Biricodar is a P-glycoprotein and MRP-1 modulator.

Biricodar shows activity against both P-glycoprotein (Pgp) and MRP-1. It also has activity in increasing drug uptake and retention and reversing drug resistance mediated by wild-type BCRP (BCRPR482). Biricodar also increases the uptake, retention and cytotoxicity in HL60/Adr (MRP-1) and 8226/MR20 cells (BCRP(R482)). And it has little effect in MCF7 AdVP3000 cells (BCRP(R482T))[1]. Biricodar effectively inhibits photoaffinity labeling of P-glycoprotein by [3H]azidopine or [125I]iodoaryl azido-prazosin with EC50 values of 0.75 and 0.55 μM[3]. In 8226/Dox6 cells (Pgp), biricodar increases mitoxantrone and daunorubicin uptake by 55 and 100%, respectively, increases their retention by 100 and 60%, respectively, and increases their cytotoxicity 3.1- and 6.9-fold, respectively. VX-710 is a non-macrocyclic pipecolinate derivative which binds the FK506 receptor protein and it has been shown to restore sensitivity in a range of multidrug-resistant cells, including myeloma, melanoma, carcinoma and leukaemia[2].