In vitro study | IPI-549 and PI3Kγ can bind tightly with a Kd value of 290 pM, and the affinity for other I-type PI3K subtypes is more than 58 times weaker. In experiments on 48 mutant and non-mutant protein kinases and lipid kinases, IPI-549 at a concentration of 1 μm had no significant inhibitory effect on them. IPI-549 effectively inhibited PI3Kγ(IC50 = 1.2 nM) in PI3K-α, -β, -γ, and-δ-dependent intracellular p-AKT experiments, it is more than 146 times selective for other class I subtypes. In addition, IPI-549 inhibited the migration of PI3Kγ-dependent bone marrow-derived cells in vitro. Among the 80 GPCRs, ion channels, and transporters, IPI-549 at a concentration of 10 μm has high selectivity. It has moderate cell permeability and can penetrate through Caco-2x single cell layers. In hepatocytes, metabolism is slow (t1/2 > 360 min). The IC50 for the CYP subtypes tested (1A2, 2B6, 2C8, 2C9, 2C19, 2D6, 3A4) was greater than 20 μm. |
In vivo study | In in vivo models (mouse, rat, canine, and monkey),IPI-549 has good oral bioavailability, low clearance, and an average volume of distribution in tissues of 1.2 L/kg. It has good pharmacokinetic characteristics in vivo and can effectively and selectively inhibit PI3Kγ. Oral administration of IPI549 significantly and dose-dependently reduced neutrophil migration in a mouse model. In addition, in a mouse homologous model, IPI-549 inhibited tumor growth by altering immune cells in the tumor microenvironment. |