Benzoxazepin compounds of Formula I, including stereoisomers, geometric isomers, tautomers, solvates, metabolites and pharmaceutically acceptable salts thereof, wherein: Z1 is CR1 or N; Z2 is CR2 or N; Z3 is CR3 or N; Z4 is CR4 or N; and B is a pyrazolyl, imidazolyl, or triazolyl ring fused to the benzoxepin ring, are useful for inhibiting lipid kinases including p110 alpha and other isoforms of PI3K, and for treating disorders such as cancer mediated by lipid kinases. Methods of using compounds of Formula I for in vitro, in situ, and in vivo diagnosis, prevention or treatment of such disorders in mammalian cells, or associated pathological conditions, are disclosed.