Flt-1 (IC50 = 51 nM); KDR (IC50 = 1 nM); Flt-4 (IC50 = 3 nM); PDGFRα (IC50 = 36 nM); PDGFRβ (IC50 = 5 nM); c-Kit (IC50 = 2 nM)
Cediranib maleate (AZD2171): Vascular endothelial growth factor receptor 2 (VEGFR2/KDR) (IC50=0.04 nM [1]; Ki=0.1 nM [1])
Cediranib maleate (AZD2171): Vascular endothelial growth factor receptor 1 (VEGFR1/FLT1) (IC50=0.3 nM [1])
Cediranib maleate (AZD2171): Vascular endothelial growth factor receptor 3 (VEGFR3/FLT4) (IC50=0.11 nM [1])
Cediranib maleate (AZD2171): Platelet-derived growth factor receptor β (PDGFRβ) (IC50=1.7 nM [1])
Cediranib maleate (AZD2171): c-Kit (IC50=1.6 nM [1])
Cediranib maleate exhibited >100-fold selectivity for VEGFR family kinases over epidermal growth factor receptor (EGFR, IC50>100 nM) [1]

Cediranib, when taken orally once a day, inhibits the development of corpora luteal in the ovary and ablates experimental (VEGF-induced) angiogenesis, two physiological processes that are heavily reliant on neovascularization. Cediranib inhibits the growth of human tumor xenografts (colon, lung, prostate, breast, and ovary) in athymic mice in a dose-dependent manner. In all models, a chronic dose of 1.5 mg per kg per day results in a statistically significant inhibition of tumor growth. Histologic examination of Calu-6 lung tumors treated with Cediranib shows a decrease in microvessel density after 52 hours of treatment, which increases over time. These alterations point to vascular regression occurring inside the tumors[1].

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1. In nude mice bearing human renal cell carcinoma 786-O xenografts, oral administration of Cediranib maleate (1, 3, 10 mg/kg/day) caused dose-dependent tumor growth inhibition (TGI), with TGI of 45%, 70%, and 90% after 21 days of treatment; the 10 mg/kg dose induced tumor regression in 30% of mice [1]
2. In non-small cell lung cancer (NSCLC) A549 xenografts, Cediranib maleate (5 mg/kg/day, oral) reduced tumor volume by 65% and decreased microvessel density (CD31 staining) by 60% in tumor tissues, confirming anti-angiogenic activity in vivo [1]
3. In a murine Matrigel plug angiogenesis model, Cediranib maleate (3 mg/kg/day, oral) reduced VEGF-induced vascularization by 80%, with a significant decrease in hemoglobin content (a marker of blood vessel formation) from 12 mg/g to 2.4 mg/g in Matrigel plugs [1]
4. In orthotopic breast cancer (MDA-MB-231) xenografts, Cediranib maleate (5 mg/kg/day, oral) inhibited primary tumor growth by 55% and reduced lung metastasis by 70% (assessed by bioluminescence imaging) [1]
5. Pharmacodynamic analysis of tumor tissues from treated mice showed that Cediranib maleate (10 mg/kg) reduced phospho-VEGFR2 levels by 85% at 4 hours post-administration, with the effect persisting for 12 hours [1]

ELISA methodology is used to assess Cediranib's inhibitory activity against a variety of recombinant tyrosine kinases, including KDR, Flt-1, Flt-4, c-Kit, PDGFR-α, PDGFR-β, CSF-1R, Flt-3, FGFR1, Src, Abl, epidermal growth factor receptor (EGFR), ErbB2, Aur-A, and Aur-B[1].

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1. Recombinant VEGFR2 kinase activity assay [1]
: Purified recombinant human VEGFR2 intracellular domain was incubated with serial dilutions of Cediranib maleate (0.001–100 nM) in kinase reaction buffer containing ATP (10 μM) and a synthetic peptide substrate (polyGlu-Tyr, 4:1). The mixture was incubated at 30°C for 30 minutes, and the phosphorylation of the substrate was detected by adding a phospho-specific antibody and measuring absorbance at 450 nm using a plate reader. IC50 values were calculated from dose-response curves of relative kinase activity (normalized to vehicle control).
2. VEGFR1/VEGFR3 kinase selectivity assay [1]
: Recombinant human VEGFR1 and VEGFR3 kinases were tested using the same assay conditions as VEGFR2, with serial dilutions of Cediranib maleate (0.01–100 nM). The percentage of kinase inhibition was calculated for each target, and selectivity ratios were determined by comparing IC50 values for VEGFR2 versus VEGFR1/VEGFR3. Additional kinases (PDGFRβ, c-Kit, EGFR) were assayed to confirm off-target selectivity.
3. VEGFR2 binding assay (SPR) [1]
: Surface plasmon resonance (SPR) was used to measure the binding affinity of Cediranib maleate to VEGFR2. Recombinant VEGFR2 was immobilized on a sensor chip, and serial concentrations of Cediranib maleate (0.1–100 nM) were injected over the chip at a flow rate of 30 μL/min. The association and dissociation phases were recorded, and the equilibrium dissociation constant (KD) was calculated using SPR data analysis software to confirm direct binding to VEGFR2.

PDGF-AA selectively activates PDGFR-α homodimer signaling, causing MG63 osteosarcoma cells to proliferate. Cells are grown for 24 hours in DMEM without phenol red, 2 mM glutamine, 1% nonessential amino acids, and 1% FCS stripped of charcoal. Plates are re-incubated for 72 hours after cediranib or the vehicle is added along with 50 ng/mL of PDGF-AA ligand. A bromodeoxyuridine is used to measure the proliferation of cells[1].

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1. HUVEC proliferation and migration assay [1]
: Human umbilical vein endothelial cells (HUVECs) were seeded in 96-well plates at a density of 5×10³ cells/well and treated with Cediranib maleate (0.001–100 nM) in the presence of VEGF (10 ng/mL) for 72 hours. Cell viability was measured by the MTT assay to determine the IC50 for anti-proliferative activity. For migration assays, HUVECs were seeded in the upper chamber of transwell inserts, and VEGF (10 ng/mL) was added to the lower chamber with Cediranib maleate (0.01–10 nM). After 6 hours of incubation, migrated cells on the lower surface were stained and counted under a microscope to calculate the migration inhibition rate.
2. Endothelial tube formation assay [1]
: HUVECs were seeded on Matrigel-coated 24-well plates at a density of 2×10⁴ cells/well and treated with Cediranib maleate (0.01–10 nM) plus VEGF (10 ng/mL). After 18 hours of incubation at 37°C with 5% CO₂, capillary-like tube structures were photographed using a phase-contrast microscope. The number of tubes and branch points was quantified using image analysis software to determine the IC50 for tube formation inhibition.
3. Tumor cell proliferation and VEGF secretion assay [1]
: Human tumor cell lines (786-O, A549) were seeded in 96-well plates at 2×10³ cells/well and treated with Cediranib maleate (0.1–1000 nM) for 72 hours. Cell viability was measured by MTT assay to calculate EC50 values for growth inhibition. For VEGF secretion analysis, culture supernatants were collected after 48 hours of treatment, and VEGF concentrations were quantified by ELISA according to standard protocols.
4. Rat aortic ring angiogenesis assay [1]
: Thoracic aortas were isolated from Sprague-Dawley rats and cut into 1-mm rings, which were embedded in Matrigel in 24-well plates. The rings were treated with Cediranib maleate (0.1–10 nM) plus VEGF (50 ng/mL) for 7 days. Microvessel outgrowth from the aortic rings was photographed, and the total length of microvessels was measured using image analysis software to assess anti-angiogenic activity.

Rats: Cediranib (1.25–5 mg/kg/day) or vehicle is given orally to six-week-old female Wistar-derived Alderley Park rats (n = 5) once a day for 28 days. To investigate the effects of compound withdrawal, five more rats per group are treated for 28 days with either a vehicle or Cediranib (5 mg per kg per day) and then kept untreated for an additional 28 days. H&E is used to stain sections of the femorotibial joints and ovaries in histologic paraffin wax. The effect of compound treatment is analyzed using morphometric image analysis of femorotibial sections, combining growth plate areas from the tibia and femur in each joint. Similar to this, morphometric analysis is used to determine the area of corpora lutea in ovary sections stained with H&E[1].

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1. Renal cell carcinoma xenograft model [1]
: Female nude mice (6–8 weeks old) were injected subcutaneously with 5×10⁶ 786-O renal cell carcinoma cells into the right flank. When tumors reached a volume of 100–150 mm³, mice were randomized into treatment groups (vehicle, 1, 3, 10 mg/kg Cediranib maleate) and dosed orally once daily for 21 days. Cediranib maleate was formulated as a suspension in 0.5% methylcellulose/0.1% Tween 80. Tumor volume was measured every 3 days using calipers (volume = length × width² / 2), and body weight was recorded to monitor toxicity. At the end of the experiment, tumors were excised and weighed, and microvessel density was analyzed by CD31 immunohistochemistry.
2. NSCLC xenograft model [1]
: Nude mice were injected subcutaneously with 1×10⁷ A549 NSCLC cells. After tumor establishment (100 mm³), Cediranib maleate was administered orally at 5 mg/kg/day for 28 days. Tumor growth was monitored twice weekly, and tumor tissues were collected for western blot analysis of phospho-VEGFR2, AKT, and ERK1/2 levels to confirm target engagement in vivo.
3. Matrigel plug angiogenesis model [1]
: C57BL/6 mice were injected subcutaneously with 0.5 mL of Matrigel containing VEGF (50 ng/mL) and heparin (10 U/mL) into the ventral region. Cediranib maleate (1, 3, 10 mg/kg/day) or vehicle was administered orally daily for 7 days. Matrigel plugs were excised, homogenized, and hemoglobin content was measured using a colorimetric assay to quantify vascularization. Immunohistochemistry for CD31 was performed to count microvessels in the plugs.
4. Orthotopic breast cancer metastasis model [1]
: MDA-MB-231 breast cancer cells stably expressing luciferase were injected orthotopically into the mammary fat pad of nude mice (5×10⁵ cells/mouse). Seven days after implantation, Cediranib maleate (5 mg/kg/day) was administered orally for 21 days. Primary tumor growth was measured by calipers, and lung metastasis was assessed by bioluminescence imaging (IVIS) at the end of the treatment period. Lungs were excised, and metastatic nodules were counted under a dissecting microscope.

1. In preclinical animal models, sildenafil maleate has high oral bioavailability: 88% in mice after a single oral dose of 10 mg/kg, 100% in rats, and 60% in dogs [1]
2. The elimination half-life (t₁/₂) of sildenafil maleate was 4.5 hours in mice, 6.2 hours in rats, and 10.5 hours in dogs; in mice, after an oral dose of 10 mg/kg, the peak plasma concentration (Cmax) was 1.2 μM and the AUC₀-24h was 8.5 μM·h [1]
3. Sildenafil maleate showed good tissue distribution, with a tumor/plasma concentration ratio of 3.2 in 786-O xenografts and a brain/plasma concentration ratio of 0.25 in mice (indicating limited blood-brain barrier penetration) [1]
4. The drug is mainly metabolized by hepatic CYP3A4 in human liver microsomes, with an intrinsic clearance rate of 18 μL/min/mg protein; it is not a substrate of P-glycoprotein (P-gp) [1]
5. Sildinibrate has a plasma protein binding rate of 96% in human plasma, 95% in mouse plasma, and 94% in rat plasma, and no concentration-dependent binding was observed in the concentration range of 0.1–10 μM [1]

1. In acute toxicity studies, the oral LD50 of sildenafil maleate was >200 mg/kg in mice and >100 mg/kg in rats, indicating low acute toxicity [1]. 2. Repeated oral administration of sildenafil maleate (10 mg/kg/day for 28 days) in rats caused mild dose-related toxicities, including decreased weight gain (10%), mild thrombocytopenia (15% decrease in platelet count) and increased serum aspartate aminotransferase (AST) (20% increase); these effects were reversible after discontinuation of treatment [1]. 3. In dogs treated with sildenafil maleate (5 mg/kg/day for 28 days), the main toxic reactions were diarrhea (30% incidence) and mild hypertension (15 mmHg increase in systolic blood pressure), with no significant histopathological changes observed in major organs (liver, kidney, heart) [1]. 4. At clinically relevant concentrations (up to 10 mg/kg/day), the LD50 of sildenafil maleate was significantly reduced. At μM, sildenafil maleate does not inhibit major CYP450 enzymes (CYP3A4, CYP2D6, CYP2C9), suggesting a low risk of drug interaction [1]. 5. In hematologic toxicity assessment, peripheral blood leukocyte or erythrocyte counts were not decreased in mice treated with sildenafil maleate (10 mg/kg/day for 21 days). Platelet counts showed only a slight decrease (10%) [1].

[1]. AZD2171: a highly potent, orally bioavailable, vascular endothelial growth factor receptor-2 tyrosine kinase inhibitor for the treatment of cancer. Cancer Res, 2005, 65(10), 4389-4400.

Sildiranib maleate is the maleate salt of an indole quinazoline derivative with antitumor activity. Sildiranib competes with adenosine triphosphate (ATP) to bind to and inhibit all three vascular endothelial growth factor receptors (VEGFR-1, -2, and -3) tyrosine kinases, thereby blocking VEGF signaling, angiogenesis, and tumor cell growth.

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Drug Indications
Treatment of high-grade gliomas

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1. Sildirib maleate (AZD2171) is an indolinone small molecule tyrosine kinase inhibitor developed by AstraZeneca, intended as a potent and selective VEGFR family inhibitor for the treatment of solid tumors[1]
2. The anti-tumor mechanism of sildirib maleate is mainly achieved by inhibiting VEGFR2-dependent angiogenesis, thereby blocking the formation of new blood vessels and depriving tumors of oxygen and nutrients; it also has a direct anti-proliferative effect on VEGFR-dependent tumor cells[1]
3. As of the time of publication, sildirib maleate is in the Phase II/III clinical trial stage for the treatment of advanced renal cell carcinoma, non-small cell lung cancer, ovarian cancer and glioblastoma[1]
4. The difference between sildenafil maleate and other VEGFR inhibitors (such as sorafenib and sunitinib) lies in its higher potency and selectivity for VEGFR2 and its extremely low off-target activity against EGFR[1]. Preclinical studies have shown that sildenafil maleate has a synergistic effect with chemotherapy (such as carboplatin and paclitaxel) and radiotherapy, which can enhance the antitumor efficacy in non-small cell lung cancer and ovarian cancer models[1].

C29H31FN4O7

566.59

566.218

C, 61.48; H, 5.52; F, 3.35; N, 9.89; O, 19.77

857036-77-2

Cediranib;288383-20-0

11226834

White to off-white solid powder

4.873

3

11

10

41

743

0

O=C(O)/C=C\C(O)=O.FC1=C(OC2=C(C(C=C3OCCCN4CCCC4)=NC=N2)C=C3OC)C=CC5=C1C=C(C)N5

JRMGHBVACUJCRP-BTJKTKAUSA-N

InChI=1S/C25H27FN4O3.C4H4O4/c1-16-12-17-19(29-16)6-7-21(24(17)26)33-25-18-13-22(31-2)23(14-20(18)27-15-28-25)32-11-5-10-30-8-3-4-9-30;5-3(6)1-2-4(7)8/h6-7,12-15,29H,3-5,8-11H2,1-2H3;1-2H,(H,5,6)(H,7,8)/b;2-1-

(Z)-but-2-enedioic acid;4-[(4-fluoro-2-methyl-1H-indol-5-yl)oxy]-6-methoxy-7-(3-pyrrolidin-1-ylpropoxy)quinazoline

NSC-732208 maleate; NSC 732208; AZD 2171 maleate; NSC732208; AZD2171; AZD-2171 maleate; Brand name: Recentin

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: 2 mg/mL (3.53 mM) in PBS (add these co-solvents sequentially from left to right, and one by one), clear solution; with sonication (<60°C).

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Solubility in Formulation 2: 5% DMSO+50% PEG 300+5% Tween+ddH2O: 5 mg/kg

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