ORY-1001 is an inhibitor of lysine-specific demethylase 1 (LSD1), an oxidase that demethylates histone 3 at lysine 4 (H3K4) and H3K9 (IC = 0.018 µM). It is selective for LSD1 over LSD2, monoamine oxidase A (MAO-A), and MAO-B (ICs = >100 µM) but does inhibit spermine oxidase (IC = 7.4 µM). ORY-1001 also inhibits the imidazoline I receptor, norepinephrine and dopamine transporters, and L-type voltage-gated calcium channels (ICs = 0.37, 2.4, 1.7, and 4.9 µM, respectively). It induces accumulation of dimethylated H3K4 (H3K4me2) in THP-1 cells (EC = 0.0022 µM) and reduces viability in a panel of primary acute myeloid leukemia (AML) cells when used at a concentration of 100 nM. ORY-1001 (0.0125 mg/kg) increases survival in a patient-derived xenograft (PDX) mouse model of T cell acute lymphoblastic leukemia (T-ALL). Formulations containing ORY-1001 have been used in the treatment of AML.