VU0661013 is an effective and selective inhibitor of MCL-1.

VU0661013 does not obviously suppress BCL-xL (Ki>40 μM) or BCL-2 (Ki=0.73 μM). VU0661013 shows a Ki of 97±30 pM to human MCL-1 in a TR-FRET assay by displacing a fluorescently labeled peptide derived from the pro-apoptotic protein BAK [1].

VU0661013 is a potent and selective MCL-1 inhibitor and is active in Venetoclax-resistant cells and patient-derived xenografts. VU0661013 treatment of disseminated human AML results in a dose-dependent decrease in tumor burden, nearly eliminating the hCD45+ MV-4-11 cells at the 75 mg/kg dose in the blood (mean, 13.0±2.2% in vehicle vs 7.4±7.2% in 25mg/kg vs 0.17±0.12% in 75 mg/kg treated mice), bone marrow (mean, 40.7±13.9% in vehicle vs 33.46±4.0 % in 25 mg/kg vs 0.384±0.345 in 75 mg/kg treated mice), and spleen (mean, 46.22±13.3% in vehicle vs 13.31±10.0% in 25 mg/kg vs 1.588±1.51% in 75 mg/kg treated mice). Treatment with VU0661013 reduces disease-associated splenomegaly (mean, vehicle vs. 75mg/kg, 0.17±0.02 vs 0.09±0.01g), and amending spleen to body weight ratio (vehicle vs 75mg/kg, 0.99 vs 0.50). In this study, NSGS mice are treated daily (starting 7 days after transplant) with vehicle only, 15 mg/kg or 75 mg/kg of VU0661013. Analysis reveals an increase in survival in mice treated with the 75mg/kg dose (vehicle treated mice=31 days, vs 15 mg/kg=32 days, vs 75 mg/kg treated mice=43 Days) [1].