In GIST 882, thyroid TT, MDA-MB-231, HepG2, A375, and SW620 cells, regorafenib mesylate (0–10 μM, 96 h) has anti-proliferative action [1]. In addition to inhibiting FGFR and pERK1/2, regorafenib mesylate (0-3000 nM, 30 minutes) also prevents VEGFR2, TIE2, and PDGFR-β from autophosphorylating[1]. Hep3B cell growth is inhibited by regorafenib mesylate in a concentration-dependent manner, with an IC50 of 5 μM. The JNK target phosphorylated c-Jun is then upregulated by regorafenib in Hep3B cells, but not total c-Jun [2].

Regorafenib mesylate (10 mg/kg, PO, as a single dosage or daily for 4 days) reduces tumor vasculature and tumor development in the rat GS9L glioblastoma model [1]. Regorafenib mesylate (0-100 mg/kg, oral, qd × 9) demonstrates anti-tumor and anti-angiogenic actions in Colo-205, MDA-MB-231 and 786-O models [1].

Cell Proliferation Assay[1]
Cell Types: GIST 882, Thyroid TT, MDA-MB-231, HepG2, A375 and SW620 Cell
Tested Concentrations: 10 μM and 5 nM
Incubation Duration: 96 hrs (hours)
Experimental Results: In GIST 882, Thyroid TT, MDA- For MB-231, HepG2, A375 and SW620 cells, the IC50 values are 45 ± 20, 34 ± 8, 401 ± 88, 560 ± 200, 900, 967 ± 287 nM. respectively.

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Western Blot Analysis[1]
Cell Types: NIH-3T3/VEGFR2 cells, (CHO)-TIE2 cells, HAoSMCs cells, MCF-7 cells
Tested Concentrations: 0, 10, 30, 100, 300, 1000, 3000 nM
Incubation Duration: 30 Minute
Experimental Results: Inhibits autophosphorylation of VEGFR2, TIE2, and PDGFR-β with IC50 values of 3, 31, and 90 nM, respectively, inhibits FGFR signaling in FGF10-stimulated MCF-7 breast cancer (BC) cells, and shows inhibition Phosphorylates FGFR substrate 2 (pFRS2) and the downstream signaling kinase pERK1/2.

Animal/Disease Models: Rat GS9L glioblastoma xenograft[1]
Doses: 10 mg/kg
Route of Administration: po (po (oral gavage)) single dose or one time/day for 4 days
Experimental Results: Inhibition of rat GS9L glioblastoma Tumor vasculature and tumor growth in models.

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Animal/Disease Models: Female athymic NCr nu/nu (nude) mice, various xenograft models, including those derived from CRC (Colo-205), BC (MDA-MB-231) and RCC (786-O) tumors [1]
Doses: 0, 3, 10, 30, 100 mg/kg
Route of Administration: po (po (oral gavage)) qd × 9
Experimental Results: Effectively inhibited the growth of Colo-205, MDA-MB-231 and 786-O models. Dramatically reduces tumor MVA, effectively inhibits the RAF/MEK/ERK signaling cascade reaction, and Dramatically inhibits tumor cell proliferation.

Absorption, Distribution and Excretion
Cmax = 2.5 μg/mL; Tmax = 4 hours; AUC = 70.4 μg*h/mL; Cmax, steady-state = 3.9 μg/mL; AUC, steady-state = 58.3 μg*h/mL; The mean relative bioavailability of tablets compared to an oral solution is 69% to 83%.
Approximately 71% of a radiolabeled dose was excreted in feces (47% as parent compound, 24% as metabolites) and 19% of the dose was excreted in urine (17% as glucuronides) within 12 days after administration of a radiolabeled oral solution at a dose of 120 mg.
Regorafenib undergoes enterohepatic circulation with multiple plasma concentration peaks observed across the 24-hour dosing interval.

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Metabolism / Metabolites
Regorafenib is metabolized by CYP3A4 and UGT1A9. The main circulating metabolites of regorafenib measured at steady-state in human plasma are M-2 (N-oxide) and M-5 (N-oxide and N-desmethyl), both of them having similar in vitro pharmacological activity and steady-state concentrations as regorafenib. M-2 and M-5 are highly protein bound (99.8% and 99.95%, respectively). Regorafenib is an inhibitor of P-glycoprotein, while its active metabolites M-2 (N-oxide) and M-5 (N-oxide and N-desmethyl) are substrates of P-glycoprotein.

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Biological Half-Life
Regorafenib, 160 mg oral dose = 28 hours (14 - 58 hours); M2 metabolite, 160 mg oral dose = 25 hours (14-32 hours); M5 metabolite, 160 mg oral dose = 51 hours (32-72 hours);

Hepatotoxicity
In large clinical trials of regorafenib, elevations in serum aminotransferase levels were common, occurring in 39% to 45% of patients, and were greater than 5 times the upper limit of normal (ULN) in 3% to 6%. In addition, there have been several reports of clinically apparent liver injury arising during regorafenib therapy which was often severe and occasionally fatal, estimated to occur in 0.3% of treated subjects. For these reasons, routine monitoring of liver enzymes is recommended. Regorafenib induced liver injury can present in several different patterns or phenotypes. Some patients present within a few days of starting regorafenib with acute hepatic necrosis, high levels of serum aminotransferase and lactic dehydrogenase with mild jaundice, but prolongation of INR and signs of hepatic failure. The injury can be severe but is generally self-limited and recovery is rapid and complete. Other patients present with an acute viral hepatitis like pattern, hepatocelllar (or mixed) serum enzyme elevations and jaundice that can be prolonged and has been fatal in several instances. Autoimmune and immunoallergic features are uncommon. In addition, rare instances of regorafenib associated liver injury have presented with a sinusoidal obstruction-like syndrome or pseudocirrhosis, with marked hepatic nodularity and ascites that eventually improves or resolves. Finally, regorafenib, like other multi-kinase inhibitors [sunitinib, imatinib, sorafenib], has also been associated with episodes of hyperammonemic coma generally arising within a few days or weeks of starting and with rapid reversal upon stopping treatment.
Likelihood score: B (highly likely cause of clinically apparent liver injury).

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Effects During Pregnancy and Lactation
◉ Summary of Use during Lactation
No information is available on the clinical use of regorafenib during breastfeeding. Because regorafenib is 99.5% bound to plasma proteins, the amount in milk is likely to be low. However, one of its metabolites has a half-life of up to 70 hours, and might accumulate in the infant. The manufacturer recommends that breastfeeding be discontinued during regorafenib therapy and for 2 weeks after the final dose.
◉ Effects in Breastfed Infants
Relevant published information was not found as of the revision date.
◉ Effects on Lactation and Breastmilk
Relevant published information was not found as of the revision date.

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Protein Binding
Regorafenib is highly bound (99.5%) to human plasma proteins.

[1]. Regorafenib (BAY 73-4506): a new oral multikinase inhibitor of angiogenic, stromal and oncogenic receptor tyrosine kinases with potent preclinical antitumor activity. Int J Cancer, 2011, 129(1), 245-255.

[2]. Fluoro-Bay 43-9006 (Regorafenib) effects on hepatoma cells: growth inhibition, quiescence, and recovery. J Cell Physiol, 2013, 228(2), 292-297.

Regorafenib is a pyridinecarboxamide obtained by condensation of 4-[4-({[4-chloro-3-(trifluoromethyl)phenyl]carbamoyl}amino)-3-fluorophenoxy]pyridine-2-carboxylic acid with methylamine. Used for for the treatment of metastatic colorectal cancer in patients who have previously received chemotherapy, anti-EGFR or anti-VEGF therapy. It has a role as an antineoplastic agent, a tyrosine kinase inhibitor and a hepatotoxic agent. It is an aromatic ether, a pyridinecarboxamide, a member of monochlorobenzenes, a member of (trifluoromethyl)benzenes, a member of monofluorobenzenes and a member of phenylureas.
Regorafenib is an orally-administered inhibitor of multiple kinases. It is used for the treatment of metastatic colorectal cancer, advanced gastrointestinal stromal tumours, and hepatocellular carcinoma. FDA approved on September 27, 2012. Approved use of Regorafenib was expanded to treat Hepatocellular Carcinoma in April 2017.
Regorafenib anhydrous is a Kinase Inhibitor. The mechanism of action of regorafenib anhydrous is as a Kinase Inhibitor, and Cytochrome P450 2C9 Inhibitor, and Breast Cancer Resistance Protein Inhibitor, and UGT1A9 Inhibitor, and UGT1A1 Inhibitor.
Regorafenib is an oral multi-kinase inhibitor that is used in the therapy of refractory metastatic colorectal cancer, hepatocellular carcinoma and gastrointestinal stromal tumor. Regorafenib has been associated with frequent serum aminotransferase elevations during therapy and with rare, but sometimes severe and even fatal instances of clinically apparent liver injury.
Regorafenib Anhydrous is the anhydrous form of regorafenib, an orally bioavailable small molecule with potential antiangiogenic and antineoplastic activities. Regorafenib binds to and inhibits vascular endothelial growth factor receptors (VEGFRs) 2 and 3, and Ret, Kit, PDGFR and Raf kinases, which may result in the inhibition of tumor angiogenesis and tumor cell proliferation. VEGFRs are receptor tyrosine kinases that play important roles in tumor angiogenesis; the receptor tyrosine kinases RET, KIT, and PDGFR, and the serine/threonine-specific Raf kinase are involved in tumor cell signaling.
Regorafenib is the hydrate form of regorafenib, an orally bioavailable small molecule with potential antiangiogenic and antineoplastic activities. Regorafenib binds to and inhibits vascular endothelial growth factor receptors (VEGFRs) 2 and 3, and Ret, Kit, PDGFR and Raf kinases, which may result in the inhibition of tumor angiogenesis and tumor cell proliferation. VEGFRs are receptor tyrosine kinases that play important roles in tumor angiogenesis; the receptor tyrosine kinases RET, KIT, and PDGFR, and the serine/threonine-specific Raf kinase are involved in tumor cell signaling.
See also: Regorafenib Monohydrate (active moiety of).

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Drug Indication
Regorafenib is indicated for the treatment of patients with metastatic colorectal cancer (CRC) who have been previously treated with fluoropyrimidine-, oxaliplatin- and irinotecan-based chemotherapy, an anti-VEGF therapy, and, if KRAS wild type, an anti-EGFR therapy. Regorafenib is also indicated for the treatment of patients with locally advanced, unresectable or metastatic gastrointestinal stromal tumour (GIST) who have been previously treated with imatinib mesylate and sunitinib malate. Regorafenib is also indicated for the treatment of patients with hepatocellular carcinoma (HCC) previously treated with sorafenib.
FDA Label
Stivarga is indicated as monotherapy for the treatment of adult patients with: metastatic colorectal cancer (CRC) who have been previously treated with, or are not considered candidates for, available therapies - these include fluoropyrimidine-based chemotherapy, an anti-VEGF therapy and an anti-EGFR therapy; unresectable or metastatic gastrointestinal stromal tumors (GIST) who progressed on or are intolerant to prior treatment with imatinib and sunitinib; hepatocellular carcinoma (HCC) who have been previously treated with sorafenib.
Treatment of all conditions contained in the category of malignant neoplasms (except haematopoietic and lymphoid tissue)

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Mechanism of Action
Regorafenib is a small molecule inhibitor of multiple membrane-bound and intracellular kinases involved in normal cellular functions and in pathologic processes such as oncogenesis, tumor angiogenesis, and maintenance of the tumor microenvironment. In in vitro biochemical or cellular assays, regorafenib or its major human active metabolites M-2 and M-5 inhibited the activity of RET, VEGFR1, VEGFR2, VEGFR3, KIT, PDGFR-alpha, PDGFR-beta, FGFR1, FGFR2, TIE2, DDR2, TrkA, Eph2A, RAF-1, BRAF, BRAFV600E , SAPK2, PTK5, and Abl at concentrations of regorafenib that have been achieved clinically. In in vivo models, regorafenib demonstrated anti-angiogenic activity in a rat tumor model, and inhibition of tumor growth as well as anti-metastatic activity in several mouse xenograft models including some for human colorectal carcinoma.

C21H15CLF4N4O3.CH4O3S

578.9211

578.065

835621-08-4

Regorafenib;755037-03-7;Regorafenib monohydrate;1019206-88-2;Regorafenib-d3;1255386-16-3

11167602

Typically exists as solid at room temperature

6.81

3

8

5

33

686

0

C1(C(NC)=O)=NC=CC(OC2=CC=C(NC(=O)NC3=CC=C(Cl)C(C(F)(F)F)=C3)C(F)=C2)=C1.S(C)(=O)(O)=O

FNHKPVJBJVTLMP-UHFFFAOYSA-N

InChI=1S/C21H15ClF4N4O3/c1-27-19(31)18-10-13(6-7-28-18)33-12-3-5-17(16(23)9-12)30-20(32)29-11-2-4-15(22)14(8-11)21(24,25)26/h2-10H,1H3,(H,27,31)(H2,29,30,32)

4-[4-[[4-chloro-3-(trifluoromethyl)phenyl]carbamoylamino]-3-fluorophenoxy]-N-methylpyridine-2-carboxamide

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)

May dissolve in DMSO (in most cases), if not, try other solvents such as H2O, Ethanol, or DMF with a minute amount of products to avoid loss of samples

Note: Listed below are some common formulations that may be used to formulate products with low water solubility (e.g. < 1 mg/mL), you may test these formulations using a minute amount of products to avoid loss of samples.

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Injection Formulation 1: DMSO : Tween 80： Saline = 10 : 5 : 85 (i.e. 100 μL DMSO stock solution → 50 μL Tween 80 → 850 μL Saline)
*Preparation of saline: Dissolve 0.9 g of sodium chloride in 100 mL ddH ₂ O to obtain a clear solution.
Injection Formulation 2: DMSO : PEG300 ：Tween 80 : Saline = 10 : 40 : 5 : 45 (i.e. 100 μL DMSO → 400 μLPEG300 → 50 μL Tween 80 → 450 μL Saline)
Injection Formulation 3: DMSO : Corn oil = 10 : 90 (i.e. 100 μL DMSO → 900 μL Corn oil)
Example: Take the Injection Formulation 3 (DMSO : Corn oil = 10 : 90) as an example, if 1 mL of 2.5 mg/mL working solution is to be prepared, you can take 100 μL 25 mg/mL DMSO stock solution and add to 900 μL corn oil, mix well to obtain a clear or suspension solution (2.5 mg/mL, ready for use in animals).

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Injection Formulation 4: DMSO : 20% SBE-β-CD in saline = 10 : 90 [i.e. 100 μL DMSO → 900 μL (20% SBE-β-CD in saline)]
*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.
Injection Formulation 5: 2-Hydroxypropyl-β-cyclodextrin : Saline = 50 : 50 (i.e. 500 μL 2-Hydroxypropyl-β-cyclodextrin → 500 μL Saline)
Injection Formulation 6: DMSO : PEG300 : castor oil : Saline = 5 : 10 : 20 : 65 (i.e. 50 μL DMSO → 100 μLPEG300 → 200 μL castor oil → 650 μL Saline)
Injection Formulation 7: Ethanol : Cremophor : Saline = 10： 10 : 80 (i.e. 100 μL Ethanol → 100 μL Cremophor → 800 μL Saline)
Injection Formulation 8: Dissolve in Cremophor/Ethanol (50 : 50), then diluted by Saline
Injection Formulation 9: EtOH : Corn oil = 10 : 90 (i.e. 100 μL EtOH → 900 μL Corn oil)
Injection Formulation 10: EtOH : PEG300：Tween 80 : Saline = 10 : 40 : 5 : 45 (i.e. 100 μL EtOH → 400 μLPEG300 → 50 μL Tween 80 → 450 μL Saline)

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Oral Formulation 1: Suspend in 0.5% CMC Na (carboxymethylcellulose sodium)
Oral Formulation 2: Suspend in 0.5% Carboxymethyl cellulose
Example: Take the Oral Formulation 1 (Suspend in 0.5% CMC Na) as an example, if 100 mL of 2.5 mg/mL working solution is to be prepared, you can first prepare 0.5% CMC Na solution by measuring 0.5 g CMC Na and dissolve it in 100 mL ddH2O to obtain a clear solution; then add 250 mg of the product to 100 mL 0.5% CMC Na solution, to make the suspension solution (2.5 mg/mL, ready for use in animals).

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Oral Formulation 3: Dissolved in PEG400
Oral Formulation 4: Suspend in 0.2% Carboxymethyl cellulose
Oral Formulation 5: Dissolve in 0.25% Tween 80 and 0.5% Carboxymethyl cellulose
Oral Formulation 6: Mixing with food powders

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Note: Please be aware that the above formulations are for reference only. InvivoChem strongly recommends customers to read literature methods/protocols carefully before determining which formulation you should use for in vivo studies, as different compounds have different solubility properties and have to be formulated differently.

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