CPI-613 is a novel anti-tumor compound presumably with a mechanism of action that does not belong to any existing pharmacological class of anti-cancer agents currently used in the clinics.Specifically,CPI-613 is referred to as an Altered Energy Metabolism-Directed (AEMD) compound,and it is selective against tumor cells (but not normal cells) according to preclinical studies.The anti-tumor effects of CPI-613 are believed to be exerted on the tumor-specific pyruvate dehydrogenase complex (PDC).Published literature indicates that umor-specific PDC is an enzyme engaged in the production of acetoin,a process that is believed to be unique in tumor cells,but not in normal cells.Consistent with the proposed mechanism is the fact that CPI-613 has been shown to have anti-tumor activity in cell culture and animal tumor models against diverse cancers independent of multiple drug resistance,cell cycle phase and signal transduction pathways.The novelty in the presumed mechanism of action for CPI-613 is further supported by the results from an ex vivo study demonstrating that CPI-613 is effective against various types of tumor cells excised from patients that displayed varying levels of resistance to different anti-cancer drugs currently used in the clinics.Some preclinical studies and interim clinical results will be discussed.