HM30181 is an inhibitor of P-glycoprotein (P-gp), also known as multidrug resistance protein 1 (MDR1; IC50 = 0.63 nM).1 It is selective for P-gp over breast cancer resistance protein (BCRP; IC50 = 3,700 nM), as well as multidrug resistance-associated protein 1 (MRP1), MRP2, and MRP3 at 100 ?M. It inhibits transepithelial basal-to-apical transport of paclitaxel in MDCK monolayers overexpressing P-gp (IC50 = 35.4 nM). HM30181 inhibits tumor growth and induces tumor regression in an HT-29 mouse xenograft model when administered at doses of 10 and 20 mg/kg, respectively, in combination with paclitaxel .
1.Kwak, J.-O., Lee, S.H., Lee, G.S., et al.Selective inhibition of MDR1 (ABCB1) by HM30181 increases oral bioavailability and therapeutic efficacy of paclitaxelEur. J. Pharmacol.627(1-3)92-98(2009)