Mcl-1 inhibitor 3 (compound 1) is a highly potent and orally activate macrocyclic Mcl-1 inhibitor ( K i = 0.061 nM; IC 50 =19 nM in an OPM-2 cell viability assay). Mcl-1 inhibitor 3shows good pharmacokinetic properties and excellent in vivo efficacy without toxicity..