•Novel
proprietary small molecules that act as polyamine transport inhibitors (PTIs)
or polyamine-drug conjugates (transport-based poisons)
•These
two strategies exploit the highly upregulated polyamine transport system in
cancer, either by direct blockade or as a 'Trojan Horse' attack
•In
preclinical studies, these strategies safely and effectively debulk
tumors
•Mechanistic
studies show that the therapies work chiefly by eradicating myeloid-derived
suppressor cells that mediate immunosuppression
•Preclinical
studies have demonstrated general anti-tumor efficacy in multiple experimental
tumor systems, including melanoma, breast, ovarian, colorectal and pancreatic
cancers
•General
utility to safely heighten the anti-cancer efficacy of combination
chemotherapy, molecular targeted therapy and immunotherapy