A phosphoinositide 3-kinase (PI3K) inhibitor with potential antineoplastic activity. PI3K inhibitor GSK1059615 inhibits PI3K in the PI3K/AKT kinase signaling pathway, which may trigger the translocation of cytosolic Bax to the mitochondrial outer membrane and an increase in mitochondrial membrane permeability, followed by apoptosis. Bax is a member of the proapoptotic Bcl-2 family of proteins. PIK3, an enzyme often overexpressed in cancer cells, plays a crucial role in tumor cell regulation and survival.