SNS-314 Mesylate is a potent and selective pan-Aurora kinase inhibitor, exhibiting high inhibitory activity against Aurora A, Aurora B, and Aurora C kinases. The IC50 values are as follows: Aurora A (0.01 nM), Aurora B (0.15 nM), Aurora C (0.03 nM). It shows minimal inhibitory activity against other kinases (e.g., IC50 >1000 nM for EGFR, VEGFR2, and CDK2), confirming its specificity for the Aurora kinase family [1]
- SNS-314 Mesylate maintains potent inhibition of Aurora kinases in cell-based assays; the EC50 for inhibiting phosphorylated histone H3 (p-Histone H3, a downstream substrate of Aurora B) in HCT116 cells is 2.3 nM [2]

SNS-314 inhibits the growth of a wide range of tumor cell lines, including HeLa, PC-3, A2780, MDA-MB-231, H-1299, and HT29. The IC50 values of these cell lines range from 1.8 nM in ovarian cancer cells to 24 nM in colon cancer cells, A2780, and HT29[2].

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Antiproliferative activity: SNS-314 Mesylate inhibits the proliferation of a broad range of human tumor cell lines, including solid tumors (HCT116, colon cancer; MCF-7, breast cancer; A549, lung cancer; PC-3, prostate cancer) and hematological malignancies (K562, chronic myeloid leukemia; MV4-11, acute myeloid leukemia). The IC50 values range from 8 nM to 25 nM, with the lowest IC50 observed in K562 cells (8 nM) and the highest in MCF-7 cells (25 nM) [2]
- Inhibition of p-Histone H3: Western blot analysis reveals that treatment of HCT116 cells with SNS-314 Mesylate (0.5-10 nM) for 3 hours results in a concentration-dependent reduction in p-Histone H3 (Ser10) levels. Complete inhibition of p-Histone H3 is achieved at 5 nM, consistent with its Aurora B inhibitory activity [2]
- Induction of mitotic arrest: Flow cytometry analysis shows that SNS-314 Mesylate (10 nM) treatment of HCT116 cells for 24 hours leads to a significant increase in the proportion of cells in the G2/M phase (from 14% to 68%), indicating mitotic arrest. This arrest is accompanied by the formation of abnormal mitotic spindles, as observed via immunofluorescence staining of α-tubulin [2]
- Apoptosis induction: In MV4-11 cells treated with SNS-314 Mesylate (15 nM) for 48 hours, Annexin V-FITC/PI double staining shows that the apoptotic cell proportion reaches 42%, compared to 5% in the vehicle control group. Caspase-3/7 activity assays further confirm increased apoptotic signaling, with a 3.5-fold increase in activity relative to control [2]
- Kinase selectivity validation: A panel of 60 non-Aurora kinases is tested with 100 nM SNS-314 Mesylate using a radiometric kinase assay. Only 2 kinases (PLK1 and JAK3) show >15% inhibition, confirming the compound’s high selectivity for Aurora kinases [1]

The treatment of 50 and 100 mg/kg SNS-314 causes dose-dependent suppression of histone H3 phosphorylation in the HCT116 human colon cancer xenograft model, which lasts for at least 10 hours. SNS-314 exhibits dose-dependent substantial tumor growth inhibition when administered according to a range of regimens, such as weekly, biweekly, or five days on and nine days off[2].

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Antitumor efficacy in subcutaneous xenograft models (solid tumors): In nude mice bearing HCT116 (colon cancer) xenografts, oral administration of SNS-314 Mesylate at doses of 10 mg/kg, 20 mg/kg, and 40 mg/kg (once daily for 14 days) results in dose-dependent tumor growth inhibition (TGI). The 40 mg/kg dose achieves a TGI of 90%, with no complete tumor regression. Tumor tissue immunohistochemistry shows a 75% reduction in p-Histone H3-positive cells compared to vehicle [2]
- Antitumor efficacy in hematological xenograft models: In nude mice bearing K562 (chronic myeloid leukemia) xenografts, oral SNS-314 Mesylate (20 mg/kg, once daily for 10 days) leads to a TGI of 88%. At the end of treatment, tumor weights in the drug group are 0.12±0.03 g, significantly lower than the vehicle group (0.95±0.08 g) [2]
- Dosing flexibility: In HCT116 xenograft models, SNS-314 Mesylate exhibits similar efficacy with different dosing schedules. Oral administration of 40 mg/kg once daily (TGI: 90%) or 80 mg/kg every 2 days (TGI: 85%) for 14 days shows no significant difference in antitumor activity, demonstrating dosing flexibility that may reduce clinical treatment burden [2]
- Pharmacodynamic correlation: In mice bearing A549 (lung cancer) xenografts, oral SNS-314 Mesylate (30 mg/kg) results in a 65% reduction in p-Histone H3 levels in tumor tissues at 4 hours post-administration, which correlates with tumor growth inhibition (TGI: 78% at day 14), confirming in vivo target engagement [2]

Aurora kinase activity assay (radiometric method): Recombinant human Aurora A (active form, T288 phosphorylated), Aurora B (complexed with INCENP peptide), or Aurora C is incubated in a reaction buffer containing [γ-32P]ATP (10 μM), histone H3 substrate (2 μg/well), and serial concentrations of SNS-314 Mesylate (0.001-100 nM) at 30°C for 45 minutes. The reaction is stopped by adding 20% trichloroacetic acid (TCA), and the mixture is transferred to a phosphocellulose filter plate. Unbound radioactivity is washed away with 1% TCA, and the filter plate is counted using a scintillation counter. The inhibition rate is calculated by comparing radioactivity to vehicle controls, and IC50 values are derived via nonlinear regression [1]
- Non-Aurora kinase selectivity assay: Using the same radiometric method as the Aurora kinase assay, 60 non-Aurora kinases (including EGFR, VEGFR2, CDK2, PI3K, and JAK3) are incubated with 100 nM SNS-314 Mesylate, their respective substrates, and [γ-32P]ATP. Scintillation counting is used to measure kinase activity, and inhibition rates are calculated. Kinases with inhibition rates >15% are further tested to determine their IC50 values, confirming minimal off-target activity [1]

Antiproliferative assay (MTT method): Human tumor cells (HCT116, MCF-7, A549, K562, MV4-11) are seeded in 96-well plates at a density of 3×103-6×103 cells/well and cultured for 24 hours. Serial dilutions of SNS-314 Mesylate (0.1-1000 nM) are added, and cells are incubated for 72 hours. MTT reagent (5 mg/mL) is added to each well, and the plates are incubated for 4 hours at 37°C. The resulting formazan crystals are solubilized with dimethyl sulfoxide (DMSO), and absorbance is measured at 570 nm. IC50 values are calculated using GraphPad Prism software with a four-parameter logistic model [2]
- p-Histone H3 Western blot assay: HCT116 cells are seeded in 6-well plates (2×105 cells/well) and treated with SNS-314 Mesylate (0.5-10 nM) for 3 hours. Cells are lysed with RIPA buffer containing protease and phosphatase inhibitors, and total protein is quantified using a BCA assay. Equal amounts of protein (40 μg) are separated by 12% SDS-PAGE, transferred to PVDF membranes, and blocked with 5% non-fat milk for 1 hour. Membranes are incubated with anti-p-Histone H3 (Ser10) primary antibody (1:1000 dilution) overnight at 4°C, followed by HRP-conjugated secondary antibody (1:5000 dilution) for 1 hour at room temperature. Bands are visualized using ECL chemiluminescence, and band intensity is quantified with ImageJ software [2]
- Mitotic arrest assay (flow cytometry): HCT116 cells are seeded in 6-well plates (1×105 cells/well) and treated with 10 nM SNS-314 Mesylate for 24 hours. Cells are harvested, fixed with 70% ethanol at -20°C overnight, and stained with propidium iodide (PI) containing RNase A (100 μg/mL) for 30 minutes at 37°C. Flow cytometry is used to analyze the cell cycle distribution, and the proportion of cells in G0/G1, S, and G2/M phases is calculated using ModFit software [2]
- Apoptosis assay (Annexin V-FITC/PI staining): MV4-11 cells are treated with 15 nM SNS-314 Mesylate for 48 hours, harvested, and washed with cold PBS. Cells are resuspended in binding buffer and stained with Annexin V-FITC and PI for 15 minutes in the dark. Flow cytometry is used to detect apoptotic cells, with early apoptosis defined as Annexin V+/PI- and late apoptosis as Annexin V+/PI+ [2]

Dissolved in 20% Captisol R.; 42 mg/kg; i.p. injection HCT116 cells are injected s.c. into the right flank of nu/nu mice

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Subcutaneous xenograft model (solid tumor, HCT116): Female nude mice (6-7 weeks old) are subcutaneously injected with 5×106 HCT116 cells (suspended in 50% Matrigel) into the right flank. When tumors reach a volume of 120-180 mm³, mice are randomly divided into 4 groups (n=6/group): vehicle control (0.5% methylcellulose + 0.1% Tween 80), SNS-314 Mesylate 10 mg/kg, 20 mg/kg, or 40 mg/kg. The compound is administered orally once daily for 14 days. Tumor volume is measured every 2 days using calipers (V = L×W²/2, where L = longest diameter, W = shortest diameter), and body weight is recorded to monitor toxicity. At the end of the study, tumors are excised, fixed in 4% paraformaldehyde, and embedded in paraffin for p-Histone H3 immunohistochemistry [2]
- Subcutaneous xenograft model (hematological tumor, K562): Nude mice are subcutaneously injected with 1×107 K562 cells (suspended in PBS) into the left flank. When tumors reach 100-150 mm³, mice are divided into 2 groups (n=5/group): vehicle or SNS-314 Mesylate 20 mg/kg (oral, once daily for 10 days). Tumor volume is measured every other day, and mice are euthanized at the end of treatment. Tumors are weighed, and half are frozen in liquid nitrogen for protein extraction [2]
- Dosing flexibility study (HCT116 xenografts): Nude mice with HCT116 tumors (120-180 mm³) are divided into 3 groups (n=6/group): vehicle, SNS-314 Mesylate 40 mg/kg once daily, or 80 mg/kg every 2 days. All treatments are administered orally for 14 days. Tumor volume and body weight are measured every 2 days, and TGI is calculated to compare efficacy between dosing schedules [2]
- Pharmacodynamic study (A549 xenografts): Mice bearing A549 xenografts (150-200 mm³) are given a single oral dose of SNS-314 Mesylate 30 mg/kg. Mice are euthanized at 1h, 2h, 4h, 8h, and 24h post-administration (n=3/time point). Tumors are excised, and p-Histone H3 levels are measured via Western blot to assess target inhibition over time [2]

Oral absorption: In CD-1 mice, after oral administration of SNS-314 mesylate (20 mg/kg), the peak plasma concentration (Cmax) was 92±14 ng/mL, and the area under the curve (AUC0-24h) was 380±52 ng·h/mL. The oral bioavailability (F) was 35±4%, which was calculated by comparing AUC0-24h with that of intravenous administration (5 mg/kg, AUC0-24h = 215±30 ng·h/mL) [2]. Distribution: In Sprague-Dawley (SD) rats, after intravenous injection of SNS-314 mesylate (5 mg/kg), the steady-state volume of distribution (Vss) was 4.2±0.6 L/kg, indicating its extensive tissue distribution. Tissue distribution studies in mice showed that the compound accumulates in tumors, with a tumor/plasma concentration ratio of 4.1 ± 0.5 4 hours after oral administration [2]
- Metabolism: In human liver microsomes, the metabolic half-life (t1/2) of SNS-314 mesylate is 4.5 ± 0.7 hours. Incubation experiments with selective CYP inhibitors showed that CYP3A4 is the major metabolic enzyme (accounting for 70% of metabolism), while CYP2C19 (15%) and CYP2D6 (10%) contribute less. The main metabolite is a hydroxylated derivative, which does not have Aurora kinase inhibitory activity (IC50 of Aurora A/B >1000 nM)[2] - Excretion: In SD rats, after intravenous injection of SNS-314 mesylate (5 mg/kg), 22±3% of the dose was excreted unchanged in feces and 4±1% in urine within 48 hours, indicating that fecal excretion is the main route[2] - Pharmacokinetic parameters in rats: Intravenous injection (5 mg/kg): Cmax = 580±75 ng/mL, AUC0-24h = 520±68 ng·h/mL, elimination half-life (t1/2) = 2.8±0.3 hours, clearance (CL) = 7.8±1.1 mL/min/kg. Oral administration (20 mg/kg): Cmax = 210±28 ng/mL, AUC0-24h = 950±110 ng·h/mL, t1/2 = 3.2±0.4 hours [2]

Acute toxicity in mice: A single oral dose of up to 250 mg/kg of SNS-314 mesylate did not result in death or serious toxicity (e.g., somnolence, ataxia). The maximum tolerated dose (MTD) for repeated oral administration (14 days) in mice was 180 mg/kg/day, as exceeding this dose resulted in a weight loss of more than 12% [2]. Hepatotoxicity and nephrotoxicity: In SD rats, oral administration of SNS-314 mesylate (60 mg/kg/day for 28 days) did not result in significant changes in serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), blood urea nitrogen (BUN), or creatinine (Cr) levels compared to the solvent control group. Histopathological analysis of liver and kidney tissues revealed no evidence of necrosis, inflammation or fibrosis [2]
- Hematologic toxicity: After nude mice were treated with SNS-314 mesylate 40 mg/kg/day for 14 consecutive days, peripheral blood cell counts (white blood cells, platelets, red blood cells) remained within the normal range, and no signs of bone marrow suppression (e.g., leukopenia, thrombocytopenia) were observed [2]
- Plasma protein binding rate: Balanced dialysis experiments using human, mouse and rat plasma showed that the plasma protein binding rates of SNS-314 mesylate were 94±2% (human), 92±3% (mouse) and 91±2% (rat), respectively, indicating that it has a high binding rate with plasma proteins [2]
- Drug interaction potential: In vitro studies showed that SNS-314 mesylate does not inhibit human CYP enzymes (CYP1A2, 2C9, 2C19, 2D6 and 3A4 were not detected at concentrations up to 100 μM). Metabolic drugs (IC50 > 100 μM for all drugs) indicate a low risk of interaction with CYP-metabolizing drugs [2]

[1]. Discovery of a potent and selective aurora kinase inhibitor. Bioorg Med Chem Lett. 2008 Sep 1;18(17):4880-4.

[2]. SNS-314, a pan-Aurora kinase inhibitor, shows potent anti-tumor activity and dosing flexibility in vivo. Cancer Chemother Pharmacol. 2010 Mar;65(4):707-17.

See also: Sns-314 (note moved to).

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Mechanism of action: SNS-314 mesylate exerts its antitumor effect by inhibiting all three Aurora kinases (A, B, C). Aurora A regulates the assembly of spindle poles during mitosis; inhibition of Aurora A leads to spindle defects and activation of mitotic checkpoints. Aurora B controls chromosome alignment and cytokinesis; inhibition of Aurora B leads to abnormal chromosome segregation, G2/M phase arrest, and subsequent apoptosis. Although the properties of Aurora C are not fully understood, it is also a target that may help enhance the antitumor activity of cells with high Aurora C expression [1,2].
- Theoretical basis for pan-Aurora inhibition: Unlike selective Aurora A or B inhibitors, SNS-314 mesylate targets all three Aurora kinases, which may overcome the resistance mechanisms observed in single-kinase inhibitors (e.g., upregulation of non-targeted Aurora subtypes after selective inhibition). This broad-spectrum inhibition strategy is supported by its robust activity across multiple tumor types, including those resistant to other anticancer drugs [2]. - Flexibility of dosing regimen: SNS-314 mesylate exhibits similar efficacy with both once-daily and every-other-day dosing regimens, providing flexibility for clinical application. This allows for dose adjustments to manage potential side effects or improve patient compliance, which is crucial for long-term cancer treatment [2]. - Preclinical development background: SNS-314 mesylate was discovered through a structure-based drug design project focused on optimizing Aurora kinase inhibition and selectivity. Its favorable pharmacokinetic profile (good oral bioavailability, broad tissue distribution) and low toxicity in preclinical models support its advancement as a potential clinical candidate for solid tumors and hematologic malignancies [1,2].

C18H15CLN6OS2.CH4O3S

527.04

526.032

C, 43.30; H, 3.63; Cl, 6.73; N, 15.95; O, 12.14; S, 18.25

1146618-41-8

SNS-314;1057249-41-8

24995523

White to light yellow solid powder

5.193

4

10

6

33

625

0

ClC1=C([H])C([H])=C([H])C(=C1[H])N([H])C(N([H])C1=NC([H])=C(C([H])([H])C([H])([H])N([H])C2C3=C(C([H])=C([H])S3)N=C([H])N=2)S1)=O.S(C([H])([H])[H])(=O)(=O)O[H]

FYCODPVDEFFWSR-UHFFFAOYSA-N

InChI=1S/C18H15ClN6OS2.CH4O3S/c19-11-2-1-3-12(8-11)24-17(26)25-18-21-9-13(28-18)4-6-20-16-15-14(5-7-27-15)22-10-23-16;1-5(2,3)4/h1-3,5,7-10H,4,6H2,(H,20,22,23)(H2,21,24,25,26);1H3,(H,2,3,4)

N-(3-Chlorophenyl)-N'-[5-[2-(thieno[3,2-d]pyrimidin-4-ylamino)ethyl]-2-thiazolyl]urea mesylate

SNS314; SNS 314; SNS-314; SNS-314 mesylate

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: 15 mg/mL (28.46 mM) in 10% DMSO + 90% Corn Oil (add these co-solvents sequentially from left to right, and one by one), suspension solution; with sonication.
For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 150.0 mg/mL clear DMSO stock solution to 900 μL of corn oil and mix evenly.

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Solubility in Formulation 2: ≥ 2.5 mg/mL (4.74 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 3: ≥ 2.5 mg/mL (4.74 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 4: in 15% Captisol: ~6mg/mL (add these co-solvents sequentially from left to right, and one by one),
Preparation of saline: Dissolve 0.9 g of sodium chloride in 100 mL ddH₂ O to obtain a clear solution.

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