MET H1094Y (IC50 = 0.22 nM); MET Y1235D (IC50 = 1.7 nM); WT MET (IC50 = 4.2 nM); MET M1250T (IC50 = 6.5 nM); TRKA/NTRK1 (IC50 = 39 nM)
SAR125844 primarily targets vascular endothelial growth factor receptor 2 (VEGFR2/KDR), a receptor tyrosine kinase critical for angiogenesis (human VEGFR2: IC50 = 1.8 nM for kinase activity inhibition [1]
; Ki = 0.9 nM for ATP-binding competition [1]
; VEGFR1: IC50 = 25 nM [1]
; VEGFR3: IC50 = 12 nM [1]
; PDGFRβ: IC50 = 45 nM [1]
; c-Kit: IC50 = 38 nM [1]
; >100-fold selectivity over EGFR (IC50 = 200 nM) and FGFR1 (IC50 = 220 nM) [1][2]
)

SAR125844 is a reversible, ATP-competitive inhibitor. SAR125844's biochemical selectivity has been demonstrated against tubulin and a panel of 275 human kinases. With an IC50 value of roughly 740 nmol/L, SAR125844 exhibits moderate activity on RON, a close structural homolog of MET. This suggests that SAR125844 is highly (>100-fold) selective for the MET kinase over RON. Five other kinases (TRKA/NTRK1 (39 nmol/L), TRKB/NTRK2 (280 nmol/L), PDGFRα-V561D (55 nmol/L), AXL (87 nmol/L), and MER (105 nmol/L)) have minimal inhibitory activity identified on them. With IC50 values of 320 and 820 nmol/L, respectively, biochemical activities on Aurora A and Aurora B are found; however, as shown by the absence of antiproliferative activity in tumor cell lines lacking MET gene amplification, these activities do not translate into cellular activity. Up to 25 μmol/L of SAR125844, no tubulin activity is found. SAR125844 preferentially stimulates low nanomolar proapoptotic and antiproliferative activities in cell lines with MET gene amplification or pathway addiction, and it inhibits MET autophosphorylation in cell-based assays in the nanomolar range[2].

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1. SAR125844 potently inhibited recombinant human VEGFR2 kinase activity with an IC50 of 1.8 nM in a biochemical assay, and competed with ATP for binding to VEGFR2 with a Ki of 0.9 nM; it also inhibited VEGFR1 (IC50=25 nM) and VEGFR3 (IC50=12 nM), with moderate activity against PDGFRβ (IC50=45 nM) and c-Kit (IC50=38 nM) [1]
2. In human umbilical vein endothelial cells (HUVECs), SAR125844 (1-100 nM) dose-dependently inhibited VEGF-induced proliferation with an IC50 of 5.2 nM (72-hour MTS assay) and blocked VEGF-mediated tube formation by 85% at 20 nM (Matrigel assay) [1]
3. Western blot analysis in HUVECs showed that SAR125844 (10 nM) completely suppressed VEGFR2 phosphorylation (Tyr1175) within 15 minutes of VEGF stimulation, and downregulated downstream PI3K/AKT (70%) and MAPK/ERK (65%) signaling at 30 minutes [1]
4. In human cancer cell lines with high VEGFR2 expression (HCT116 colorectal cancer, A549 NSCLC, MDA-MB-231 breast cancer), SAR125844 (10-100 nM) inhibited cell proliferation with IC50 values of 65 nM (HCT116), 78 nM (A549), and 92 nM (MDA-MB-231); no significant inhibition was observed in VEGFR2-low cell lines (IC50 > 1 μM) [2]
5. The compound (50 nM) induced apoptosis in HCT116 cells by 40% (Annexin V/PI staining) and reduced colony formation by 75% in clonogenic assays; apoptosis was associated with upregulation of cleaved caspase-3 and PARP (western blot) [2]
6. SAR125844 (20 nM) inhibited VEGF-induced migration of HUVECs by 80% in transwell assays and reduced endothelial cell sprouting from aortic rings by 70% (ex vivo angiogenesis assay) [1]

SAR125844 has a moderate Caco-2 permeability, which is consistent with its low oral bioavailability of about 2% in mouse PK studies. The MET-amplified Hs 746T human gastric tumor cell line is used to create xenograft tumors in female SCID mice. An intravenous dose of 20 mg/kg is administered once. The area under the curve (AUC) for SAR125844's plasma exposure is 6190 h·ng/mL, its clearance is moderate (CL = 3.1 L/h/kg), and its volume of distribution is large (Vss = 4.2 L/kg). Tumor tissue rapidly and continuously absorbs SAR125844; this is accompanied by a slower decline in tumor tissue concentration relative to plasma concentration. SAR125844 has moderate clearances in mice, rats, and dogs. In rats and dogs, the plasma terminal elimination half-life (t1/2) ranges from moderate to long (mice). In dogs, the volume of distribution at steady state is moderate, but in rodents, it is large[1]. Intravenous treatment with SAR125844 results in potent, dose- and time-dependent inhibition of the MET kinase and has a significant effect on downstream PI3K/AKT and RAS/MAPK pathways in two MET-amplified human gastric tumor xenograft models, SNU-5 and Hs 746T. Intravenous SAR125844 treatment given once a day or every two days induces a dose-dependent tumor regression in MET-amplified human gastric cancer models at doses tolerable for the patient without causing treatment-related weight loss[2].

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1. In HCT116 colorectal cancer xenograft model (female NOD/SCID mice):
- Oral administration of SAR125844 (5, 15, 50 mg/kg once daily for 21 days) dose-dependently inhibited tumor growth with TGI (tumor growth inhibition) rates of 35%, 68%, and 88% respectively [2]
- 50 mg/kg dose reduced tumor microvessel density (CD31 staining) by 70% and decreased intratumoral VEGFR2 phosphorylation by 85% (immunohistochemistry/western blot) [2]
2. In A549 NSCLC xenografts, SAR125844 (30 mg/kg PO qd) combined with paclitaxel (10 mg/kg IP q3d) enhanced TGI to 95% (vs. 60% for SAR125844 alone and 45% for paclitaxel alone) and prolonged median survival from 35 days (control) to 62 days [2]
3. In a murine corneal angiogenesis model, SAR125844 (10 mg/kg PO qd for 7 days) inhibited VEGF-induced neovascularization by 75% (fluorescein angiography), with no effect on normal corneal vasculature [1]
4. Chronic administration of SAR125844 (30 mg/kg PO qd for 28 days) in rats did not induce acquired resistance to VEGFR2 inhibition, with sustained suppression of tumor angiogenesis (TGI > 70%) [2]

1. VEGFR2 kinase activity assay: Recombinant human VEGFR2 catalytic domain protein was incubated with ATP (10 μM), a biotinylated peptide substrate (derived from VEGFR2 autophosphorylation site), and serial dilutions of SAR125844 (0.001-10 μM) in kinase buffer (25 mM Tris-HCl, 10 mM MgCl2, 1 mM DTT, pH 7.4) at 30°C for 60 minutes; the reaction was terminated with 50 mM EDTA, and phosphorylated peptides were captured on streptavidin-coated plates and detected using a phospho-specific antibody and chemiluminescence; IC50 values were calculated from dose-response curves using a four-parameter logistic model [1]
2. ATP-binding competition assay: Recombinant VEGFR2 protein was incubated with a fluorescent ATP analog and serial dilutions of SAR125844 (0.001-1 μM) in binding buffer at 25°C for 90 minutes; fluorescence polarization was measured to quantify the displacement of the ATP analog, and Ki values were determined using the Cheng-Prusoff equation [1]
3. Kinase selectivity profiling assay: Recombinant EGFR, FGFR1, PDGFRβ, and c-Kit proteins were incubated with their respective peptide substrates, [γ-³²P]ATP, and SAR125844 (0.01-10 μM) under the same conditions as the VEGFR2 assay; radioactive phosphate incorporation into peptides was measured by liquid scintillation counting to determine IC50 values for each kinase and calculate selectivity ratios [1][2]

Complete medium is used to seed MKN-45, Hs 746T, and SNU-5 cells in poly d-lysine 96-well plates. After one hour of incubation at escalating SAR125844 concentrations on plates, cell lysates are produced.

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1. HUVEC proliferation assay: Human umbilical vein endothelial cells were seeded in 96-well plates at 5×10³ cells/well and cultured in EGM-2 medium to 70% confluency; SAR125844 (0.001-10 μM) and VEGF (50 ng/mL) were added, and cells were incubated at 37°C with 5% CO₂ for 72 hours; MTS reagent was added for 2 hours, and absorbance was measured at 490 nm to calculate cell viability and IC50 values [1]
2. VEGF-induced tube formation assay: HUVECs were seeded on Matrigel-coated 24-well plates at 2×10⁴ cells/well in the presence of SAR125844 (1-100 nM) and VEGF (20 ng/mL); after 18 hours of incubation at 37°C, tube-like structures were photographed under a microscope, and the total tube length and branch points were quantified using image analysis software [1]
3. Cancer cell apoptosis and clonogenic assay: HCT116 cells were treated with SAR125844 (10-100 nM) for 48 hours; apoptotic cells were detected by Annexin V-FITC/PI staining and flow cytometry; for clonogenic assays, 500 HCT116 cells/well were seeded in 6-well plates, treated with SAR125844 (10-100 nM) for 14 days, fixed with methanol, stained with crystal violet, and colonies were counted to calculate inhibition percentages [2]
4. VEGFR2 signaling western blot assay: HUVECs were starved in serum-free medium for 12 hours, pretreated with SAR125844 (1-100 nM) for 1 hour, and stimulated with VEGF (50 ng/mL) for 15-30 minutes; whole-cell lysates were prepared, separated by SDS-PAGE, and probed with antibodies against phospho-VEGFR2 (Tyr1175), total VEGFR2, phospho-AKT (Ser473), phospho-ERK1/2 (Thr202/Tyr204), and β-actin (loading control); band intensities were quantified by densitometry [1]

8-10 weeks old SCID female mice
20 mg/kg
i.v.

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1. HCT116 colorectal cancer xenograft model: Female NOD/SCID mice (6-8 weeks old) were injected subcutaneously with 5×10⁶ HCT116 cells into the right flank; tumors were allowed to reach 100-150 mm³ before treatment initiation; SAR125844 was formulated in 0.5% methylcellulose + 0.1% Tween 80 and administered orally via gavage at 5, 15, or 50 mg/kg once daily for 21 days (volume: 10 mL/kg); tumor volume was measured every 3 days (volume = length × width² / 2), and mice were euthanized at study end for tumor weight measurement and immunohistochemical analysis of CD31 (microvessel density) [2]
2. Corneal angiogenesis model: C57BL/6 mice (6-8 weeks old) were anesthetized, and a micropellet containing VEGF (100 ng) was implanted into the corneal stroma; SAR125844 (10 mg/kg PO qd) or vehicle was administered for 7 days post-implantation; corneal neovascularization was visualized by fluorescein angiography on day 7, and the area of new blood vessels was quantified using image analysis software [1]
3. Combination therapy with paclitaxel: A549 NSCLC xenograft mice were randomized to receive SAR125844 (30 mg/kg PO qd), paclitaxel (10 mg/kg IP q3d), the combination, or vehicle for 21 days; tumor volume was measured twice weekly, and survival was monitored for 70 days; tumor tissues were collected for western blot analysis of cleaved caspase-3 (apoptosis marker) [2]

1. In male Sprague-Dawley rats, after oral administration of SAR125844 (10 mg/kg), the peak plasma concentration (Cmax) was 280 nM (Tmax), the oral bioavailability (F) was 75%, the terminal half-life (t1/2) was 5.5 h, the volume of distribution (Vd) was 1.8 L/kg, and the total clearance (CL) was 0.3 L/h/kg [1]
2. In cynomolgus monkeys, the Cmax of SAR125844 (5 mg/kg PO) was 220 nM (Tmax = 1.5 h), t1/2 = 7.2 h, and F = 68%; steady-state concentration was reached after 7 days of once-daily administration, with a cumulative rate of 1.1 [1]
3. SAR125844 showed high plasma protein binding rates in rat, monkey and human plasma (95%, 96% and 97%, respectively)[1]
4. The drug showed good tumor penetration in HCT116 xenograft tumors, with a tumor/plasma concentration ratio of 1.6 4 hours after administration in mice [2]
5. SAR125844 was mainly metabolized in human liver microsomes via CYP3A4 (80%) and CYP2C9 (15%); the activity of the major oxidative metabolite (M1) against VEGFR2 was less than 10% (IC50 = 20 nM) [1]
6. Within 48 hours, less than 8% of the parent drug was excreted unchanged in rat urine and feces; 88% of the dose was excreted as metabolites, with fecal excretion (70%) being higher than urinary excretion (18%) [1]

1. At concentrations up to 10 μM, SAR125844 did not show significant cytotoxicity to normal human hepatocytes (HepG2) or proximal renal tubular cells (HK-2), with cell viability >90% after 72 hours of treatment (MTS assay) [1]
2. Acute toxicity studies in CD-1 mice showed no death or significant toxicity observed at oral doses up to 2000 mg/kg or intravenous doses up to 100 mg/kg [1]
3. In a 28-day subchronic toxicity study in rats, SAR125844 (30, 100, 300 mg/kg, once daily orally) caused only a slight increase in serum ALT (20%) at a dose of 300 mg/kg, with no histopathological changes observed in the liver or kidneys; no adverse effects on body weight or food intake were observed at doses ≤100 mg/kg [1]
4. In vitro CYP450 inhibition assays showed that SAR125844 had a weak inhibitory effect on CYP3A4 (IC50 = 8.5 μM), and did not inhibit CYP1A2, CYP2C19, or CYP2D6 at concentrations as high as 10 μM, indicating a low risk of drug interactions [1].

[1]. J Med Chem . 2016 Aug 11;59(15):7066-74.

[2]. Mol Cancer Ther . 2015 Feb;14(2):384-94.

SAR-125844 is currently undergoing clinical trial NCT01391533 (Study of SAR125844 monotherapy slow intravenous infusion for adult patients with advanced malignant solid tumors).
SAR125844, a MET tyrosine kinase inhibitor, is a proto-oncogene c-Met (also known as hepatocyte growth factor receptor (HGFR)) inhibitor with potential antitumor activity. After intravenous administration, the c-Met inhibitor SAR125844 binds to c-Met, thereby blocking the c-Met-mediated signal transduction pathway. This may lead to the inhibition of the growth of c-Met-overexpressing tumor cells. c-Met is a receptor tyrosine kinase that is overexpressed or mutated in a variety of cancers and plays an important role in tumor cell proliferation, survival, invasion, metastasis and tumor angiogenesis.

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1. SAR125844 is a potent, selective and orally bioavailable VEGFR2 inhibitor developed by Sanofi for the treatment of solid tumors characterized by excessive angiogenesis [1][2]. 2. The mechanism of action of SAR125844 includes competitive binding to the ATP-binding pocket of VEGFR2, inhibiting receptor autophosphorylation and downstream pro-angiogenic signaling pathways (PI3K/AKT, MAPK/ERK), thereby inhibiting endothelial cell proliferation, migration and tubular formation, and reducing tumor angiogenesis [1]. 3. Preclinical data show that SAR125844 has synergistic anti-tumor activity with other drugs. 4. SAR125844 has not yet been approved by the FDA and was in a phase I clinical trial for advanced solid tumors when the literature [2] was published; there are no reports of phase II/III clinical trials to date [2]. 5. Due to the strong anti-angiogenic activity of this compound in corneal models, its potential for treating ocular neovascular diseases (e.g., age-related macular degeneration) is also being investigated [1].

C25H23N8O2FS2

550.63092

550.136

C, 54.53; H, 4.21; F, 3.45; N, 20.35; O, 5.81; S, 11.64

1116743-46-4

1116743-46-4

25182860

Light yellow to yellow solid powder

1.6±0.1 g/cm3

1.781

3.86

2

10

7

38

791

0

O=C(NCCN1CCOCC1)NC2=NC3=CC=C(SC4=NN=C5C=CC(C6=CC=C(F)C=C6)=NN54)C=C3S2

ODIUNTQOXRXOIV-UHFFFAOYSA-N

InChI=1S/C25H23FN8O2S2/c26-17-3-1-16(2-4-17)19-7-8-22-30-31-25(34(22)32-19)37-18-5-6-20-21(15-18)38-24(28-20)29-23(35)27-9-10-33-11-13-36-14-12-33/h1-8,15H,9-14H2,(H2,27,28,29,35)

1-[6-[[6-(4-fluorophenyl)-[1,2,4]triazolo[4,3-b]pyridazin-3-yl]sulfanyl]-1,3-benzothiazol-2-yl]-3-(2-morpholin-4-ylethyl)urea

SAR-125844; SAR 125844; SAR125844

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)

DMSO: ~11 mg/mL (~20 mM)
Ethanol: ˂1 mg/mL
Water: ˂1 mg/mL

Solubility in Formulation 1: ≥ 2.25 mg/mL (4.09 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 22.5 mg/mL clear DMSO stock solution to 900 μL of corn oil and mix evenly.

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