KX2-391 (Tirbanibulin)

For research use only.

Catalog No.S2700 Synonyms: KX 01

30 publications

KX2-391 (Tirbanibulin) Chemical Structure

CAS No. 897016-82-9

KX2-391, the first clinical Src inhibitor (peptidomimetic class) that targets the peptide substrate site of Src, with GI50 of 9-60 nM in cancer cell lines. Phase 2.

Selleck's KX2-391 (Tirbanibulin) has been cited by 30 publications

Purity & Quality Control

Choose Selective Src Inhibitors

Biological Activity

Description KX2-391, the first clinical Src inhibitor (peptidomimetic class) that targets the peptide substrate site of Src, with GI50 of 9-60 nM in cancer cell lines. Phase 2.
Src (HuH7) [1]
(Cell-free assay)
Src (PLC/PRF/5) [1]
(Cell-free assay)
Src (Hep 3B) [1]
(Cell-free assay)
Src (Hep G2) [1]
(Cell-free assay)
9 nM(GI50) 13 nM(GI50) 26 nM(GI50) 60 nM(GI50)
In vitro

KX2-391 is a Src inhibitor that is directed to the Src substrate pocket. KX2-391 shows steep dose-response curves against Huh7 (GI 50 = 9 nM), PLC/PRF/5 (GI 50 = 13 nM), Hep3B (GI 50 = 26 nM), and HepG2 (GI 50 = 60 nM), four hepatic cell cancer (HCC) cell lines. [1] KX2-391 is found to inhibit certain leukemia cells that are resistant to current commercially available drugs, such as those derived from chronic leukemia cells with the T3151 mutation. KX2-391 is evaluated in engineered Src driven cell growth assays inNIH3T3/c-Src527F and SYF/c-Src527F cells and exhibits GI50 with 23 nM and 39 nM, respectively. [2]

Cell Data
Cell Lines Assay Type Concentration Incubation Time Formulation Activity Description PMID
mouse NIH3T3 cells NVvWXZpvTnWwY4Tpc44h[XO|YYm= M17rXFMh\GG7cx?= MWDJcohq[mm2aX;uJI9nKGOxboP0bZR2fGm4ZXz5JIFkfGm4ZTDoeY1idiClLWPSR|UzP0ZibYX0ZY51NWmwZIXj[YQh\3Kxd4ToJIlvcGmkaYTpc44hcW5ibX;1d4UhVkmKM2SzJINmdGy|IHHmeIVzKDNiZHH5d{BjgSCPVGSgZZN{[Xl? NHfE[oUzOTh3MkCyNy=>

... Click to View More Cell Line Experimental Data

Methods Test Index PMID
Western blot
α-SMA / Collagen 1 / Fibronectin / p-Src / Src ; 

PubMed: 29137389     

Cell lysates were subject to immunoblot analysis with antibodies to collagen 1, α-SMA, fibronectin, phospho-Src, Src, and GAPDH. (B) Expression levels of p-Src were quantified by densitometry and normalized with Src. 

In vivo In pre-clinical animal models of cancer, orally administered KX2-391 is shown to inhibit primary tumor growth and to suppress metastasis. [2]


Cell Research:


- Collapse
  • Cell lines: Huh7, PLC/PRF/5, Hep3B, and HepG2 cell lines
  • Concentrations: 6,564 to 0.012 nM
  • Incubation Time: 3 days
  • Method:

    Liver cell lines including Huh7, PLC/PRF/5, Hep3B, and HepG2 (NutriCyte, Buffalo, NY) are routinely cultured and maintained in basal medium containing 2% fetal bovine serum (FBS) at 37 °C and 5% CO2. Cells are seeded at 4.0 × 103/190 μL and 8.0 × 103/190 μL per well of 96-well plate in basal medium containing 1.5% FBS. These are cultured overnight at 37 °C and 5% CO2 prior to the addition of KX2-391, at concentrations ranging from 6,564 to 0.012 nM in triplicates. Treated cells are incubated for 3 days. Ten microliters of 3-(4,5-dimethylthiazol- 2-yl)-2,5-diphenyltetrazolium bromide (MTT) solution (5 mg/mL) is then added to each well on day 3 and cells incubated for 4 hours. The formazan product is dissolved with 10% SDS in dilute HCl. Optical density at 570 nm is measured by using BioTek Synergy HT multiplatform microplate reader. For comparison of activity and potency, parallel experiments are performed using KX2-391. Growth inhibition curves, 50% inhibition concentration (GI50), and 80% inhibition concentration (GI80) are determined using GraphPad Prism 5 statistical software. Data are normalized to represent percentage of maximum response as well as reported in optical density at wavelength of 570 nm (OD570) signal format.</

    (Only for Reference)

Solubility (25°C)

In vitro DMSO 86 mg/mL (199.29 mM)
Water Insoluble
Ethanol Insoluble
In vivo Add solvents to the product individually and in order(Data is from Selleck tests instead of citations):
4% DMSO+30% PEG 300+ddH2O
For best results, use promptly after mixing.

* Please note that Selleck tests the solubility of all compounds in-house, and the actual solubility may differ slightly from published values. This is normal and is due to slight batch-to-batch variations.

Chemical Information

Molecular Weight 431.53


CAS No. 897016-82-9
Storage powder
in solvent
Synonyms KX 01

In vivo Formulation Calculator (Clear solution)

Step 1: Enter information below (Recommended: An additional animal making an allowance for loss during the experiment)
Dosage mg/kg Average weight of animals g Dosing volume per animal ul Number of animals
Step 2: Enter the in vivo formulation ()
% DMSO % % Tween 80 % ddH2O

Bio Calculators

Molarity Calculator

Molarity Calculator

Calculate the mass, volume or concentration required for a solution. The Selleck molarity calculator is based on the following equation:

Mass (mg) = Concentration (mM) × Volume (mL) × Molecular Weight (g/mol)

  • Mass
    Molecular Weight

*When preparing stock solutions, please always use the batch-specific molecular weight of the product found on the via label and SDS / COA (available on product pages).

Dilution Calculator

Dilution Calculator

Calculate the dilution required to prepare a stock solution. The Selleck dilution calculator is based on the following equation:

Concentration (start) x Volume (start) = Concentration (final) x Volume (final)

This equation is commonly abbreviated as: C1V1 = C2V2 ( Input Output )

  • C1

* When preparing stock solutions always use the batch-specific molecular weight of the product found on the vial label and SDS / COA (available online).

The Serial Dilution Calculator Equation

  • Serial Dilutions

  • Computed Result

  • C1=C0/X C1: LOG(C1):
    C2=C1/X C2: LOG(C2):
    C3=C2/X C3: LOG(C3):
    C4=C3/X C4: LOG(C4):
    C5=C4/X C5: LOG(C5):
    C6=C5/X C6: LOG(C6):
    C7=C6/X C7: LOG(C7):
    C8=C7/X C8: LOG(C8):
Molecular Weight Calculator

Molecular Weight Calculator

Enter the chemical formula of a compound to calculate its molar mass and elemental composition:

Total Molecular Weight: g/mol

Tip: Chemical formula is case sensitive. C10H16N2O2 c10h16n2o2

Instructions to calculate molar mass (molecular weight) of a chemical compound:

To calculate molar mass of a chemical compound, please enter its chemical formula and click 'Calculate'.

Definitions of molecular mass, molecular weight, molar mass and molar weight:

Molecular mass (molecular weight) is the mass of one molecule of a substance and is expressed in the unified atomic mass units (u). (1 u is equal to 1/12 the mass of one atom of carbon-12)
Molar mass (molar weight) is the mass of one mole of a substance and is expressed in g/mol.

Molarity Calculator

Mass Concentration Volume Molecular Weight

Clinical Trial Information

NCT Number Recruitment interventions Conditions Sponsor/Collaborators Start Date Phases
NCT03575780 Completed Drug: KX2-391 Ointment 1% Actinic Keratoses Athenex Inc.|TKL Research Inc. September 7 2018 Phase 1
NCT02838628 Completed Drug: 50 mg of KX2-391 Ointment 1% Actinic Keratosis Almirall S.A.|Athenex Inc. April 11 2016 Phase 2
NCT02337205 Completed Drug: KX2-391 Ointment Actinic Keratosis Athenex Inc. December 2014 Phase 1
NCT01397799 Completed Drug: KX2-391 Acute Myelogenous Leukemia Kinex Pharmaceuticals Inc.|Athenex Inc. December 2013 Phase 1
NCT01074138 Completed Drug: KX2-391 Bone-Metastatic Castration-Resistant Prostate Cancer Kinex Pharmaceuticals Inc.|Athenex Inc. February 2010 Phase 2

Tech Support

Answers to questions you may have can be found in the inhibitor handling instructions. Topics include how to prepare stock solutions, how to store inhibitors, and issues that need special attention for cell-based assays and animal experiments.

Handling Instructions

Tel: +1-832-582-8158 Ext:3

If you have any other enquiries, please leave a message.

  • * Indicates a Required Field

Frequently Asked Questions

  • Question 1:

    How to formulate KX2-391 for animal trials?

  • Answer:

    KX2-391 can be dissolved in 4% DMSO/corn oil at 5 mg/ml as a homogeneous suspension for oral administration and dissolved in 4% DMSO/30% PEG 300/ddH2O at 5 mg/ml as a clear solution.

Src Signaling Pathway Map

Src Inhibitors with Unique Features

Related Src Products

Tags: buy KX2-391 (Tirbanibulin) | KX2-391 (Tirbanibulin) supplier | purchase KX2-391 (Tirbanibulin) | KX2-391 (Tirbanibulin) cost | KX2-391 (Tirbanibulin) manufacturer | order KX2-391 (Tirbanibulin) | KX2-391 (Tirbanibulin) distributor
Cell Lines Assay Type Concentration Incubation Time Formulation Activity Description PMID