Discovery of a Potent and Selective BCL-XL Inhibitor with in Vivo Activity.
Tao ZF, Hasvold L, Wang L, Wang X, Petros AM, Park CH, Boghaert ER, Catron ND, Chen J, Colman PM, Czabotar PE, Deshayes K, Fairbrother WJ, Flygare JA, Hymowitz SG, Jin S, Judge RA, Koehler MF, Kovar PJ, Lessene G, Mitten MJ, Ndubaku CO, Nimmer P, Purkey HE, Oleksijew A, Phillips DC, Sleebs BE, Smith BJ, Smith ML, Tahir SK, Watson KG, Xiao Y, Xue J, Zhang H, Zobel K, Rosenberg SH, Tse C, Leverson JD, Elmore SW, Souers AJ.
A-1155463, a highly potent and selective BCL-XL inhibitor, was discovered through nuclear magnetic resonance (NMR) fragment screening and structure-based design. This compound is substantially more potent against BCL-XL-dependent cell lines relative to our recently reported inhibitor, WEHI-539, while possessing none of its inherent pharmaceutical liabilities. A-1155463 caused a mechanism-based and reversible thrombocytopenia in mice and inhibited H146 small cell lung cancer xenograft tumor growth in vivo following multiple doses. A-1155463 thus represents an excellent tool molecule for studying BCL-XL biology as well as a productive lead structure for further optimization.