Description_x000D_ General description_x000D_ Fludarabine is a purine analog included in the category of DNA-damaging drugs with well-known efficacy in B-cell chronic lymphocytic leukemia (B-CLL)._x000D_ Biochem/physiol Actions_x000D_ Fludarabine represses DNA replication and suppresses the nucleotide metabolism by inhibiting the enzyme ribonucleotide reductase.