Definition

An orally available selective inhibitor of the alpha and delta isoforms of phosphatidylinositol 3-kinase (PI3-kinase subunit alpha/delta; PI3K-alpha/delta; PI3Kalpha/delta), with potential antineoplastic activity. Upon oral administration, PI3K alpha/delta inhibitor TQ-B3525 selectively targets, binds to, and inhibits PI3K alpha and delta and prevents the activation of the PI3K/AKT signaling pathway. This decreases proliferation of and induces cell death in PI3K-alpha/delta over-expressing tumor cells. PI3K-alpha/delta also plays a key role in the B-cell receptor (BCR) signaling pathway and the proliferation of certain hematologic cancer cells. The targeted inhibition of PI3K-alpha/delta is designed to preserve PI3K signaling in normal, non-neoplastic cells, thereby minimizing serious side effects.