870281-82-6

Idelalisib (CAS 870281-82-6) is a potent (IC50 = 2.5nM) and selective (IC50’s: PI3Ka = 820nM, PI3Kb = 565nM, PI3Kg = 89nM) PI3Kd inhibitor.1,2 Useful clinical agent for the treatment of various blood cancers. Idelalisib attenuates regulatory T cells (Treg) but not conventional T cells (Tconv) resulting in a significant increase in tumor-infiltrating antigen-specific CD8 T cells in a murine lung cancer model.3 Conversely, systemic PI3Kd inactivation antagonized anti-CTLA-4 and anti-PD-L1 treatment.4 Others have found that Idelalisib minimally influenced rituximab- and obinutuzumab-mediated Ab-dependent cellular cytotoxicity in human lymphoma cells.5

CAL-101 is a PI3K/mTOR pathway inhibitor used in the treatment of myeloid leukemia through sensitizing the cells to combatting drugs. Potent PI3K-p110-delta inhibitor.

ChEBI: A member of the class of quinazolines that is 5-fluoro-3-phenylquinazolin-4-one in which the hydrogen at position 2 is replaced by a (1S)-1-(3H-purin-6-ylamino)propyl group. used for for the treatment of refractory indol nt non-Hodgkin's lymphoma and relapsed chronic lymphocytic leukemia.

1) Herman?et al. (2010), Phosphatidylinositol 2-kinase-d inhibitor CAL-101 shows promising preclinical activity in chronic lymphocytic leukemia by antagonizing intrinsic and extrinsic cellular survival signals; Blood?116 2078 2) Lannutti?et al. (2011), CAL-101, a p110d selective phosphatidylinositol-3-kinase inhibitor for the treatment of B-cell malignancies, inhibits PI3K signaling and cellular viability; Blood 117 591 3) Ahmad?et al. (2017), Differential PI3Kd Signaling in CD4+ T-cell Subsets Enables Selective Targeting of T Regulatory Cells to Enhance Cancer Immunotherapy; Cancer Res. 77 1892 4) Lim?et al. (2018), Phosphoinositide 3-kinase d inhibition promotes antitumor responses but antagonizes checkpoint inhibitors; JCI Insight 3 e120626 5) Palazzo?et al.?(2018),?The PI3Kd-Selective Inhibitor Idelalisib Minimally Interferes with Immune Effector Function Mediated by Rituximab or Obinutuzumab and Significantly Augment B Cell Depletion In Vivo; J.Immunol. 200 2304