Fludarabine, 氟达拉滨

Fludarabine is an equilibrative nucleoside analog that inhibits DNA synthesis by blocking the enzyme ribonucleotide reductase. It is a potent inducer of apoptosis and has been used in autologous stem-cell transplantation for leukemia. Fludarabine has significant up-regulation of Bcl-2 protein levels, which may be responsible for its potent induction of apoptosis. Fludarabine also has a number of drug interactions, including the ability to inhibit the metabolism of other drugs through inhibition of cytochrome P450 enzymes. Fludarabine is not active against opportunistic fungal infections.

Fludarabine is used to treat chronic lymphocytic (CLL) and in immunosuppressive regimens to prepare for hematopoietic stem cell transplantation. Fludarabine is associated with a low rate of transient serum enzyme levels during therapy. It has rarely been implicated with clinically apparent acute liver injury and jaundice. Fludarabine's immunosuppressive properties are potent and associated with many cases of reactivating hepatitis B.

Pharmacology of Fludarabine

Fludarabine is an antiviral fluorinated nucleotide analog to vidarabine (ara–A). It has antineoplastic activities.

Fludarabine is administered parenterally as an intracellular phosphate salt. After rapidly dephosphorylated into 2-fluoroara-A, Fludarabine's phosphate is phosphorylated intracellularly using deoxycytidine kinase. This metabolite could inhibit DNA polymerase A, primate, and ribonucleotide oxidase. In this way, it can interrupt DNA synthesis and inhibit tumor cell growth.

Biological effects of Fludarabine

Fludarabine inhibits DNA synthesis. The drug is converted into active metabolite F ara-A.

This inhibits Ribonucleotide Reductase as well as competitively inhibiting DNA polymerase. It also prevents DNA-ligase I (DNA ligase 1) from joining DNA. It induces apoptosis.

Purine nucleosides have been resistant to deamination to treat many leukemias due to their antitumor activities inhibiting DNA synthesis. Fludarabine is an adenosine deaminase-resistant analog of 9-b-D-arabinofuranosyladenine (ara-A) that disrupts ribonucleotide reductase and DNA polymerase in blood cells. It is antiproliferative (IC50 = 1.54 mM from RPMI-8226) and triggers apoptosis via increasing Bax and decreasing Bid.

Uses of Fludarabine

Fludarabine can be used to treat hematological malignancies. Fludarabine injection falls under the umbrella of antimetabolites. It treats a white blood cell cancer called B-cell chronic Lymphocytic Leukemia (CLL). It is used to treat patients suffering from CLL who have been unsuccessfully treated with an alkylating drug (e.g., bendamustine).

Fludarabine works well in many animal tumor systems, including CD8F mammary cancer, CD210 leukemia, CD8F leukemia, CD8F tumor xenograft, and CD8F CD8F leukemia.

Title: Fludarabine

CAS Registry Number: 21679-14-1

CAS Name: 9-b-D-Arabinofuranosyl-2-fluoro-9H-purin-6-amine

Additional Names: 9-b-D-arabinofuranosyl-2-fluoroadenine; 2-fluorovidarabine; 2-fluoro-9-b-D-arabinofuranosyladenine; 2-F-araA

Manufacturers' Codes: NSC-118218; NSC-118218-H

Molecular Formula: C10H12FN5O4

Molecular Weight: 285.23

Percent Composition: C 42.11%, H 4.24%, F 6.66%, N 24.55%, O 22.44%

Literature References: Adenosine deaminase-resistant purine nucleoside antimetabolite. Prepn and in vitro cytotoxicity: J. A. Montgomery, K. Hewson, J. Med. Chem. 12, 498 (1969). Improved prepn: J. A. Montgomery et al., J. Heterocycl. Chem. 16, 157 (1979); J. A. Montgomery, US 4210745 (1980 to U.S. Dept. Health, Education and Welfare). Inhibition of DNA synthesis and in vivo antileukemic activity: R. W. Brockman et al., Biochem. Pharmacol. 26, 2193 (1977). Metabolized to 5¢-monophosphate: R. W. Brockman et al., Cancer Res. 40, 3610 (1980). HPLC determn in human leukemia cells: V. Gandhi et al., J. Chromatogr. 413, 293 (1987). Prepn of 5¢-monophosphate: J. A. Montgomery, A. T. Shortnacy, US 4357324 (1982 to U.S. Dept. of Health and Human Services). Pharmacokinetics in humans: M. R. Hersh et al., Cancer Chemother. Pharmacol. 17, 277 (1986). Evaluation of therapeutic efficacy and CNS toxicity in acute refractory leukemia: R. P. Warrell, Jr., E. Berman, J. Clin. Oncol. 4, 74 (1986); H. G. Chun et al., Cancer Treat. Rep. 70, 1225 (1986). Series of articles on pharmacology and therapeutic use: Semin. Oncol. 17, Suppl. 8, 1-78 (1990).

Properties: Crystals from ethanol + water, mp 260°. [a]D25 +17 ±2.5° (c = 0.1 in ethanol). uv max (pH 1, pH 7, pH 13): 262, 261, 262 nm (e ´ 10-3 13.2, 14.8, 15.0). Sparingly sol in water, organic solvents.

Melting point: mp 260°

Optical Rotation: [a]D25 +17 ±2.5° (c = 0.1 in ethanol)

Absorption maximum: uv max (pH 1, pH 7, pH 13): 262, 261, 262 nm (e ´ 10-3 13.2, 14.8, 15.0)

Derivative Type: 5'-Monophosphate

CAS Registry Number: 75607-67-9

Additional Names: 2-F-ara-AMP

Manufacturers' Codes: NSC-328002; NSC-312887

Trademarks: Fludara (Schering AG)

Molecular Formula: C10H13FN5O7P

Molecular Weight: 365.21

Percent Composition: C 32.89%, H 3.59%, F 5.20%, N 19.18%, O 30.67%, P 8.48%

Properties: Sol in water.

Therap-Cat: Phosphate as antineoplastic.

Keywords: Antineoplastic; Antimetabolites; Purine Analogs.