Menin-KMT2A protein-protein interaction

Class

Small molecule menin inhibitor

Pathway

KMT2A(MLL)-rearranged / NPM1-mutant HOX/MEIS1 transcriptional program

Menin is a scaffold protein that normally helps organize gene-regulatory complexes in the nucleus. In certain aggressive leukemias, menin partners abnormally with KMT2A (also called MLL), either because KMT2A has been altered by a chromosomal rearrangement or because a separate mutation in the gene NPM1 leads leukemic cells to depend on the same partnership. This menin-KMT2A interaction sustains a set of genes, including HOXA9 and MEIS1, that keep immature blood-forming cells locked in a self-renewing, non-differentiating state characteristic of leukemia. Rather than blocking an enzyme's chemical activity, drugs in this class occupy the pocket on menin where KMT2A normally docks, physically breaking the interaction. This removes menin and its bound partners from the relevant genes, allowing the HOX/MEIS1 program to shut off, prompting the leukemic cells to differentiate and lose their proliferative advantage. Because this dependency spans both KMT2A-rearranged leukemias and NPM1-mutant leukemias, disrupting one protein-protein interaction addresses two molecularly distinct but functionally convergent disease subsets. This approach broadly matters in acute leukemias where a differentiation block, rather than uncontrolled proliferation alone, drives disease persistence, offering a route to therapy that targets the transcriptional machinery underlying that block rather than a downstream kinase or metabolic pathway.