Tuspetinib (HM43239) has activity against the sidewall FLT3 form with IC50s of 1.1 nM (FLT3 wild type), 1.8 nM (FLT3 ITD mutant) and 1.0 nM (FLT3 D835Y mutant). Tuspetinib works as a reversible type I dye that directly inhibits FLT3 apoptosis and modulates p-STAT5, p-ERK SYK, JAK1/2, and TAK1. Tuspetinib inhibits apoptosis and causes apoptosis (apoptosis) of cells.

Physicochemical Properties

Molecular Formula	C29H33CLN6
Molecular Weight	501.0655
Exact Mass	500.245
CAS #	2294874-49-8
PubChem CID	135390910
Appearance	White to off-white solid powder
LogP	5.8
Hydrogen Bond Donor Count	3
Hydrogen Bond Acceptor Count	5
Rotatable Bond Count	6
Heavy Atom Count	36
Complexity	725
Defined Atom Stereocenter Count	2
SMILES	ClC1=C([H])N=C(N=C1C1=C([H])N([H])C2C([H])=C(C([H])([H])[H])C([H])=C([H])C1=2)N([H])C1=C([H])C(C([H])([H])N2C([H])([H])[C@@]([H])(C([H])([H])[H])N([H])[C@@]([H])(C([H])([H])[H])C2([H])[H])=C([H])C(=C1[H])C1([H])C([H])([H])C1([H])[H]
InChi Key	FZLSDZZNPXXBBB-KDURUIRLSA-N
InChi Code	InChI=1S/C29H33ClN6/c1-17-4-7-24-25(12-31-27(24)8-17)28-26(30)13-32-29(35-28)34-23-10-20(9-22(11-23)21-5-6-21)16-36-14-18(2)33-19(3)15-36/h4,7-13,18-19,21,31,33H,5-6,14-16H2,1-3H3,(H,32,34,35)/t18-,19+
Chemical Name	5-chloro-N-[3-cyclopropyl-5-[[(3S,5R)-3,5-dimethylpiperazin-1-yl]methyl]phenyl]-4-(6-methyl-1H-indol-3-yl)pyrimidin-2-amine
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 Note: This product requires protection from light (avoid light exposure) during transportation and storage.
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	Acute myeloid leukemia cell lines with FLT3 ITD mutations, such as MV4-11 (IC50: 1.3 nM), MOLM-13 (IC50: 5.1 nM), and MOLM-14 (IC50: 2.9 nM), are potently inhibited by tuspetinib in their proliferation. Tuspetinib causes the carbohydrate stem cell (LSC) marker KG1a cells to enlarge, and caspase 3/7 prevents KG1a cells (CD34+/CD38- cells) from proliferating [1]. In KG1a cells, tuspetinib can efficiently prevent SYK, STAT3, and STAT5 phosphorylation [3].
ln Vivo	Tuspetinib showed good dose-proportional anti-tumor efficacy in mice models xenografted with MV4-11 and MOLM-13 cell lines without any major toxicity [1]. Tuspetinib can prolong the survival of FLT3 ITD/TKD double mutant xenograft mice [3].
References	[1]. Miyoung Lee, et.al. Abstract 804: Antitumor activity of the potent and novel FLT3 inhibitor HM43239 in acute myeloid leukemia. Cancer Res July 1 2018 (78) (13 Supplement) 804. [2]. Naval G. Daver, et.al. HM43239, a Novel Potent Small Molecule FLT3 Inhibitor, in Acute Myeloid Leukemia (AML) with FMS-like Tyrosine Kinase 3 (FLT3) Mutations: Phase 1 /2 Study. Blood 2019; 134 (Supplement_1): 1331. [3]. JiSook Kim, et.al. Abstract 1293: HM43239, a novel FLT3 inhibitor in overcoming resistance for acute myeloid leukemia. Cancer Res July 1 2019 (79) (13 Supplement) 1293.
Additional Infomation	Tuspetinib (HM-43239) is under investigation in clinical trial NCT03850574 (Clinical Trial to Evaluate the Safety, Tolerability, Pharmacokinetics and Pharmacodynamics of HM43239 in Patients With Relapsed or Refractory Acute Myeloid Leukemia). Tuspetinib is a selective, reversible type I inhibitor of FMS-like tyrosine kinase 3 (FLT3; CD135; STK1; FLK2) with potential antineoplastic activity. Upon administration, tuspetinib reversibly binds to and inhibits the activity of FLT3. This inhibits the proliferation of FLT3-expressing cancer cells. FLT3, a class III receptor tyrosine kinase (RTK), is overexpressed or mutated in most B-lineage neoplasms and in acute myeloid leukemias.

Solubility Data

Solubility (In Vitro)

DMSO : ~125 mg/mL (~249.47 mM)

Solubility (In Vivo)

Solubility in Formulation 1: ≥ 2.08 mg/mL (4.15 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 20.8 mg/mL clear DMSO stock solution to 900 μL of corn oil and mix evenly.  (Please use freshly prepared in vivo formulations for optimal results.)

Preparing Stock Solutions		1 mg	5 mg	10 mg
	1 mM	1.9957 mL	9.9786 mL	19.9573 mL
	5 mM	0.3991 mL	1.9957 mL	3.9915 mL
	10 mM	0.1996 mL	0.9979 mL	1.9957 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.