Table 1.

Receptor tyrosine kinase inhibitory activity of selected TKI’s – cell-free kinase assay (IC₅₀).

TKI	Axitinib (nM)	Tivozanib (nM)	Sunitinib (nM)	Pazopanib (nM)
Reference	Hu-Lowe (2008)	Nakamura et al. (2006)	Chow and Eckhardt (2007)	Kumar et al. (2009)
VEGFR-1	ND	30	21	7
VEGFR-2	0.2	6.5	34	15
VEGFR-3	ND	15	3	2
PDGFR-β	1.6	49	75	215
c-Kit	1.7	78	40	48
FGFR-1	ND	530	437	80

IC₅₀, inhibitory concentration 50%; TKI, tyrosine kinase inhibitor; ND, not done.