Masitinib

Biological Activity

Masitinib (AB1010) is a tyrosine kinase inhibitor targeting stem cell factor receptor (c-kit) and platelet-derived growth factor (PDGF) receptor. It can enhance the antiproliferative effects of gemcitabine (GEM) in human pancreatic cancer cells. It potently inhibited human and murine KIT with activating mutations in the juxtamembrane domain. In vivo, masitinib (AB1010) blocked tumour growth in mice with subcutaneous grafts of Ba/F3 cells expressing a juxtamembrane KIT mutant. Masitinib, a c-kit and PDGF-receptor tyrosine kinase inhibitor, may represent an innovative avenue of treatment in corticosteroid-dependent asthma.

Product Citations

• 

  bioRxiv. 2021 May 23;445261.

  Non-coding NFKBIZ 3′ UTR mutations promote cell growth and resistance to targeted therapeutics in diffuse large B-cell lymphoma
  Masitinib purchased from AbMole

• 

  Blood. 2018 May 24;131(21):2345-2356.

  Pan-SRC kinase inhibition blocks B-cell receptor oncogenic signaling in non-Hodgkin lymphoma.
  Masitinib purchased from AbMole

Customer Product Validations & Biological Datas

	Source	Blood (2018). Figure 5. Masitinib (Abmole Bioscience)
	Method	BCR signaling repre
	Cell Lines	923 cells lines
	Concentrations	2.5 μM, 5 μM or 10 μM
	Incubation Time	72 h
	Results	We observed a consistent reduction of the tumor mass in animals treated with masitinib

	Source	Res Vet Sci (2014). Figure 2. Masitinib
	Method	Clonogenic assays
	Cell Lines	JB, KH and Hamilton ISS cells
	Concentrations	6 μM
	Incubation Time	24 h
	Results	There were no differences in radiosensitivity between control cells (0 lM masitinib) and those treated with 1 μM masitinib regardless of radiation dose (JB p = 0.56; KH p = 0.7; Hamilton p = 0.11); due to these comparable findings, the assay was performed only once

	Source	Res Vet Sci (2014). Figure 1. Masitinib
	Method	Clonogenic assays
	Cell Lines	JB, KH and Hamilton ISS cells
	Concentrations	6 μM
	Incubation Time	24 h
	Results	For each cell line, there were no significant differences in ISS radiosensitivity between control cells (0 μM masitinib) and those treated with 6 μM masitinib at any radiation dose (JB p = 0.11; KH p = 0.07; Hamilton p = 0.8)

Protocol

Cell Experiment
Cell lines	Ba/F3 cell
Preparation method	For the assay of Ba/F3 cell proliferation, microtitre plates were seeded with a total of 104 cells/well in 100 µl of RPMI 1640 medium with 10% foetal bovine serum at 37°C. These were supplemented, or not, with either 0.1% conditioned medium from X63-IL-3 cells or 250 ng/ml murine SCF. The murine SCF, which activates KIT, was purified from the conditioned medium of SCF-producing CHO cells (gift of S. Lyman, Immunex). Cells were grown for 48 hours at 37°C and then incubated with 10 µl/well of WST-1 reagent (Roche Applied Science, France) for 3 hours at 37°C. The amount of formazan dye formed was quantified by its absorbance at 450 nm using a scanning multiwell spectrophotometer (MultiSkan MS, Thermo-LabSystems, France). A blank well without cells was used as a background control for the spectrophotometer and all assays were performed in triplicate.
Concentrations	0~10 μM
Incubation time	48 h

Animal Experiment
Animal models	Ba/F3 Δ27 tumour model in Female MBRI Nu/Nu mice
Formulation	placebo
Dosages	10, 30, or 45 mg/kg twice daily for 10 days
Administration	orally

Conversion of different model animals based on BSA (Value based on data from FDA Draft Guidelines)

Species	Mouse	Rat	Rabbit	Guinea pig	Hamster	Dog
Weight (kg)	0.02	0.15	1.8	0.4	0.08	10
Body Surface Area (m2)	0.007	0.025	0.15	0.05	0.02	0.5
Km factor	3	6	12	8	5	20

Animal A (mg/kg) = Animal B (mg/kg) multiplied by	Animal B Km
	Animal A Km

For example, to modify the dose of Compound A used for a mouse (20 mg/kg) to a dose based on the BSA for a rat, multiply 20 mg/kg by the K_m factor for a mouse and then divide by the K_m factor for a rat. This calculation results in a rat equivalent dose for Compound A of 10 mg/kg.

Chemical Information

References

[1] Klopfleisch et al. BMC Vet Res. Transcriptome and proteome analysis of tyrosine Kinase inhibitor treated canine mast cell tumour cells identifies potentially kit signaling-dependent genes.

[2] Lyles et al. Vet Comp Oncol. In vitro effects of the tyrosine kinase inhibitor, masitinib mesylate, on canine hemangiosarcoma cell lines.

[3] Lee-Fowler et al. Int Arch Allergy Immunol. The tyrosine kinase inhibitor masitinib blunts airway inflammation and improves associated lung mechanics in a feline model of chronic allergic asthma.

[4] Georgin-Lavialle et al. Eur J Haematol. Mast cell leukemia: identification of a new c-Kit mutation, dup(501-502), and response to masitinib, a c-Kit tyrosine kinase inhibitor.

[5] Lawrence et al. Vet Comp Oncol. Masitinib demonstrates anti-proliferative and pro-apoptotic activity in primary and metastatic feline injection-site sarcoma cells.

[6] Dubreuil P, et al. PLoS One. Masitinib (AB1010), a potent and selective tyrosine kinase inhibitor targeting KIT.