Umbralisib (Synonyms: RP 5264, Umbralisib)

TGR-1202 is a PI3Kδ inhibitor, with IC50 and EC50 of 22.2 nM and 24.3 nM, respectively.

RP5264 causes a half-maximal inhibition of human whole blood CD19 cell proliferation between 100-300 nM[1]. In human lymphoma and leukemia cell lines, TGR-1202 (10 nM-100 uM) inhibits phosphorylated AKT at Ser473 in a concentration-dependent manner. TGR-1202 and carfilzomib synergistically kill blood cancer cells through disrupting the 4E-BP1-eIF4F-c-Myc axis. TGR-1202 and carfilzomib in combination synergistically and selectively silence the c-Myc and E2F transcription programs. TGR-1202 (15-50 uM) 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[2].

In a subcutaneous xenograft model of T-cell acute lymphoblastic leukemia (T-ALL) in NOD/SCID mice using the MOLT-4 cell line, TGR-1202 (150 mg/kg, daily p.o.) significantly shrinks the tumors by day 25[2].

References:
[1]. Swaroop Vakkalankaa, et al. Inhibition of PI3Kδ kinase by a selective, small molecule inhibitor suppresses B-cell proliferation and leukemic cell growth.
[2]. Deng C, et al. Silencing c-Myc translation as a therapeutic strategy through targeting PI3Kδ and CK1ε in hematological malignancies. Blood. 2017 Jan 5;129(1):88-99