From the Guidelines
Filspari, also known as filgrastim, is indicated for the prevention of febrile neutropenia in patients receiving myelotoxic chemotherapy, and its use should be started 1 to 3 days after administration of chemotherapy. The recommended dose of filgrastim is 5 μg/kg per day, which should be continued until the absolute neutrophil count (ANC) reaches 2 to 3 x 10^9/L 1.
Key Points
- Filgrastim should be administered subcutaneously, and the dose may be rounded to the nearest vial size by institution-defined weight limits 1.
- Pegfilgrastim, a pegylated form of filgrastim, can also be used for the prevention of febrile neutropenia, with a recommended dose of 6 mg per cycle of treatment, administered 1 to 3 days after completion of chemotherapy 1.
- Sargramostim, a granulocyte-macrophage colony-stimulating factor (GM-CSF), can be used in certain clinical settings, such as after induction chemotherapy in older adult patients with acute myeloid leukemia (AML) 1.
Administration and Monitoring
- The subcutaneous route is preferred for all myeloid growth factors, including filgrastim, pegfilgrastim, and sargramostim 1.
- Regular monitoring of ANC, blood pressure, and liver enzymes is necessary during treatment with myeloid growth factors 1.
- Prophylactic antibiotics are not routinely recommended for patients receiving myeloid growth factors, unless otherwise indicated by clinical guidelines or institutional policies 1.
From the FDA Drug Label
ZARXIO is a man-made form of granulocyte colony-stimulating factor (G‑CSF). The efficacy of filgrastim was studied in a randomized, blinded, placebo-controlled study in a non-human primate model of radiation injury Filgrastim significantly (at 0. 023 level of significance) reduced 60-day mortality in the irradiated non-human primates: 21% mortality (5/24) in the filgrastim group compared to 59% mortality (13/22) in the control group
The indications for Filspari (filgrastim) include:
- Severe Chronic Neutropenia: to reduce the incidence and duration of sequelae of neutropenia (fever, infections, oropharyngeal ulcers) in symptomatic adult and pediatric patients with congenital neutropenia, cyclic neutropenia, or idiopathic neutropenia.
- Patients Acutely Exposed to Myelosuppressive Doses of Radiation (Hematopoietic Syndrome of Acute Radiation Syndrome): to increase survival in patients acutely exposed to myelosuppressive doses of radiation. 2, 2, 2
From the Research
Filspari Indication
- Filspari, also known as filgrastim, is used to prevent neutropenia and maintain dose intensity of adjuvant chemotherapy in patients with cancer 3, 4, 5, 6, 7
- The medication is used to assist recovery in patients with low white blood cell counts, which is a common side effect of chemotherapy 4
- Filgrastim, pegfilgrastim, and sargramostim are colony-stimulating factors used as prophylaxis against hospitalization for neutropenic complications in patients with cancer receiving chemotherapy 3, 5, 6
Comparison of Filgrastim, Pegfilgrastim, and Sargramostim
- Studies have compared the effectiveness of filgrastim, pegfilgrastim, and sargramostim in preventing hospitalization for febrile neutropenia and neutropenic complications 3, 5, 6
- Pegfilgrastim has been associated with a lower risk of neutropenia-related and all-cause hospitalizations compared to filgrastim and sargramostim 3, 5
- However, one study found that sargramostim was associated with a reduced risk of infection-related hospitalization and lower associated costs compared to filgrastim or pegfilgrastim 6
Clinical Considerations
- The choice of colony-stimulating factor may depend on various factors, including the type of cancer, chemotherapy regimen, and patient characteristics 4, 7
- Prophylactic dosing of filgrastim and pegfilgrastim can be cost-effective, especially with increasing hospitalization costs 4
- Clinical outcomes can be improved through a reduction in length of hospital stays and the need for IV antibiotic administration 4