GRANIX
Clinical safety rating: caution
Comprehensive clinical and safety monograph for GRANIX (GRANIX).
Granix (tbo-filgrastim) is a recombinant human granulocyte colony-stimulating factor (G-CSF) analog that binds to G-CSF receptors on hematopoietic progenitor cells, stimulating proliferation, differentiation, and release of neutrophils from the bone marrow.
| Metabolism | Primarily cleared by renal excretion and neutrophil-mediated degradation; not extensively metabolized by hepatic enzymes. |
| Excretion | Primarily renal excretion; neutrophil-mediated clearance. <1% unchanged in urine. |
| Half-life | Terminal half-life approximately 3.5 hours (range 1.8–5.4 h) in healthy subjects; clearance increases with neutrophil recovery due to G-CSF receptor-mediated uptake. |
| Protein binding | Approximately 60–70% bound to plasma proteins, primarily albumin. |
| Volume of Distribution | Volume of distribution (Vd) approximately 0.5–0.6 L/kg, indicating distribution limited primarily to plasma and extracellular fluid. |
| Bioavailability | Subcutaneous: Approximately 80% (range 60–100%) relative to intravenous administration. |
| Onset of Action | Subcutaneous: Increase in absolute neutrophil count (ANC) observed within 24 hours; peak ANC achieved in 3–5 days after daily dosing. |
| Duration of Action | Duration of ANC elevation persists for the duration of daily administration; once discontinued, ANC returns to baseline within 1–2 days. |
5 μg/kg subcutaneously once daily for up to 7 days, or 5 μg/kg subcutaneously once daily for up to 14 days for stem cell mobilization.
| Dosage form | INJECTABLE |
| Renal impairment | No dose adjustment required for any degree of renal impairment. |
| Liver impairment | No dose adjustment required for mild to moderate hepatic impairment (Child-Pugh A or B). Not studied in severe hepatic impairment (Child-Pugh C). |
| Pediatric use | Safety and efficacy in pediatric patients (<18 years) have not been established. |
| Geriatric use | No specific dose adjustment required; contraindicated in patients with sickle cell disease (crisis), which may be more relevant in older adults with sickle cell trait. |
| 1st trimester | Consult provider |
| 2nd trimester | Consult provider |
| 3rd trimester | Consult provider |
Clinical note
Comprehensive clinical and safety monograph for GRANIX (GRANIX).
| Breastfeeding | Unknown if filgrastim is excreted in human milk. M/P ratio not available. Caution recommended; benefit of breastfeeding should be weighed against potential risk to infant. |
| Teratogenic Risk | Pregnancy Category C. No adequate studies in pregnant women. In animal reproduction studies, filgrastim (the active ingredient) did not cause teratogenic effects at doses up to 575 mcg/kg/day in rats and 125 mcg/kg/day in rabbits, but there was an increase in fetal resorption and post-implantation loss at maternally toxic doses. Risk cannot be ruled out; use only if potential benefit justifies potential risk to fetus. |
■ FDA Black Box Warning
Splenic rupture (including fatal cases); Acute respiratory distress syndrome (ARDS); Allergic reactions (including anaphylaxis); Increased risk of myelodysplastic syndrome (MDS) and acute myeloid leukemia (AML) in breast cancer or lung cancer patients receiving chemotherapy and/or radiotherapy.
| Serious Effects |
["History of serious allergic reactions to tbo-filgrastim or filgrastim products"]
| Precautions | ["Splenic rupture","Acute respiratory distress syndrome (ARDS)","Allergic reactions","Sickle cell disease crisis","Glomerulonephritis","Leukocytosis","Capillary leak syndrome","Myelodysplastic syndrome and acute myeloid leukemia risk in some indications"] |
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| Fetal Monitoring | Monitor complete blood count (CBC) with differential, particularly absolute neutrophil count (ANC). Assess for splenic rupture (abdominal pain, left upper quadrant pain, or shoulder tip pain). Monitor respiratory status for potential acute respiratory distress syndrome (ARDS). |
| Fertility Effects | No human data on fertility effects. Animal studies have not shown impaired fertility at clinically relevant doses. |