Development of\nPotent and Selective Inhibitors of\nMethylenetetrahydrofolate Dehydrogenase 2 for Targeting Acute Myeloid\nLeukemia: SAR, Structural Insights, and Biological Characterization

Methylenetetrahydrofolate\ndehydrogenase/cyclohydrolase 2 (MTHFD2),\na pivotal mitochondrial enzyme in one-carbon metabolism, is significantly\nupregulated in various cancers but minimally expressed in normal proliferating\ncells. In contrast, MTHFD1, which performs similar functions, is predominantly\nexpressed in normal cells. Therefore, targeting MTHFD2 with selective\ninhibitors holds promise for a broader therapeutic window with reduced\ntoxicity and fewer side effects. This study identified selective 2,4-diamino-6-oxo-1,6-dihydropyrimidin-5-yl\nureido-based derivatives through systematic chemical modifications\nand SAR studies. Structural biology investigations revealed substitutions\nin the phenyl ring and tail region modulate potency and selectivity\ntoward MTHFD2. Additionally, a comprehensive cell screening platform\nrevealed acute myeloid leukemia cells with FLT3 internal tandem duplication\nmutations are particularly sensitive to these inhibitors. Furthermore,\nsynergistic effects were observed when combining potential compounds\nwith Alimta. Compound <b>16e</b> emerged as a leading candidate,\ndemonstrating superior inhibition and selectivity for MTHFD2, favorable\npharmacokinetics, and potent antitumor efficacy in MOLM-14 xenograft\nmodels.