Potent and selective PI 3-kinase δ inhibitor (biochemical IC50 values are 9, 262, 1650 and 4630 nM for PI 3-Kδ, PI 3-Kα, PI 3-Kβ and PI 3-Kγ, respectively; cellular IC50 values are 49, 3440 and 6530 nM for PI 3-Kδ, PI 3-Kα and PI 3-Kβ, respectively). Selective for PI 3-Kδ over a panel of lipid and protein kinases. Inhibits B-cell function. Exhibits moderate oral bioavailability in vivo. Purity 98%. MW (observed): 492.53