Zosuquidar

Zosuquidar is an experimental antineoplastic drug currently under development. It has completed Phase 3 clinical trials in the United States. It inhibits P-glycoproteins. Other drugs with this mechanism include tariquidar and laniquidar. P-glycoproteins are trans-membrane proteins that pump foreign substances out of cells in an ATP dependent fashion. Cancers overexpressing P-glycoproteins are able to pump out therapeutic molecules before they are able to reach their target, effectively making the cancer multi-drug resistant. Zosuquidar inhibits P-glycoproteins, inhibiting the efflux pump and restoring sensitivity to chemotherapeutic agents.