PI3Kδ-IN-1 is a potent, selective, and efficacious PI3Kδ inhibitor with an IC 50 of 1.7 nM. In Vitro PI3Kδ-IN-1 (compound 52) shows >100-fold selectivity over the other PI3K isoforms. Kinome selectivity is also excellent with >660-fold selectivity over MNK1 and others in HTRF assays. Importantly, PI3Kδ-IN-1 has an improved human/rodent in vitro stability correlation and a good permeability profile. MCE has not independently confirmed the accuracy of these methods. They are for reference only. In Vivo PI3Kδ-IN-1 (2, 5 mg/kg, orally b.i.d. for 42 days) shows greater than 50% suppression of paw swelling in mice. PI3Kδ-IN-1 has an EC 50 of 10 nM at 24 h ( ED 50 of ∼1.25 mg/kg) in mice . MCE has not independently confirmed the accuracy of these methods. They are for reference only. Animal Model: Male DBA/1 mice (20−25g) Dosage: 0.5, 2, 5 mg/kg Administration: Oral b.i.d. for 42 days, Result: A dose dependent reduction of the clinical score was observed. Doses of 2 and 5 mg/kg showed greater than 50% suppression of paw swelling . Form:Solid IC50& Target:IC50: 1.7 nM (PI3Kδ)