MPC-9528

MPC-9528 is a small molecule inhibitor of nicotinamide phosphoribosyltransferase (Nampt), the rate-limiting enzyme in the salvage pathway of nicotinamide adenine dinucleotide (NAD) biosynthesis. Developed by Myrexis, the compound is designed to exploit the metabolic vulnerability of cancer cells that lack nicotinic acid phosphoribosyltransferase (Naprt), an enzyme required for an alternative NAD synthesis pathway. By depleting intracellular NAD levels, MPC-9528 induces cell death in Naprt-deficient tumors. To enhance the therapeutic index, it has been studied in combination with nicotinic acid (NA), which allows normal Naprt-proficient tissues to maintain NAD levels and resist toxicity, while Naprt-deficient tumor cells remain susceptible to the inhibitor.