KDM5A-IN-1 is a potent, orally bioavailable pan-histone lysine demethylases 5 (KDM5) inhibitor with IC50s of 45 nM, 56 nM and 55 nM for KDM5A, KDM5B and KDM5C, respectively, and with an EC50 value of 960 nM for PC9 H3K4Me3. KDM5A-IN-1 is significantly less potent against other KDM5B enzymes (1A, 2B, 3B, 4C, 6A, 7B).