Umbralisib

Umbralisib (RP5264, TGR1202, TGR-1202) is a potent, selective, orally available PI3Kδ inhibitor with IC50 of 22 nM, 50-fold selectivity over PI3Kα/β and >10,000 fold over PI3Kγ; enhances Brentuximab Vedotin-induced Hodgkin lymphoma cell death via mitotic arrest, demonstrates highly synergistic effect with the proteasome inhibitor carfilzomib in lymphoma, leukemia, and myeloma cell lines and primary lymphoma and leukemia cells; synergistically disrupts the 4E-BP1-eIF4F-c-Myc axis with carfilzomib, also potently inhibits 60% of the activity of CK1ε at 1 uM.Blood Cancer Phase 3 Clinical (In Vitro) :Umbralisib causes a half-maximal inhibition of human whole blood CD19 cell proliferation between 100-300 nM.Umbralisib (10 nM-100 μM) inhibits phosphorylated AKT at Ser473 in a concentration-dependent manner in human lymphoma and leukemia cell lines.Umbralisib (15-50 μM) potently represses the expression of c-Myc in the DLBCL cell line LY7, and is uniquely characterized with structural features suitable for targeting CK1ε in lymphoma cells. (In Vivo) :Umbralisib (150 mg/kg, daily p.o.) significantly shrinks the tumors by day 25 in a subcutaneous xenograft model of T-cell acute lymphoblastic leukemia (T-ALL) in NOD/SCID mice using the MOLT-4 cell line.