Description
R428 is an inhibitor of Axl with IC50 of 14 nM, >100-fold selective for Axl versus Abl. Selectivty for Axl is also greater than Mer and Tyro3 (50-to-100- fold more selective) and InsR, EGFR, HER2, and PDGFRβ (100- fold more selective).
Storage
2 years -20 centigrade Powder; 2 weeks 4 centigrade in DMSO; 6 months -80 centigrade in DMSO.
Molecular Formula
C30H34N8
Chemical Name
1H-1,2,4-Triazole-3,5-diamine, 1-(6,7-dihydro-5H-benzo[6,7]cyclohepta[1,2-c]pyridazin-3-yl)-N3-[(7S)-6,7,8,9-tetrahydro-7-(1-pyrrolidinyl)-5H-benzocyclohepten-2-yl]-
Solubility
DMSO 60 mg/mL; Water <1 mg/mL; Ethanol <1 mg/mL
In vitro
R428 blocks the catalytic and procancerous activities of Axl. R428 inhibits Axl with low nanomolar activity and blocks Axl-dependent events, including Akt phosphorylation, breast cancer cell invasion, and proinflammatory cytokine production. In a recent study, the Axl inhibitor R428 shows a mean IC50 dose of ∼ 2.0μM for the primary CLL B cells after 24 hours of treatment and normal B-, T-, and natural killer (NK) cells show no significant amount of cell death at this dose of R428 (2.5 μM) under similar experimental conditions.
In vivo
Pharmacologic investigations reveal favorable exposure after oral administration such that R428-treated tumors display a dose-dependent reduction in expression of the cytokine granulocyte macrophage colony-stimulating factor and the epithelial-mesenchymal transition transcriptional regulator Snail. In support of an earlier study, R428 inhibits angiogenesis in corneal micropocket and tumor models. R428 administration reduces metastatic burden and extends survival in MDA-MB-231 intracardiac and 4T1 orthotopic (median survival, >80 days compared with 52 days; P < 0.05) mouse models of breast cancer metastasis.