WM-1119

WM-1119 is a highly potent and selective KAT6A inhibitor, with an IC₅₀ of 0.25 μM for KAT6A in lymphoma cells, the binding K_D values of WM-1119 with KAT6A, KAT5 and KAT7 are 2 nM, 2.2 μM, 0.5 μM , respectively^[1]. IC50 & Target: IC50: 0.25 μM (KAT6A in lymphoma cells), KD: 2 nM (KAT6A), 2.2 μM (KAT5), 0.5 μM (KAT7)^[1]. In Vitro: WM-1119 induces cell cycle exit and cellular senescence without causing DNA damage. WM-1119 is 1,100-fold and 250-fold more active against KAT6A than against KAT5 or KAT7, respectively, and so shows greater specificity for KAT6A than does WM-8014. Treatment of MEFs with WM-1119 results in cell cycle arrest in G1 and a senescence phenotype similar to that seen upon treatment with WM-8014. Notably, the activity of WM-1119 in this cell-based assay is an order of magnitude greater than WM-8014 and WM-1119 is able to induce cell cycle arrest at 1 μM. Treatment with WM-1119 inhibits the proliferation of the EMRK1184 lymphoma cells in vitro, WM-1119 (IC₅₀=0.25 μM) is ninefold more active than WM-8014 (IC₅₀=2.3 μM), as expected on the basis of reduced protein binding^[1]. In Vivo: By day 14, the cohorts that are treated four times per day with WM-1119 have arrested tumour growth, with the exception of one mouse that does not respond. Spleen weights in the WM-1119-treatment group (treated four times per day) are substantially lower than spleen weights in the vehicle-treated group. Treatment with WM-1119 three times per day leads to a significant reduction in tumour burden and spleen weight, but is not as effective as treatment four times per day. WM-1119 is well-tolerated; mice show no generalized ill effects and weight loss is not observed. The proportion and overall number of tumour cells is substantially reduced by WM-1119 treatment (four times per day)^[1].