FM04 is an orally active and highly potent inhibitor of P-glycoprotein (P-gp) with an EC50 value of 83 nM. FM04 can interact with Q1193 and I1115 in human P-gp nucleotide binding domain 2 (NBD2). Thereby disrupting the R262-Q1081-Q1118 interaction pocket and uncoupling the ICL2-NBD2 interaction, thereby inhibiting P-gp. FM04 can be used in the treatment of cancer and tumors.

P-gp:83 nM(EC50)

FM04 (100 μM) exhibits competition with its photoaffinity derivative XC4 in LCC6MDR cells.[1]
FM04 inhibits P-glycoprotein with an EC50=83 nM, where the EC50 value refers to the effective modulator concentration IC50 (=3.8 nM) that reduces paclitaxel (PTX) by half in the P-gp overexpressing cell line LCC6MDR.[1]