1-[4-[5-[[2-[tert-butyl(dimethyl)silyl]oxy-2-(8-hydroxy-2-oxo-1H-quinolin-5-yl)ethyl]amino]pent-1-ynyl]phenyl]-3-[[1,6-diethyl-4-(oxan-4-ylamino)pyrazolo[3,4-b]pyridin-5-yl]methyl]urea