TGR-1202 is an orally available, next generation PI3Kdelta inhibitor, inhibits PI3K activity in enzyme and cell based assays with IC50 and EC50 values of 22.2 and 24.3 nM respectively.
TGR-1202 displays a high degree of selectivity over the alpha (>1000 fold), beta (>30-50 fold), and gamma (>15-50 fold) isoforms. Additionally, TGR-1202 causes a half-maximal inhibition of human whole blood CD19 cell proliferation between 100-300 nM. Treatment of PBMC with RP5264 resulted initially in a G2/M arrest followed by subsequent increase in the number of Sub G0 cells. Viability assays demonstrated that TGR-1202 caused a significant inhibition in growth as well as Akt phosphorylation of immortalized and primary leukemic cells. Further, the compound exhibited good oral absorption with favourable pharmacokinetic properties in rodents.