Idelalisib (b)

Idelalisib is a selective inhibitor of p110δ (IC50 : 2.5 nM; in cell-free assays) ; shown to have 40- to 300-fold greater selectivity for p110δ than p110α/β/γ, and 400- to 4000-fold more selectivity to p110δ than C2β, hVPS34, DNA-PK and mTOR.CAL-101 blocked constitutive phosphatidylinositol-3-kinase signaling, resulting in decreased phosphorylation of Akt and other downstream effectors, an increase in poly (ADP-ribose) polymerase and caspase cleavage and an induction of apoptosis.