MK-0159 (compound 37) is an orally active, potent and selective CD38 inhibitor, with IC 50 values of 22, 3, and 70 nM for human, mouse and rat CD38 , respectively. MK-0159 also shows good microsomal stability for human and rodent liver microsomes. MK-0159 increases NAD + (nicotinamide adenine dinucleotide) and reduces ADPR (adenosine diphosphate ribose) in whole blood and heart