NAD Metabolism in Acute Myeloid Leukaemia: Biological Rationale and Therapeutic Opportunities.

Acute myeloid leukaemia (AML) exhibits profound metabolic plasticity that enables leukaemic cells to survive environmental stress, nutrient limitation, and therapeutic pressure, ultimately driving disease persistence and relapse. While genetic and epigenetic alterations have guided risk stratification and therapeutic development, accumulating evidence indicates that nutrient-dependent metabolic rewiring represents a critical and targetable vulnerability in AML. Nicotinamide adenine dinucleotide (NAD) is a central metabolic cofactor whose intracellular availability is tightly linked to dietary intake of its precursors, including tryptophan, niacin (vitamin B3), nicotinamide, and nicotinamide riboside. NAD supports redox balance, mitochondrial metabolism, DNA repair, and stress adaptation, processes that are particularly critical for leukaemic stem cell survival under therapeutic stress. Recent studies demonstrate that AML cells, including those resistant to venetoclax- and hypomethylating agent-based regimens, exhibit heightened dependence on the NAD salvage pathway mediated by nicotinamide phosphoribosyltransferase (NAMPT). Pharmacological inhibition of this pathway induces profound NAD depletion, mitochondrial dysfunction(definition), and selective leukaemic cell death. In this review, we integrate nutritional biology with emerging translational evidence to examine NAD metabolism as a nutrient-regulated metabolic vulnerability in AML. We discuss dietary sources and systemic regulation of NAD, the role of NAD-dependent pathways in leukaemic persistence, the translational exploitation of NAD salvage dependency, and the emerging controversy surrounding NAD supplementation in cancer. Finally, we highlight key knowledge gaps and future directions at the interface of nutrition, metabolism, and therapy response in AML.