HDACs/EZH2-IN-1 (Compound 22a) is a dual inhibitor of HDACs and EZH2, exhibiting potent inhibitory activity, with EZH2 Y641N being suppressed by 98% at 50 nM. It selectively targets HDAC1 and HDAC6, with IC50 values of 0.23 μM and 0.07 μM, respectively. HDACs/EZH2-IN-1 effectively inhibits the proliferation of diffuse large B-cell lymphoma cells harboring EZH2 mutations and various acute myeloid leukemia cells. Additionally, this compound has the capability to induce cellular differentiation and apoptosis (Apoptosis).

HDAC1:0.23μM(IC50), EZH2 (WT):0.84nM(IC50), EZH2 (Y641N):1.36nM(IC50), HDAC11:>10μM(IC50), HDAC4:>10μM(IC50), HDAC6:0.07μM(IC50)

HDACs/EZH2-IN-1 demonstrates significant antiproliferative effects on SU-DHL-6 DLBCL cells carrying the EZH2 Y641N mutation, achieving IC50 values of 1.04 μM at 48 h and 0.17 μM at 120 h (5 μM, 48-120 h). Additionally, this compound inhibits the growth of AML cells with IC50 values of 1.39 μM (MV4-11), 2.45 μM (U937), and 1.32 μM (OCI-AML3) at concentrations ranging from 0.1 to 100 μM over 48 hours. It also elevates intracellular levels of HDAC1/2/3 substrate acetyl-histone H3 (AC-HH3) and HDAC6 substrate acetyl-α-tubulin (AC-α-tubulin) within the same dosage and timeframe. At 2 μM for 48 hours, HDACs/EZH2-IN-1 induces differentiation in MOLM13 cells, reflected by increased expression of the myeloid maturation markers CD11b and CD14 and provokes dose-dependent apoptosis at 2-4 μM. When used in conjunction with anti-AML agents (cytarabine, doxorubicin, and gilteritinib), HDACs/EZH2-IN-1 potentiates anticancer effects on MOLM13 cells at doses of 1-2 μM. Moreover, the compound exhibits good metabolic stability in human and rat plasma, with half-lives exceeding 180 minutes and 138 minutes, respectively.