tariquidar + vinorelbine

Tariquidar + vinorelbine is a combination of two small molecule drugs investigated primarily for overcoming multidrug resistance in cancer therapy. Tariquidar is a third-generation anthranilic acid derivative that acts as a potent and selective inhibitor of P-glycoprotein (P-gp, also known as ABCB1), an efflux transporter responsible for mediating multidrug resistance by pumping chemotherapeutic agents out of cancer cells[5][2]. By inhibiting P-gp, tariquidar increases the intracellular concentration and efficacy of co-administered cytotoxic drugs. Vinorelbine is a semi-synthetic vinca alkaloid classified as a spindle poison; it inhibits mitosis by binding to tubulin and disrupting microtubule assembly, thereby arresting cell division in proliferating tumor cells[6][4]. The combination has been studied in phase I clinical trials to determine safety, pharmacokinetics, and maximum tolerated dose in patients with advanced cancers[1][2]. Tariquidar had no significant effect on the pharmacokinetics of vinorelbine or vice versa but increased retention of imaging tracers consistent with P-gp inhibition. The main toxicity observed was neutropenia related to vinorelbine dosing.