MKC-8866

MKC-8866 is a potent, and selective IRE1 RNase inhibitor with an IC50 of 0.29 μM in human vitro. MKC-8866 strongly inhibits Dithiothreitol-induced X-box-binding protein 1-spliced (XBP1s) expression with an EC50 of 0.52 μM and unstresses RPMI 8226 cells with an IC50 of 0.14 μM. MKC-8866 also strongly inhibits prostate cancer (PCa) tumor growth as monotherapy in multiple preclinical models in mice and shows synergistic antitumor effects with current PCa drugs.