CXCR4 (IC50 = 1 nM)
Motixafortide targets the C-X-C motif chemokine receptor 4 (CXCR4). It blocks the binding of its ligand, stromal-derived factor-1α (SDF-1α)/C-X-C Motif Chemokine Ligand 12 (CXCL12). Motixafortide specifically triggers CXCR4-dependent cell death in leukemia and multiple myeloma cells. It stimulates apoptotic cell death in leukemia and multiple myeloma cells. Motixafortide exhibits selective toxicity against AML and MM cells.

BKT140, also known as motixafortide, demonstrates specific toxicity to AmL and MM cells. Treatment with motixafortide (BKT140) prevents ARH77 MM cells from proliferating and surviving in response to IL-6. In leukemia and MM cells, motixafortide (BKT140) exclusively causes CXCR4-dependent cell death. In leukemia and MM cells, motixafortide (BKT140) induces apoptotic cell death [2].
In vitro, motixafortide exhibits selective toxicity against AML and MM cells by specifically inducing CXCR4-dependent and apoptotic cell death in these leukemia and multiple myeloma cell types. It is a novel CXCR4 antagonist with an IC50 value of approximately 1 nM. Motixafortide (BKT140) specifically triggers CXCR4-dependent cell death in leukemia and MM cells. It stimulates apoptotic cell death in leukemia and MM cells.

In a dose-dependent manner, subcutaneous injection of motixafortide (BKT140) effectively inhibits the growth of human acute myeloid leukemia and multiple myeloma xenografts. Motixafortide (BKT140)-treated animals showed increased necrotic regions, decreased tumor weight and size, and higher apoptosis scores [2].
In vivo, motixafortide has been evaluated in animal models of hematological malignancies and stem cell mobilization. Treatment with motixafortide in animals leads to increased necrotic areas and elevated apoptotic scores. The compound is indicated for use in combination with filgrastim to mobilize hematopoietic stem cells to the peripheral blood for collection and subsequent autologous transplantation in patients with multiple myeloma.

In vitro receptor binding assays for motixafortide involve measuring its binding affinity to CXCR4. The receptor is incubated with a radiolabeled ligand and varying concentrations of motixafortide. The displacement of the radiolabeled ligand is measured, and the IC50 or Ki value is calculated. The compound's functional activity is assessed using calcium flux assays or chemotaxis assays in cells expressing CXCR4.

Hematopoietic cancer cells were exposed to varying concentrations of either Motixafortide (BKT140) or AMD3100 for 24 hours. Prior to use, the Motixafortide was acidified with 1M HCl to a pH of 2.7–3.0 for 30 minutes at room temperature and then neutralized to pH 7 with concentrated NaOH. The compound was subsequently digested with Proteinase K (final concentration 100 µg/mL) at 37°C for one hour, followed by heat inactivation at 65°C for 30 minutes. Following the 24‑hour incubation with the compounds, cell viability was assessed by propidium iodide (PI) staining, with the percentage of viable PI‑negative cells being quantified[2].
In vitro cell-based assays for motixafortide evaluate its effects on leukemia and multiple myeloma cells. Cells are cultured in appropriate media and treated with serial dilutions of motixafortide. Cell viability is assessed using MTT or CellTiter-Glo assays. Apoptosis is assessed by measuring caspase activity or by Annexin V staining. The compound's effects on CXCR4 signaling are assessed by measuring calcium flux or ERK phosphorylation.

The study employed severe combined immunodeficient (SCID)/beige mice (strain C.B-17/IcrHsd-SCID-bg). NB4 cells, resuspended in phosphate-buffered saline (PBS), were injected subcutaneously into the mouse flanks (200 µL per injection containing 5 × 10⁶ cells). Tumor growth was monitored daily. Once tumors reached a size of 0.04 cm² (calculated as width × length), mice were randomized into either a drug-treated group or a PBS-treated control group, with 10 mice per group. BKT140 was administered via subcutaneous injection at a daily dose of 200 µg per mouse for a duration of 5 days[2].
In vivo, motixafortide is evaluated in animal models of multiple myeloma and stem cell mobilization. Immunocompromised mice bearing multiple myeloma xenografts are treated with motixafortide, and tumor growth is monitored. The compound's ability to mobilize hematopoietic stem cells is assessed by measuring the number of CD34+ cells in the peripheral blood. Pharmacokinetic studies are conducted to determine the compound's half-life, clearance, and tissue distribution.

Absorption, Distribution and Excretion
Following subcutaneous injection, the Tmax of motixafortide ranges from 0.25 to 1.17 hours. In animal studies, approximately 80% of the radioactive material was excreted in the urine after administration of radiolabeled motixafortide. No parent drug was detected in the urine, and no single metabolite exceeded 30% of the total clearance. In typical patients, the estimated volume distributed to the central compartment is 27 liters. The apparent total clearance of motixafortide in typical patients is 46.5 liters/hour. Metabolism/Metabolites Motixafortide is broken down into smaller peptides and amino acids through a nonspecific catabolic process. Biological Half-Life The effective half-life of motixafortide in human plasma is approximately 2 hours.
Motixafortide (BL-8040, BKT140) is a 14-residue biostable synthetic cyclic peptide that functions as a high-affinity antagonist of CXCR4. It has a molecular formula of C₉₇H₁₄₄FN₃₃O₁₉S₂ and a molecular weight of 2159.52 g/mol. Motixafortide is indicated for use in combination with filgrastim to mobilize hematopoietic stem cells. It is under clinical investigation for the treatment of hematological malignancies, solid tumors, and stem cell mobilization.

Protein Binding
Motisafortide binds extensively to human plasma proteins (>99%), but the specific proteins it binds to are not yet known.
The toxicity of motixafortide has been evaluated in preclinical and clinical studies. The compound has shown a favorable safety profile at therapeutic doses. Common adverse effects include injection site reactions, nausea, and fatigue. The compound's safety in patients with multiple myeloma has been established in clinical trials. Motixafortide is approved for use in combination with filgrastim for stem cell mobilization.

[1]. The high-affinity CXCR4 antagonist BKT140 is safe and induces a robust mobilization of human CD34+ cellsin patients with multiple myeloma. Clin Cancer Res. 2014 Jan 15;20(2):469-79.

[2]. CXCR4 antagonist 4F-benzoyl-TN14003 inhibits leukemia and multiple myeloma tumor growth. Exp Hematol. 2011 Mar;39(3):282-92.

Motixafotide is a heterocyclic peptide with antitumor activity. It is a CXC chemokine receptor 4 (CXCR4) antagonist with an IC50 of 0.8 nM and is currently undergoing clinical trials for the treatment of hematologic malignancies, solid tumors, and stem cell mobilization. In 2019, the U.S. Food and Drug Administration (FDA) granted it orphan drug designation for the treatment of pancreatic cancer. It exhibits apoptosis-inducing, antitumor, and CXC chemokine receptor 4 antagonistic effects. Motixafotide is a cyclic peptide hematopoietic stem cell mobilizing agent used to improve stem cell collection before autologous transplantation. Hematopoietic stem cell transplantation (HSCT) is a common treatment for hematologic malignancies—high-dose chemotherapy regimens destroy cancerous blood cells, which are then replaced by the infusion of the patient's own stem cells (i.e., autologous transplantation). The mechanism of action of motixafotide is similar to that of the previously approved plexafotide; it is a CXC motif chemokine receptor 4 (CXCR4) inhibitor, a protein that helps anchor stem cells to the bone marrow matrix. When used in combination with filgrastim, another drug used to assist in stem cell collection, motixafortide can provide a sufficient number of stem cells in approximately 92% of patients after two hematopoietic stem cell ablation procedures, compared to approximately 26% in patients receiving filgrastim alone. In September 2023, the U.S. Food and Drug Administration (FDA) approved motixafortide in combination with filgrastim for stem cell mobilization prior to autologous stem cell transplantation in patients with multiple myeloma. Motixafortide has also been studied in combination with pembrolizumab for the treatment of pancreatic cancer. Motixafortide is an orally bioavailable CXC chemokine receptor 4 (CXCR4) inhibitor with potential antitumor activity. The CXCR4 antagonist BL-8040 selectively binds to the chemokine receptor CXCR4, preventing stromal cell-derived factor 1 (SDF-1 or CXCL12) from binding to the CXCR4 receptor, thereby inhibiting receptor activation, which may lead to reduced tumor cell proliferation and migration. Furthermore, inhibition of CXCR4 may induce the mobilization of hematopoietic cells from the bone marrow into the bloodstream. The G protein-coupled receptor CXCR4 plays a crucial role in chemotaxis and angiogenesis and is upregulated in various tumor cell types; the SDF-1/CXCR4 interaction can induce hematopoietic cell retention in the bone marrow. Drug Indications Motixafotide is indicated for use in combination with [filgrastim] to mobilize hematopoietic stem cells into the peripheral blood for collection and subsequent autologous transplantation in the treatment of patients with multiple myeloma. Mechanism of Action Motixafotide is an inhibitor of CXC motif chemokine receptor 4 (CXCR4), blocking the binding of its ligand stromal cell-derived factor-1α (SDF-1α)/CXC motif chemokine ligand 12 (CXCL12). Both CXCR4 and SDF-1α are involved in the transport of hematopoietic stem cells to the bone marrow cavity, with CXCR4 facilitating the anchoring of stem cells to the bone marrow matrix (through induction by SDF-1α or other adhesion molecules). Therefore, inhibition of CXCR4 increases the number of circulating hematopoietic stem cells and progenitor cells, thereby promoting their entry into peripheral circulation and facilitating autologous transplantation.
Pharmacodynamics
In vitro studies showed that motixafotide has an IC50 of 0.42–4.5 nM for CXCR4, and its binding affinity and dissociation rate maintain receptor occupancy for more than 72 hours. In healthy volunteers receiving motixafotide monotherapy, CD34+ cell counts increased over time, peaking at 16 hours post-dose. In the GENESIS study, compared with the placebo group, motixafotide in combination with filgrastim mobilized significantly more CD34+ HSPCs in two hematopoietic ablation procedures, while preferentially mobilizing more immunophenotyped and transcriptionally primitive HSPCs.
Motixafortide (BL-8040, BKT140) is a 14-residue biostable synthetic cyclic peptide that functions as a high-affinity antagonist of CXCR4. It blocks the binding of its ligand, SDF-1α/CXCL12. Motixafortide specifically triggers CXCR4-dependent cell death in leukemia and MM cells. It is indicated for use in combination with filgrastim to mobilize hematopoietic stem cells to the peripheral blood for collection and subsequent autologous transplantation in patients with multiple myeloma.

C97H144FN33O19S2

2159.5194

2158.074

C, 53.95; H, 6.72; F, 0.88; N, 21.40; O, 14.08; S, 2.97

664334-36-5

91865076

{4-Fluorobenzoyl}-Arg-Arg-{2-Naph-Ala}-Cys-Tyr-{Cit}-Lys-{d-Lys}-Pro-Tyr-Arg-{Cit}-Cys-Arg-NH2 (Disulfide bridge: Cys4-Cys13); N-(4-fluorobenzoyl)-L-arginyl-L-arginyl-3-(2-naphthyl)-L-alanyl-L-cysteinyl-L-tyrosyl-L-citrullyl-L-lysyl-L-lysyl-L-prolyl-L-tyrosyl-L-arginyl-L-citrullyl-L-cysteinyl-L-argininamide (4->13)-disulfide

RRXCYXKKPYRXCR; {4-Fluorobenzoyl}-RR-{2-Naph-Ala}-CY-{Cit}-K-{d-Lys}-PYR-{Cit}-CR-NH2 (Disulfide bridge: Cys4-Cys13)

White to off-white solid powder

1.5±0.1 g/cm3

1.703

-5.95

34

28

53

152

4500

14

C1C[C@H]2C(=O)N[C@H](C(=O)N[C@H](C(=O)N[C@H](C(=O)N[C@@H](CSSC[C@@H](C(=O)N[C@H](C(=O)N[C@H](C(=O)N[C@H](C(=O)N[C@H](C(=O)N2C1)CCCCN)CCCCN)CCCNC(=O)N)CC3=CC=C(C=C3)O)NC(=O)[C@H](CC4=CC5=CC=CC=C5C=C4)NC(=O)[C@H](CCCNC(=N)N)NC(=O)[C@H](CCCNC(=N)N)NC(=O)C6=CC=C(C=C6)F)C(=O)N[C@@H](CCCNC(=N)N)C(=O)N)CCCNC(=O)N)CCCNC(=N)N)CC7=CC=C(C=C7)O

JJVZSYKFCOBILL-MKMRYRNGSA-N

InChI=1S/C97H144FN33O19S2/c98-60-33-31-58(32-34-60)78(135)119-65(19-8-42-113-93(104)105)79(136)121-68(21-10-44-115-95(108)109)83(140)126-73(51-56-25-30-57-14-1-2-15-59(57)48-56)87(144)130-75-53-152-151-52-74(88(145)118-63(77(101)134)18-7-41-112-92(102)103)129-84(141)69(23-12-46-117-97(111)150)122-81(138)66(20-9-43-114-94(106)107)124-86(143)72(50-55-28-37-62(133)38-29-55)128-90(147)76-24-13-47-131(76)91(148)70(17-4-6-40-100)125-82(139)64(16-3-5-39-99)120-80(137)67(22-11-45-116-96(110)149)123-85(142)71(127-89(75)146)49-54-26-35-61(132)36-27-54/h1-2,14-15,25-38,48,63-76,132-133H,3-13,16-24,39-47,49-53,99-100H2,(H2,101,134)(H,118,145)(H,119,135)(H,120,137)(H,121,136)(H,122,138)(H,123,142)(H,124,143)(H,125,139)(H,126,140)(H,127,146)(H,128,147)(H,129,141)(H,130,144)(H4,102,103,112)(H4,104,105,113)(H4,106,107,114)(H4,108,109,115)(H3,110,116,149)(H3,111,117,150)/t63-,64-,65-,66-,67-,68-,69-,70-,71-,72-,73-,74-,75-,76-/m0/s1

(3S,6S,9S,12R,17R,20S,23S,26S,29S,34aS)-N-((S)-1-amino-5-guanidino-1-oxopentan-2-yl)-26,29-bis(4-aminobutyl)-17-((S)-2-((S)-2-((S)-2-(4-fluorobenzamido)-5-guanidinopentanamido)-5-guanidinopentanamido)-3-(naphthalen-2-yl)propanamido)-6-(3-guanidinopropyl)-3,20-bis(4-hydroxybenzyl)-1,4,7,10,18,21,24,27,30-nonaoxo-9,23-bis(3-ureidopropyl)triacontahydro-1H,16H-pyrrolo[2,1-p][1,2]dithia[5,8,11,14,17,20,23,26,29]nonaazacyclodotriacontine-12-carboxamide

BL8040; BL 8040; BL-8040; BKT140; BKT 140; BKT-140; TF 14016; TF14016; TF-14016; TN-14003; 4F-Benzoyl-TN14003; Aphexda. Motixafortide; 664334-36-5;

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)

DMSO : ≥ 100 mg/mL (~46.31 mM)
H2O : ~50 mg/mL (~23.15 mM)

Solubility in Formulation 1: 110 mg/mL (50.94 mM) in PBS (add these co-solvents sequentially from left to right, and one by one), clear solution; with sonication.

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