Rebastinib (formerly also known as DCC-2036), a novel, potent and orally bioavailable small-molecule inhibitor of multiple tyrosine kinases with potential antineoplastic activity, is a conformational control Bcr-Abl inhibitor for Abl1(WT) and Abl1(T315I) with IC50s of 0.8 nM and 4 nM. It also inhibits other kinases such as SRC, LYN, FGR, HCK, KDR, FLT3, and Tie-2, and has low activity towards c-Kit. DCC-2036 inhibits ABL1 through forcing the kinase domains into inhibitor-bound, inactive Type II conformations. In cellular assay, DCC-2036 inhibits the proliferation of Ba/F3 and K562 cells with IC50 values of 5.4nM and 5.5nM, respectively.

Physicochemical Properties

Molecular Formula	C30H28FN7O3
Molecular Weight	553.59
Exact Mass	553.223
CAS #	1020172-07-9
Related CAS #	1020172-07-9
PubChem CID	25066467
Appearance	White to off-white solid powder
Density	1.3±0.1 g/cm3
Boiling Point	666.8±55.0 °C at 760 mmHg
Flash Point	357.0±31.5 °C
Vapour Pressure	0.0±2.0 mmHg at 25°C
Index of Refraction	1.655
LogP	4.9
Hydrogen Bond Donor Count	3
Hydrogen Bond Acceptor Count	7
Rotatable Bond Count	7
Heavy Atom Count	41
Complexity	904
Defined Atom Stereocenter Count	0
InChi Key	WVXNSAVVKYZVOE-UHFFFAOYSA-N
InChi Code	InChI=1S/C30H28FN7O3/c1-30(2,3)26-17-27(38(37-26)19-7-9-23-18(14-19)6-5-12-33-23)36-29(40)35-24-10-8-20(15-22(24)31)41-21-11-13-34-25(16-21)28(39)32-4/h5-17H,1-4H3,(H,32,39)(H2,35,36,40)
Chemical Name	N-[3-tert-Butyl-1-(quinolin-6-yl)-1H-pyrazol-5-yl]-N'-[2-fluoro-4-[(2-(methylcarbamoyl)pyridin-4-yl)oxy]phenyl]urea
Synonyms	DCC-2036; DCC 2036; DCC2036; Rebastinib.
HS Tariff Code	2934.99.9001
Storage	Powder-20°C 3 years 4°C 2 years In solvent -80°C 6 months -20°C 1 month
Shipping Condition	Room temperature (This product is stable at ambient temperature for a few days during ordinary shipping and time spent in Customs)

Biological Activity

ln Vitro	It is believed that u-ABL1native (IC50 0.82 nM) mostly exists in the inactive type II conformation, and rebastinib potently inhibits it. Furthermore, p-ABL1native (IC50 2 nM) is significantly inhibited by ribatinib, leading to a higher likelihood of the protein adopting the active form I mutant [1]. Given that the T315I mutation stabilizes the activated hydrophobic spine, u-ABL1T315I (IC50 5 nM) and p-ABL1T315I (IC50 4 nM) primarily occur in the I-type conformation and are efficiently inhibited by ribazinib [1]. Furthermore, ribatinib inhibits PDGFRα and PDGFRβ, as well as the SRC family kinases LYN, SRC, FGR, and HCK, with IC50 values of 29±1, 34±6, 38±1, 40±1, 70±10, and 113 nM, respectively, in addition to ABL1. Noticeably, c-KIT (IC50 481 nM) was unaffected by ribatinib [1]. When Ba/F3 cells express natural BCR-ABL1, rebastinib substantially inhibits their growth (IC50 5.4 nM). Furthermore, the Ph+ cell line K562 (IC50 5.5 nM) is not able to proliferate when treated with rebastinib]1. Additionally, with an IC50 ranging from 6-150 nM, rebastinib inhibits the proliferation of several common TKI-resistant mutations of BCR-ABL1, including G250E, Q252H, Y235F, E255K, V299L, F317L, and M351T. Resistant to autophosphorylation, rebastinib potently suppresses the phosphorylation of STAT5 in both cell lines (IC50 28 nM and 13 nM, respectively), as well as BCR-ABL1native (IC50 29 nM) and BCR-ABL1T315I (IC50 18 nM) [1].
ln Vivo	Rebastinib (DCC-2036; oral; 100 mg/kg) can effectively block BCR-ABL1 signaling in Ba/F3-BCR-ABL1T315I leukemia cells isolated from BM and spleen of tumor-bearing mice for up to 8 hours, and a single dose can result in circulating plasma levels that surpass 12 μM for up to 24 hours[1]. Rebastinib at 100 mg/kg once daily by oral gavage dramatically increased the survival of mice harboring Ba/F3-BCR-ABL1T315I leukemia cells, although STI571 at 100 mg/kg twice daily is ineffective[1]. Rebastinib lowers the leukemia cell burden in the spleens of treated mice and is equally effective in treating BCR-ABLT315I leukemia in this aggressive allograft model as STI571 at 100 mg/kg twice day in BCR-ABL1native leukemia[1].
Animal Protocol	Dissolved in 0.5% CMC/1% Tween-80; ≤100 mg/kg; p.o. Ba/F3 cells transformed to interleukin-3 independence by transduction with either Bcr-Abl1native or Bcr-Abl1T315I retrovirus are injected intravenously into syngeneic Balb/c mice.
References	[1]. Conformational control inhibition of the BCR-ABL1 tyrosine kinase, including the gatekeeper T315I mutant, by the switch-control inhibitor DCC-2036. Cancer Cell. 2011, 19(4), 556-568.
Additional Infomation	DCC-2036 is a member of the class of ureas that is urea in which one of the nitrogens bears a 3-tert-butyl-1-(quinolin-6-yl)-1H-pyrazol-5-yl substituent, while the other bears a 2-fluoro-4-{[2-(methylcarbamoyl)pyridin-4-yl]oxy}phenyl substituent. It has a role as a tyrosine kinase inhibitor. It is a member of quinolines, a pyridinecarboxamide, a member of pyrazoles, an organofluorine compound and a member of phenylureas. Rebastinib has been used in trials studying the treatment of Chronic Myeloid Leukemia. It is an inhibitor of Tie2 tyrosine kinase receptor and an antineoplastic agent. Rebastinib is an orally bioavailable small-molecule inhibitor of multiple tyrosine kinases with potential antineoplastic activity. Upon oral administration, rebastinib binds to and inhibits the Bcr-Abl fusion oncoprotein by changing the conformation of the folded protein to disallow ligand-dependent and ligand-independent activation; in addition, this agent binds to and inhibits Src family kinases LYN, HCK and FGR and the receptor tyrosine kinases TIE-2 and VEGFR-2. Rebastinib may exhibit more potent activity against T315I Bcr-Abl gatekeeper mutant kinases than other Bcr-Abl kinase inhibitors. The TIE-2 and VEGFR-2 receptor tyrosine kinases regulate angiogenesis, respectively, while the Src family kinases Abl, LYN, and HCK Src regulate a variety of cellular responses including differentiation, division, adhesion, and the stress response. See also: Rebastinib Tosylate (annotation moved to).

Solubility Data

Solubility (In Vitro)

DMSO: 111 mg/mL (200.5 mM) Water:<1 mg/mL Ethanol: 16 mg/mL (28.9 mM)

Solubility (In Vivo)

Solubility in Formulation 1: ≥ 2.08 mg/mL (3.76 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 20.8 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. Solubility in Formulation 2: ≥ 2.08 mg/mL (3.76 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 20.8 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. Solubility in Formulation 3: 0.5% CMC+0.25% Tween 80:16 mg/mL  (Please use freshly prepared in vivo formulations for optimal results.)

Preparing Stock Solutions		1 mg	5 mg	10 mg
	1 mM	1.8064 mL	9.0320 mL	18.0639 mL
	5 mM	0.3613 mL	1.8064 mL	3.6128 mL
	10 mM	0.1806 mL	0.9032 mL	1.8064 mL

*Note: Please select an appropriate solvent for the preparation of stock solution based on your experiment needs. For most products, DMSO can be used for preparing stock solutions (e.g. 5 mM, 10 mM, or 20 mM concentration); some products with high aqueous solubility may be dissolved in water directly. Solubility information is available at the above Solubility Data section. Once the stock solution is prepared, aliquot it to routine usage volumes and store at -20°C or -80°C. Avoid repeated freeze and thaw cycles.