¹²⁵I-CXCL12-CXCR4 ( IC50 = 44 nM ); ¹²⁵I-CXCL12-CXCR4; HIV-1 (NL4.3 strain) ( IC50 = 9 nM ); HIV-1 ( EC50 = 1-10 nM ); HIV-2 ( EC50 = 1-10 nM )

Plerixafor (2 mg/kg) administration to UUO mice intensifies the infiltration of renal interstitial T cells, leading to elevated levels of pro-inflammatory cytokines, such as IL-6 and IFN-γ, and lowered expression of anti-inflammatory cytokine, IL-10[3]. At eight weeks, the CXCR4 antagonist Plerixafor (AMD3100) significantly reduces both interstitial and perivascular fibrosis[4]. LD50: 16.3 mg/kg for mice; >50 mg/kg for rats; 5.2 mg/kg for mice and rats administered intravenously.

For the competition binding studies against CXCR4, 5 × 105 CCRF-CEM cells and 100 pM 125I-SDF-1α (2200 Ci/mmol) are incubated for three hours at 4 °C in binding buffer (PBS containing 5 mM MgCl2, 1 mM Ca Cl2, 0.25% BSA, pH 7.4) in Milipore DuraporeTM filter plates. After washing with cold 50 mM HEPES and 0.5 M NaCl pH 7.4, unbound 125I-SDF-1α is eliminated. On membranes from CHO-S cells expressing recombinant BLT1, the competition binding assay is carried out. Mechanical cell lysis, high-speed centrifugation, resuspension in 50 mm HEPES buffer containing 5 mM MgCl22, and flash freezing are the steps involved in the preparation of the membranes. The assay mixture comprising 50 mM Tris, pH 7.4, 10 mM MgCl2, 10 mM CaCl2, 4 nM LTB4 combined with 1 nM 3H-LTB4 (195.0 Ci/mmol) and 8 μg membrane is incubated with Plerixafor for one hour at room temperature. Filtration is used to separate the unbound 3H-LTB4 on Millipore Type GF-C filter plates.

U87MG cells are treated with CXCL12, Plerixafor, or peptide R, as mentioned in the previous "Treatments" section, after being seeded in 96-well plates at a density of 6x103 cells in 200 μL/well. During the last two hours of treatment, MTT (5 μg/mL) is added at 24, 48, and 72 hours. Following the removal of the cell medium, 100 μL of DMSO is added, and an LT-4000MS Microplate Reader is used to measure the optical densities at 595 nm. Triplicate measurements are taken from three separate experiments[2].

Absorption
Plerixafor follows a two-compartment pharmacokinetic profile with first-order absorption and exhibits linear kinetics between 0.04 mg/kg and 0.24 mg/kg. The pharmacokinetic profile of plerixafor in healthy subjects was similar to the one observed in patients with non-Hodgkin’s lymphoma (NHL) and multiple myeloma (MM) who received plerixafor in combination with granulocyte-colony stimulating factor (G-CSF). In addition, the clearance of plerixafor has a significant relationship with creatinine clearance (CLCR). The population pharmacokinetic analysis showed that, with increasing body weight, a mg/kg-based dosage leads to a higher plerixafor exposure (AUC0-24h). However, NHL patients (<70 kg) given a fixed dose of 20 mg of plerixafor had an AUC0-10h 1.43-fold higher than the one detected in patients given 0.24 mg/kg of plerixafor. Therefore, a body weight of 83 kg was selected as an appropriate cut-off point to transition patients from fixed to weight-based dosing. Peak concentrations are reached in approximately 30-60 minutes (tmax) following subcutaneous injection. In patients given 0.24 mg/kg of plerixafor subcutaneously after receiving 4-days of G-CSF pre-treatment, the Cmax and AUC0-24 were 887 ng/ml and 4337 ng·hr/ml, respectively.

Route of Elimination
Plerixafor is mainly eliminated through urine. In healthy volunteers with normal renal function given 0.24 mg/kg of plerixafor, approximately 70% of the parent drug is excreted in urine in the first 24 hours. An _in vitro_ study with MDCKII and MDCKII-MDR1 cell models found that plerixafor is not a substrate or inhibitor of P-glycoprotein.

Volume of Distribution
Plerixafor has an apparent volume of distribution of 0.3 L/kg.

Clearance
Plerixafor has a total plasma clearance of 4.38 L/h, and a renal clearance of 3.15 L/h.

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Metabolism / Metabolites
Plerixafor is not metabolized by the liver and is not a metabolism-dependent inhibitor of major cytochrome P450 enzymes, including 1A2, 2C9, 2C19, 2D6 and 3A4. In addition, it does not induce cytochrome P450 1A2, 2B6, or 3A4 enzymes. Plerixafor is metabolically stable, and _in vivo_ studies in rats and dogs showed that the non-parent radiolabelled components in plasma and urine were Cu2+ complexes with plerixafor. This is consistent with the presence of two cyclam rings in plerixafor, which may act as potential chelating sites.

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Biological Half-Life
Plerixafor has a distribution half-life of 0.3 hours and a terminal population half-life of 5.3 hours in patients with normal renal function. In studies with healthy subjects and patients, the terminal half-life in plasma ranges between 3 and 5 hours. In patients with non-Hodgkin lymphoma, the terminal half-life of plerixafor is 4.4 hours, and in patients with multiple myeloma, the terminal half-life is 5.6 hours.

Hepatotoxicity
Plerixafor has not been linked to instances of significant serum enzyme elevations during therapy nor to cases of clinically apparent liver injury. In multiple large prelicensure as well as postmarketing controlled trials, neither ALT elevations or acute liver injury were mentioned as adverse events or reasons for drop out, early discontinuation of therapy or dose modification. There have been no published reports of liver injury attributed to plerixafor, and it has been used as a possible means of treatment in animal models of acute liver failure. Thus, clinically apparent liver injury due to plerixafor must be rare, if it exists at all. Likelihood score: E (unlikely cause of clinically apparent liver injury).

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Protein Binding
The human plasma protein binding of plerixafor is up to 58%.

[1]. Elucidation of CXCR7-mediated signaling events and inhibition of CXCR4-mediated tumor cell transendothelial migration by CXCR7 ligands. J Immunol. 2009 Sep 1;183(5):3204-11.

[2]. Targeting CXCR4 by a selective peptide antagonist modulates tumor microenvironment and microglia reactivity in a human glioblastoma model. J Exp Clin Cancer Res. 2016 Mar 25;35:55.

[3]. Continuous AMD3100 Treatment Worsens Renal Fibrosis through Regulation of Bone Marrow Derived Pro-Angiogenic Cells Homing and T-Cell-Related Inflammation. PLoS One. 2016 Feb 22;11(2):e0149926.

[4]. CXCR4 Antagonism Attenuates the Development of Diabetic Cardiac Fibrosis. PLoS One. 2015 Jul 27;10(7):e0133616.

[5]. HIV co-receptor inhibitors as novel class of anti-HIV drugs. Antiviral Res. 2006 Sep;71(2-3):216-26.

See also: Plerixafor (annotation moved to).

C28H54N8.8HCL

794.47

826.281

C, 42.33; H, 7.87; Cl, 35.70; N, 14.10

155148-31-5

Plerixafor; 110078-46-1

65014

White solid powder

0.962g/cm3

657.5ºC at 760mmHg

361.8ºC

2.85E-33mmHg at 25°C

8.68

14

8

4

44

456

0

[H]Cl.[H]Cl.[H]Cl.[H]Cl.[H]Cl.[H]Cl.[H]Cl.[H]Cl.N1(CCCNCCNCCCNCC1)CC2=CC=C(C=C2)CN3CCCNCCNCCCNCC3

UEUPDYPUTTUXLJ-UHFFFAOYSA-N

InChI=1S/C28H54N8.8ClH/c1-9-29-15-17-31-13-3-21-35(23-19-33-11-1)25-27-5-7-28(8-6-27)26-36-22-4-14-32-18-16-30-10-2-12-34-20-24-36;;;;;;;;/h5-8,29-34H,1-4,9-26H2;8*1H

1-[[4-(1,4,8,11-tetrazacyclotetradec-1-ylmethyl)phenyl]methyl]-1,4,8,11-tetrazacyclotetradecane;octahydrochloride

2934.99.9001

Powder      -20°C    3 years

                     4°C     2 years

In solvent   -80°C    6 months

                  -20°C    1 month

Note: Please store this product in a sealed and protected environment, avoid exposure to moisture.

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: 120 mg/mL (151.04 mM) in PBS (add these co-solvents sequentially from left to right, and one by one), clear solution; with sonication.

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Solubility in Formulation 2: Saline: 30 mg/mL

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