The oncogenic receptor tyrosine kinases AXL and c-Met are over-expressed and constitutively activated in a variety of human cancers. Activation of these receptors contributes to multiple steps in tumor progression by promoting cancer cell migration and invasion, enhancing tumor angiogenesis, facilitating cancer cell survival and tumor growth, and contributing to tumor resistance to several chemotherapy and molecular-targeted therapeutic agents. CEP-40783 is an orally active, potent and selective AXL and c-Met kinase inhibitor, with enzyme IC50 values of 7 nM and 12 nM, respectively. In AXL-transfected 293GT cells, CEP-40783 was 27-fold more active compared to recombinant enzyme with an IC50 value of 0.26 nM. Comparably high cellular potency was observed in NCI-H1299 human NSCL cells. CEP-40783 also demonstrated superior activity against c-Met in GTL-16 cells (IC50 = 6 nM). The increased inhibitory activity of CEP-40783 in cells could be attributed to its extended residence time on both AXL and c-Met, consistent with a Type II mechanism. The prolonged residence time of CEP-40783 at the target may provide for improved in vivo efficacy, selectivity and therapeutic index. Additionally, CEP-40783 showed high kinome selectivity against 298 kinases with an S90 of 0.04 (fraction of kinases showing >90% inhibition at 1 µM). In PK/PD studies, CEP-40783 showed dose- and time-dependent inhibition of AXL phosphorylation using NCI-H1299 NSCL xenografts with ∼80% target inhibition at 0.3 mg/kg 6 h post dose and complete target inhibition to >90% inhibition at 1 mg/kg between 6-24 h, while a 10 mg/kg po dose resulted in complete AXL inhibition up to 48 h post dosing. In AXL/NIH3T3 xenografts, 0.3 mg/kg po resulted in complete tumor regressions. CEP-40783 was also efficacious in reducing spontaneous lymph node and pulmonary metastatic tumor burden in the MDA-MB-231-luc and 4T1-luc orthotopic breast cancer models, respectively, at 10 and 30 mg/kg po. PK/PD evaluation of the c-Met activity of CEP-40783 (10, 30, 55 mg/kg po qdX5d) showed significant to complete inhibition of c-Met phosphorylation in GTL-16 gastric carcinoma xenografts. Efficacy studies in GTL-16 xenografts demonstrated significant anti-tumor efficacy (tumor stasis and regressions) at 10 and 30 mg/kg po. In EBC-1 NSCL xenografts, administration of CEP-40783 (3, 10 and 30 mg/kg, po qd) resulted in dose-related efficacy, with tumor stasis at 3 mg/kg, tumor regressions and >96% TGI at 10 mg/kg. In all studies CEP-40783 was well tolerated with no compound-related body weight loss. CEP-40783 demonstrated potent AXL and c-Met pharmacodynamic and anti-tumor efficacy in established tumor xenograft models, having potential therapeutic utility in multiple human tumor types in which c-Met and AXL activity play a critical role in tumor formation, local invasion and metastasis. Studies in primary human tumorgrafts are in progress.

Citation Information: Mol Cancer Ther 2013;12(11 Suppl):C275.

Citation Format: Sheila Miknyoczki, Mangeng Cheng, Robert Hudkins, Thelma Angeles, Lisa Aimone, Jean Husten, Jie Qian, Seetha Murthy, Thomas Conners, Robert Bendesky, Amy Landis, Jennifer Grobelny, Hong Chang, Bruce Dorsey, Mark Ator, Bruce Ruggeri. CEP-40783: A potent and selective AXL/c-Met inhibitor for use in breast, non-small cell lung (NSCLC), and pancreatic cancers. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2013 Oct 19-23; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2013;12(11 Suppl):Abstract nr C275.