Leukocytosis Following Pegfilgrastim Administration

Mechanism and Expected Effects

• Pegfilgrastim is a long-acting form of granulocyte colony-stimulating factor (G-CSF) developed to reduce the inconvenience of daily G-CSF injections, stimulating neutrophil production after myelosuppressive chemotherapy, which inherently leads to increased white blood cell counts 1, 2

Clinical Evidence of Leukocytosis

• The American Society of Clinical Oncology guidelines expressed concern about potential leukocytosis following pegfilgrastim administration, with a focus on the potential risks and benefits of this treatment 3, 4

Clinical Implications

• Pegfilgrastim has been shown to be effective in reducing the risk of febrile neutropenia compared to filgrastim, with a reported risk reduction of 11% vs 19% 1, 5
• The standard adult dose of pegfilgrastim is 6 mg administered once 1-3 days after chemotherapy, as recommended by clinical guidelines 6, 7