– CHMFL-PI3KD-317 is a highly potent, selective, and orally active PI3Kδ inhibitor with an IC50 of 6 nM, exhibiting over 10-1500 fold selectivity over other class I, II, and III PIKK family isoforms, such as PI3Kα (IC50, 62.6 nM), PI3Kβ (IC50, 284 nM), PI3Kγ (IC50, 202.7 nM), PIK3C2A (IC50, >10000 nM), PIK3C2B (IC50, 882.3 nM), VPS34 (IC50, 1801.7 nM), PI4KIIIA (IC50, 574.1 nM), and PI4KIIIB (IC50, 300.2 nM). It inhibits PI3Kδ-mediated Akt T308 phosphorylation in Raji cells with an EC50 of 4.3 nM and has antiproliferative effects on cancer cells.