Kourlaba, G., Dimopoulos, M.A., Pectasides, D., Skarlos, D.V., Gogas, H., Pentheroudakis, G., . . . Maniadakis, N. (2015). Comparison of filgrastim and pegfilgrastim to prevent neutropenia and maintain dose intensity of adjuvant chemotherapy in patients with breast cancer. Supportive Care in Cancer, 23, 2045–2051.
To compare effectiveness of pegfilgrastim given as a prophylactic single-fixed dose versus daily filgrastim for incidence of febrile neutropenia (FN), severe neutropenia, treatment delays, and dose reductions in high-risk breast cancer patients receiving adjuvant dose dense chemotherapy. The secondary aim was to evaluate the impact of both granulocyte–colony-stimulating factors (G-CSFs) on patients’ overall survival (OS).
All patients treated with E-T-CMF received G-CSF in each cycle of chemotherapy. Patients randomized to receive ET-CMF received G-CSF only during intensified phase of CMF treatment; patients randomized to receive E-CMF-DOC or E-CMF-PAC received G-CSF during the intensified phase of epirubicin and CMF treatment. G-CSF was arbitrarily chosen by physicians. Patients received either single fixed dose of pegfilgrastim 6 mg on the next day after chemotherapy completion or daily administration of filgrastim 5 mcg/kg per day on days 2-7 of each cycle (compliance for filgrastim was more than 90% of cycles).
Data endpoints were rates of FN, severe (grade 3 or 4) neutropenia, dose reduction, and treatment delay. FN was defined as body temperature > 38.2 °C and neutrophil count < 0.5 × 109/L. Severe (grade 3 or 4) neutropenia was assessed according to standard NCI criteria. Dose reduction was defined as any reduction greater than 10% of the dose planned based on the protocol assigned, and treatment delay was defined as chemotherapy administration with more than a two-day delay from the planned date.
No difference in rates of febrile neutropenia comparing filgrastim and pegfilgrastim arms existed. A significant increase in rates of severe neutropenia, treatment delays, and dose reduction in patients receiving prophylaxis with filgrastim was reported. More than half of the total episodes of febrile neutropenia occurred during the first four cycles of chemotherapy. No difference in overall survival between the two groups existed.
This retrospective study with matched sampling using data taken from a former prospective study of high-risk patients with breast cancer receiving postoperative dose dense sequential epirubicin, paclitaxel, and CMF matched samples found that those patients receiving pegfilgrastim had reduced incidence and risk for FN, dose delay, and dose reduction compared to filgrastim. No difference was found in reducing rates of neutropenia.
Pegfilgrastim 6 mg 24 hours after chemotherapy is more effective in reducing incidence/risk of FN, dose delay, and dose reduction compared to filgrastim 5 mcg/kg/d on days two through seven in high-risk patients with breast cancer receiving postoperative adjuvant sequential chemotherapy regimens with epirubicin, paclitaxel, or docetaxel and CMF. Prospective randomized, controlled trials are needed to validate these results and to determine specific treatment regimens/population where pegfilgrastim or filgrastim dose/timing may be more effective in preventing FN.