfilgrastim (6 mg) as primary prophylaxis during the first three cycles of the TAC chemotherapy. Absolute neutrophil count (ANC) was analyzed as well. Results A total of 22 patients were randomly and equally divided into filgrastim or pegfilgrastim arms. Febrile neutropenia (FN) occurred in 1 patient in the pegfilgrastim arm (1 of 33 cycles) and none in the filgrastim arm. G3 neutropenia occurred in 1 patient (1 of 33 cycles) in the filgrastim arm and 2 patients (4 of 33 cycles) in the pegfilgrastim arm (P = 0.476). G4 neutropenia occurred in 11 patients (28 of 33 cycles) in the filgrastim arm and 9 patients (18 of 33 cycles) in the pegfilgrastim arm (P = 0.476). Except for on day 9 in cycle 3, there was no significant difference between the two groups in terms of ANC. Conclusion We observed no significant differences between the two methods of prophylaxis in terms of FN and G3/4 neutropenia incidence in patients receiving adjuvant TAC chemotherapy. Intermittent every other days 5-dose filgrastim may be available alternative to pegfilgrastim.