ZSTK474 is a potent inhibitor of all four isoforms of class I PI 3-kinase (?± 6.7 nM ?2 10.4 nM ?3 11.7 nM ?′ 1.8 nM). It binds to the ATP-binding pocket and is more active and less toxic than LY294002. ZSTK474 shows anti-tumor activity against human xenografts (A549 PC-3 WiDr) in mice by arresting cell growth. In addition it was able to inhibit osteoclast formation and collagen-induced arthritis in a mouse model.
