Granulocyte colony-stimulating factor (G-CSF)

G-CSF (e.g., Filgrastim, Pegfilgrastim)

• Class: Myeloid growth factor
• Mechanism: Stimulates proliferation and differentiation of neutrophil precursors → reduces duration/severity of neutropenia
• Common Uses:
  • Prophylaxis or treatment of chemotherapy-induced neutropenia
  • Support in high-risk regimens or febrile neutropenia
• Key Toxicities:
  • Bone pain (very common)
  • Splenic rupture (rare but serious)
  • Injection site reactions, leukocytosis
• Administration:
  • Filgrastim: Daily SC/IV
  • Pegfilgrastim: Once per cycle (SC, long-acting)
• Important Caution with Bleomycin:
  • Avoid concurrent use with bleomycin-containing regimens (e.g., BEP) due to increased risk of pulmonary toxicity
    • Mechanism unclear, but thought to synergistically worsen lung injury