What is the recommended dose of Filgastrim (Granulocyte-Colony Stimulating Factor, G-CSF) for managing post-chemotherapy bone marrow suppression, specifically neutropenia?

From the Guidelines

The recommended dose of filgrastim for managing post-chemotherapy bone marrow suppression, specifically neutropenia, is 5 micrograms per kilogram of body weight once daily, administered as a subcutaneous injection or intravenous infusion, as supported by the most recent and highest quality study 1.

Key Considerations

• Treatment should begin 1 to 3 days after completion of chemotherapy and continue until the absolute neutrophil count (ANC) recovers to a safe level, usually above 1,000-1,500 cells/mm³.
• The medication is typically administered for 7-14 days, depending on the severity of neutropenia and the specific chemotherapy regimen used.
• Patients or caregivers should be instructed on proper subcutaneous injection technique if self-administration is planned.
• Blood counts should be monitored regularly during treatment to assess response.

Mechanism and Side Effects

• Filgrastim works by stimulating the bone marrow to produce neutrophils, thereby reducing the duration and severity of neutropenia and decreasing the risk of serious infections.
• Common side effects include bone pain, which can be managed with analgesics, and potential splenic enlargement in rare cases.
• Dose adjustments may be necessary for patients with renal impairment, as noted in the guidelines 1.

Administration and Monitoring

• The preferred route of filgrastim administration is subcutaneous, as stated in the guidelines 1.
• Regular monitoring of blood counts is essential to assess response to treatment and adjust the dose as needed.
• The dose may be rounded to the nearest vial size by institution-defined weight limits, as noted in the study 1.

From the FDA Drug Label

In Study 1, patients received up to 6 cycles of intravenous chemotherapy including intravenous cyclophosphamide and doxorubicin on day 1; and etoposide on days 1,2, and 3 of 21 day cycles. Patients were randomized to receive filgrastim (n=99) at a dose of 230 mcg/m2 (4 to 8 mcg/kg/day) or placebo (n=111) In Study 4 the initial induction therapy consisted of intravenous daunorubicin days 1,2, and 3; cytosine arabinoside days 1 to 7; and etoposide days 1 to 5 Patients were randomized to receive subcutaneous filgrastim (n=259) at a dose of 5 mcg/kg/day or placebo (n=262) from 24 hours after the last dose of chemotherapy until neutrophil recovery (ANC ≥1,000/mm3 for 3 consecutive days or ≥ 10,000/mm3 for 1 day) or for a maximum of 35 days In Study 6, patients with Hodgkin’s disease received a preparative regimen of intravenous cyclophosphamide, etoposide, and BCNU (“CVP”), and patients with non-Hodgkin’s lymphoma received intravenous BCNU, etoposide, cytosine arabinoside and melphalan (“BEAM”) There were 54 patients randomized 1:1:1 to control, filgrastim 10 mcg/kg/day, and filgrastim 30 mcg/kg/day as a 24-hour continuous infusion starting 24-hours after bone marrow infusion for a maximum of 28 days.

The recommended dose of Filgastrim for managing post-chemotherapy bone marrow suppression, specifically neutropenia, is:

• 230 mcg/m2 (4 to 8 mcg/kg/day) as seen in Study 1 2
• 5 mcg/kg/day as seen in Study 4 2
• 10 mcg/kg/day as seen in Study 6 2 These doses were used in clinical trials and resulted in a reduction in the incidence and duration of neutropenia and febrile neutropenia.

From the Research

Filgastrim Dose for Post-Chemo Bone Marrow Suppression

The recommended dose of Filgastrim (Granulocyte-Colony Stimulating Factor, G-CSF) for managing post-chemotherapy bone marrow suppression, specifically neutropenia, can vary depending on the individual patient and the specific chemotherapy regimen being used.

• The study by 3 found that G-CSF administration was efficacious in chemotherapy-induced neutropenia by decreasing the duration of neutropenia and duration of fever. The patients in this study were given G-CSF until the neutrophil count was >1000/ml for 3 days or a maximum of 7 days.
• Another study by 4 examined the role of pharmacokinetics and delivery protocols in shaping the neutrophil responses to chemotherapy and G-CSF. The study found that the timing of G-CSF administration was crucial for successful reversal of chemotherapy-induced neutropenia.
• A case report by 5 described the administration of cytotoxic systemic therapy with G-CSF in a patient with Shwachman-Diamond syndrome and metastatic breast cancer. The patient received twice-weekly G-CSF and did not experience severe infections.
• A retrospective cohort study by 6 evaluated the effects of prophylactic administration of G-CSF on peripheral leukocyte and neutrophil counts levels after chemotherapy in patients with early-stage breast cancer. The study found that prophylaxis with G-CSF kept the mean values of WBC counts and ANCs within the normal range during chemotherapy.

Key Findings

• G-CSF administration can decrease the duration of neutropenia and duration of fever in patients with chemotherapy-induced neutropenia 3.
• The timing of G-CSF administration is crucial for successful reversal of chemotherapy-induced neutropenia 4.
• G-CSF can be effective in managing chemotherapy-induced neutropenia in patients with underlying bone marrow failure syndromes, such as Shwachman-Diamond syndrome 5.
• Prophylactic administration of G-CSF can stabilize WBC counts and ANCs during chemotherapy in patients with early-stage breast cancer 6.

G-CSF Administration

• The dose and duration of G-CSF administration may vary depending on the individual patient and the specific chemotherapy regimen being used.
• G-CSF can be administered until the neutrophil count is >1000/ml for 3 days or a maximum of 7 days 3.
• Twice-weekly G-CSF administration has been used in some patients, such as those with Shwachman-Diamond syndrome and metastatic breast cancer 5.