KDOAM-25 trihydrochloride is a potent and highly selective histone lysine demethylases 5 ( KDM5 ) inhibitor with IC 50 s of 71 nM, 19 nM, 69 nM, 69 nM for KDM5A, KDM5B, KDM5C, KDM5D, respectively. KDOAM-25 trihydrochloride increases global H3K4 methylation at transcriptional start sites and impairs proliferation in multiple myeloma MM1S cells.