In vitro activity: BMS-833923 reduces hedgehog pathway activity, decreases cell proliferation and induces apoptosis via the intrinsic pathway in esophageal adenocarcinoma (EAC) cell lines. BMS-833923 dose-dependently affects canonical and prostate hedgehog signature gene transcription in vitro.

Kinase Assay: BMS-833923 (XL-139) is an orally bioavailable small-molecule inhibitor of Smoothened with potential antineoplastic activity; inhibits BODIPY cyclopamine binding to SMO in a dose-dependent manner with an IC50 of 21 nM.

Cell Assay: BMS-833923 inhibited the expression of GLI1 and PTCH1 in cell lines expressing wild-type SMO or activated mutant SMO with IC50 values in the range from 6 to 35 nM. In the FACS-based binding assays, it does-dependently suppressed cyclopamine binding to SMO with IC50 value of 21 nM. In the esophageal adenocarcinoma cell lines OE19 and OE33, treatment of BMS-833923 significantly reduced cell proliferation with IC50 values of both 10 μM. Besides that, BMS-833923 was found to inhibit the growth of multiple myeloma cells and the proportion of ALDH+ cancer stem cells. It also inhibited the growth of many other tumor cells derived from patients with hematological malignancies including ALL, AML and CM.