AS 041164 is a potent inhibitor of PI 3-kinase with selectivity for the class IB isoform PI3Kγ (IC50 = 70 nM), compared to PI3Kα (IC50 = 240 nM), PI3Kβ (IC50 = 1.45 μM), and PI3Kδ (IC50 =1.70 μM). When tested at 1.0 μM, it shows little or no activity against 38 other common kinases. When given orally to mice, AS 041164 shows a pharmacokinetic profile that is similar to the general PI 3-kinase inhibitor LY294002 but is three times more potent (ED50 = 27.4 mg/kg for AS 041164 versus 81.6 mg/kg for LY294002) in blocking neutrophil recruitment induced by RANTES.