CH5132799 inhibits class I PI3Ks, particularly PI3Kα with IC50 of 14 nM; less potent to PI3Kβδγ, while sensitive in PIK3CA mutations cell lines. Phase 1.
CH5132799 selectively inhibits class I PI3Ks, PI3Kα (IC50 = 0.014 μM ), PI3Kβ (IC50 = 0.12 μM ), PI3Kδ (IC50 = 0.50 μM ), PI3Kγ (IC50 = 0.036 μM ), but shows less inhibition of class II PI3Ks, class III PI3k and mTOR and also no inhibitory activity (IC50 > 10 μM) against 26 protein kinases. CH5132799 exhibits more inhibitory activities against PI3Kα with oncogenic mutations E542K (IC50 = 6.7 nM), E545K (IC50 = 6.7 nM) and H1047R (IC50 = 5.6 nM) than wild-type PI3Kα. CH5132799 treated breast cnacer KPL-4 cells, which harbor the PIK3CA mutation, phosphorylation of Akt and its direct substrates, PRAS40 and FoxO1/3a and phosphorylation of downstream factors, including S6K, S6 and 4E-BP1, are effectively suppressed. Cancer cell lines harboring PIK3CA mutations are significantly sensitive to CH5132799 [1] In human tumor cell lines with PI3K pathway activation by mutation, CH5132799 shows potent antiproliferative activity [HCT116(CRC): IC50 = 0.20 lM, KPL-4(BC):13 IC50 = 0.032 lM, T-47D(BC): IC50 = 0.056 lM, SK-OV-3(Ovarian): IC50 = 0.12 lM]. CH5132799 effectively suppresses phosphorylation of AKT in KPL-4 cells. [2]
