DNA synthesis; STAT1

On the other hand, tumors treated with fludarabine at a dose of 40 mg/kg grow less than five times as quickly, taking 25 days to reach approximately 10-fold growth from their initial volume. RPMI8226 tumor growth is shown to be significantly inhibited by fludarabine at a dose of 40 mg/kg. When 40 mg/kg of fludarabine is administered to RPMI8226 tumors on day 10, more apoptotic nuclei are produced. The myeloma xenografts RPMI8226 can be effectively suppressed in SCID mice by fludarabine.[1]

Fludarabine is a nucleoside analogue that has been successfully employed for the treatment of low-grade lymphoid malignancies and, more recently, in nonmyeloablative preparative regimens for stem cell transplantation, due to its strong cytotoxic activity on lymphocytes. In this paper, we show that fludarabine can also induce pro-inflammatory stimulation of monocytic cells, as evaluated by increased expression of ICAM-1 and IL-8 release. To study the mechanisms involved, we employed selective inhibitors of MAPK and NF-kappaB pathways, both of which have been implicated in the modulation of ICAM-1 and IL-8. Our results showed that fludarabine effects were mediated through the activation of ERK and were independent on p38, JNK or NF-kappaB pathways. By Western blotting analysis we corroborated that fludarabine induced a rapid activation of ERK that was sustained for at least 30 min. Moreover, pro-inflammatory activation of monocytic cells by fludarabine was largely attenuated by coadministration of the free radical scavenger N-acetylcysteine suggesting the involvement of reactive oxygen species in fludarabine effects. Finally, we showed that fludarabine induced the activation of the transcription factor AP-1 not only in monocytic cells but also in non-proliferating lymphocytes from chronic lymphocytic leukemia. It is possible that some of fludarabine side effects in vivo may be attributed to cell activation/differentiation rather than induction of apoptosis.[3]

Fludarabine- or control-treated human MM cell lines, RPMI8226 and U266 (5 × 10⁵ cells), that are dexamethasone-sensitive (MM.1S) and -resistant (MM.1R) are fixed with 70% ice-cold ethanol, centrifuged, and suspended in PBS containing 100 μg/mL RNase A. Sampling is done in 25 μg/mL propidium iodide after 30 minutes of incubation at 37 ºC. The FACSCalibur automated system is used to perform flow cytometry. As per the manufacturer's instructions, apoptosis is identified using the Annexin V-FITC apoptosis detection kit. In situ cell death detection kit-assisted flow cytometry is used to analyze cells for the TUNEL (terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end labeling) assay.

Establishment of subcutaneous and disseminated MM xenografts and therapy Severe combined immunodeficient (SCID) mice were housed and maintained in facilities under an institute-approved animal protocol. For the s.c. xenograft MM RPMI 8226 mouse model, 3- to 4-wk-old female mice were inoculated subcutaneously with 10 × 106 RPMI 8226 cells. When tumor volumes approached 100 mm3, the mice were divided into experimental cohorts of six mice each. Injections (i.p.) of fludarabine or PBS (control) were administered each day for 3 d. Tumor volume was calculated by using the formula: 4π/3 × (tumor width/2)2 × (tumor length/2) described as previously .[3]

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Dissolved in PBS; 40 mg/kg; i.p. injection

Severe combined immunodeficient (SCID) mice bearing RPMI 8226 cells

Absorption, Distribution and Excretion
Bioavailability is 55% following oral administration.
117-145 mL/min [patients with B-cell CLL receiving IV administration of a single dose of 40 mg/m^2.
... To compare the pharmacokinetics of sc & iv fludarabine in patients with lupus nephritis. ... Open-label, randomized, crossover trial conducted with a phase I-II trial. ... Government research hospital. ... Five patients with lupus nephritis. ... Fludarabine 30 mg/m2/day was administered either sc or as a 0.5-hr iv infusion for 3 consecutive days. All patients received oral cyclophosphamide 0.5 g/m2 on the first day of each cycle. ... Plasma samples were collected before & 0.5, 1, 1.5, 2, 4, 8, & 24 hrs after the first dose. Urine was collected at 6-hr intervals for 24 hrs. Plasma & urine were analyzed for fluoro-arabinofuranosyladenine (F-ara-A), fludarabine's main metabolite, using high-performance liquid chromatography. Compartmental techniques were used to determine the pharmacokinetics of F-ara-A; a linear two-compartment model best described them. Comparison of the pharmacokinetics between sc & iv admin was done by using a Wilcoxon signed rank test. No significant differences were found between sc & iv admin in median (interquartile range) maximum concns of 0.51 (0.38-0.56) & 0.75 (0.52-0.91) mg/L, respectively, or in fitted area under the concn-time curves from 0-24 hrs of 4.65 (4.17-4.98) & 4.55 (3.5-4.94) mg x hr/L, respectively. Bioavailability of F-ara-A after sc dosing was approx 105% of the bioavailability after iv admin. Differences in renal clearance & % of dose excreted in urine for sc & iv admin were nonsignificant. No injection site reactions were seen with subcutaneous dosing. ... Sc & iv admin of fludarabine appear to have similar pharmacokinetics in patients with lupus nephritis. Sc injection may offer a convenient alternative to iv admin.

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Biological Half-Life
20 hours

Hepatotoxicity
In clinical trials, serum enzymes elevations occurred in only a small proportion of patients treated with fludarabine for leukemia. The role of fludarabine as opposed to other antineoplastics used in antileukemic regimens was not always clear from these studies. Cases of clinically apparent liver injury due to fludarabine have been reported to occur, but few details were available and most patients were receiving other cancer chemotherapeutic agents.
Fludarabine is immunosuppressive and decreases total white blood cell counts and specifically lymphocyte counts and CD8 T cells. As a consequence, fludarabine therapy has been linked to cases of reactivation of chronic hepatitis B, including instances of reverse seroconversion marked by development of HBsAg and active disease in a patient who had resolved hepatitis B before chemotherapy, as shown by presence of anti-HBc without HBsAg. Reactivation typically occurs after 3 to 6 courses of anticancer mediations and most commonly 2 to 4 months after completing chemotherapy. The frequency and severity of reactivation after fludarabine therapy has led to recommendations that patients be screened for HBsAg and anti-HBc before treatment, and give prophylaxis with antiviral therapy using an oral nucleoside with potent activity against HBV, such as lamivudine, tenofovir or entecavir. If prophylaxis is not used, careful monitoring and early institution of antiviral therapy is warranted. Fludarabine has also been associated with development of opportunistic infections including herpes virus and adenovirus infection of the liver.
Likelihood score: E* (Unproven but suspected cause of clinically apparent liver injury).

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Protein Binding
19-29%

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Interactions
Fludarabine may raise the concentration of blood uric acid as part of a tumor lysis syndrome; dosage adjustment of antigout agents /allopurinol, colchicine, probenecid, sulfinpyrazone/ may be necessary to control hyperuricemia and gout; allopurinol may be preferred to prevent or reverse fludarabine-induced hyperuricemia because of risk of uric acid nephropathy with uricosuric antigout agents.
Leukopenic and/or thrombocytopenic effects of fludarabine may be increased with concurrent or recent therapy if these medications /blood dyscrasia causing medications/ cause the same effects; dosage adjustment of fludarabine, if necessary, should be based on blood counts.
Additive bone marrow depression may occur; dosage reduction may be required when two or more bone marrow depressants, including radiation, are used concurrently or consecutively.
Concurrent use with fludarabine is not recommended because of a possible increased risk of fatal pulmonary toxicity. /Pentostatin/
For more Interactions (Complete) data for FLUDARABINE (10 total), please visit the HSDB record page.

[1]. Eur J Haematol . 2007 Dec;79(6):486-93.

[2]. Bioorg Med Chem . 1999 Jun;7(6):1195-200.

[3]. Int Immunopharmacol . 2006 May;6(5):715-23.

[4]. Eur J Cancer . 1996 Sep;32A(10):1766-73.

[5]. Am J Physiol Heart Circ Physiol . 2007 Jun;292(6):H2935-43.

Therapeutic Uses
Fludarabine is indicated for treatment of patients with B-cell chronic lymphocytic leukemia (CLL) who have not responded to or whose disease has progressed during treatment with at least one standard alkylating agent-containing regimen. /Included in US product labeling/
Fludarabine is indicated for treatment of non-Hodgkin's lymphomas. /NOT included in US product labeling/
Fludarabine phosphate is a purine analogue now commonly used in the treatment of low-grade lymphoid malignancies.
A study update to assess long-term survival following fludarabine salvage treatment in previously treated patients with chronic lymphocytic lymphoma (CLL). ... From September 1992 to December 1995, 74 patients with advanced, relapsing B-cell CLL were enrolled in the study. Fludarabine was given for 5 consecutive days at the dose of 25 mg/sq m/day in a 30 min infusion. Treatment was repeated every 28 days for a max of 6 courses. ... Nineteen (26%) patients achieved a complete response (CR) & 20 (27%) patients had a partial response (PR), giving an overall response rate of 53%. The median overall survival was 68 months, & there was a strong negative correlation with the number of previous treatments. The median time to progression was 18 months for patients who achieved a CR & 12 months for those with a PR. ... The results obtained with fludarabine alone in this subset of CLL patients indicate the existence of a conspicuous disease-free survival period. This time window could be used to consolidate the initial response with either biological approaches or high-dose therapeutic strategies such as autologous bone marrow transplantation, with the aim of eventual eradication of the disease.

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Drug Warnings
FLUDARA FOR INJECTION should be administered under the supervision of a qualified physician experienced in the use of antineoplastic therapy. FLUDARA FOR INJECTION can severely suppress bone marrow function. When used at high doses in dose-ranging studies in patients with acute leukemia, FLUDARA FOR INJECTION was associated with severe neurologic effects, including blindness, coma, and death. This severe central nervous system toxicity occurred in 36% of patients treated with doses approximately four times greater (96 mg/sq m/day for 5-7 days) than the recommended dose. Similar severe central nervous system toxicity, including coma, seizures, agitation and confusion, has been reported in patients treated at doses in the range of the dose recommended for chronic lymphocytic leukemia.
Instances of life-threatening and sometimes fatal autoimmune phenomena such as hemolytic anemia, autoimmune thrombocytopenia/thrombocytopenic purpura (ITP), Evan's syndrome, and acquired hemophilia have been reported to occur after one or more cycles of treatment with FLUDARA FOR INJECTION. Patients undergoing treatment with FLUDARA FOR INJECTION should be evaluated and closely monitored for hemolysis.
In a clinical investigation using FLUDARA FOR INJECTION in combination with pentostatin (deoxycoformycin) for the treatment of refractory chronic lymphocytic leukemia (CLL), there was an unacceptably high incidence of fatal pulmonary toxicity. Therefore, the use of FLUDARA FOR INJECTION in combination with pentostatin is not recommended.
The bone marrow depressant effects of fludarabine may result in an increased incidence of microbial infection, delayed healing, & gingival bleeding. Dental work, whenever possible, should be completed prior to initiation of therapy or deferred until blood counts have returned to normal. Patients should be instructed in proper oral hygiene during treatment, including caution in use of regular toothbrushes, dental floss, & toothpicks. Fludarabine also sometimes causes stomatitis associated with considerable discomfort.
For more Drug Warnings (Complete) data for FLUDARABINE (26 total), please visit the HSDB record page.

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Pharmacodynamics
Fludarabine is a chemotherapy drug used in the treatment of chronic lymphocytic leukemia. It acts at DNA polymerase alpha, ribonucleotide reductase and DNA primase, results in the inhibition of DNA synthesis, and destroys the cancer cells.

C10H12FN5O4

285.23

285.087

C, 42.11; H, 4.24; F, 6.66; N, 24.55; O, 22.44

21679-14-1

657237

White to yellow solid powder

2.2±0.1 g/cm3

747.3±70.0 °C at 760 mmHg

265-268ºC

405.8±35.7 °C

0.0±2.6 mmHg at 25°C

1.876

-0.4

4

9

2

20

367

4

FC1=NC(=C2C(=N1)N(C([H])=N2)[C@@]1([H])[C@]([H])([C@@]([H])([C@@]([H])(C([H])([H])O[H])O1)O[H])O[H])N([H])[H]

HBUBKKRHXORPQB-FJFJXFQQSA-N

InChI=1S/C10H12FN5O4/c11-10-14-7(12)4-8(15-10)16(2-13-4)9-6(19)5(18)3(1-17)20-9/h2-3,5-6,9,17-19H,1H2,(H2,12,14,15)/t3-,5-,6+,9-/m1/s1

(2R,3S,4S,5R)-2-(6-amino-2-fluoropurin-9-yl)-5-(hydroxymethyl)oxolane-3,4-diol

2934.99.9001

Powder      -20°C    3 years

                     4°C     2 years

In solvent   -80°C    6 months

                  -20°C    1 month

Room temperature (This product is stable at ambient temperature for a few days during ordinary shipping and time spent in Customs)

Solubility in Formulation 1: ≥ 2.5 mg/mL (8.76 mM) (saturation unknown) in 10% DMSO + 40% PEG300 + 5% Tween80 + 45% Saline (add these co-solvents sequentially from left to right, and one by one), clear solution.
For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 25.0 mg/mL clear DMSO stock solution to 400 μL PEG300 and mix evenly; then add 50 μL Tween-80 to the above solution and mix evenly; then add 450 μL normal saline to adjust the volume to 1 mL.
Preparation of saline: Dissolve 0.9 g of sodium chloride in 100 mL ddH₂ O to obtain a clear solution.

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Solubility in Formulation 2: ≥ 2.5 mg/mL (8.76 mM) (saturation unknown) in 10% DMSO + 90% (20% SBE-β-CD in Saline) (add these co-solvents sequentially from left to right, and one by one), clear solution.
For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 25.0 mg/mL clear DMSO stock solution to 900 μL of 20% SBE-β-CD physiological saline solution and mix evenly.
Preparation of 20% SBE-β-CD in Saline (4°C，1 week): Dissolve 2 g SBE-β-CD in 10 mL saline to obtain a clear solution.

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Solubility in Formulation 3: ≥ 2.5 mg/mL (8.76 mM) (saturation unknown) in 10% DMSO + 90% Corn Oil (add these co-solvents sequentially from left to right, and one by one), clear solution.
For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 25.0 mg/mL clear DMSO stock solution to 900 μL of corn oil and mix evenly.

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Solubility in Formulation 4: 30% propylene glycol, 5% Tween 80, 65% D5W: 30 mg/mL

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 (Please use freshly prepared in vivo formulations for optimal results.)