BYL719 is an inhibitor of phosphoinositide 3-kinase α (PI3Kα; IC
50s = 4.6, 4, and 4.8 nM for wild-type, E545K mutant, and H1047R mutant PI3K, respectively).
1 It is selective for PI3Kα over PI3Kβ, PI3Kδ, PI3Kγ, and PI4Kβ (IC
50s = 1,156, 290, 250, and 581 nM, respectively), as well as VPS34, mTOR, DNA-PK, and ATR (IC
50s = >9,100 nM for all). BYL719 (12.5, 25, and 50 mg/kg) reduces tumor volume in a PI3Kα-dependent Rat1-myr-p110α mouse xenograft model. It also reduces tumor burden in THP-1 acute myeloid leukemia (AML) and MCF-7 breast cancer mouse xenograft models.
2,3 Formulations containing BYL719 have been used in the treatment of advanced or metastatic breast cancer.