fludarabine + cytarabine + filgrastim

The combination of fludarabine, cytarabine, and filgrastim—commonly referred to as the FLAG regimen—is an intensive chemotherapy protocol primarily used for the treatment of acute myeloid leukemia (AML) and sometimes myelodysplastic syndromes (MDS)[1][2][3]. Fludarabine is a purine analog that inhibits DNA synthesis by interfering with DNA polymerase and ribonucleotide reductase. Cytarabine is a pyrimidine analog that inhibits DNA synthesis by incorporating into DNA and inhibiting DNA polymerase. Filgrastim is a recombinant granulocyte colony-stimulating factor (G-CSF) that stimulates neutrophil production to reduce the risk of infection during periods of neutropenia caused by chemotherapy[8]. The rationale for this combination is that fludarabine increases intracellular levels of ara-CTP, the active metabolite of cytarabine, thereby enhancing its efficacy; G-CSF accelerates neutrophil recovery post-treatment and may sensitize leukemic cells to chemotherapy[1][5][6].

Other names

FLAG regimen