Abstract 2209: Novel therapeutic agents for RET-driven cancers, which is highly potent and selective inhibitor to RET kinase

Abstract

Abstract The rearranged during transfection (RET) tyrosine kinase is mostly altered by fusion and it makes RET as a attractive therapeutic target for medullary thyroid cancer and non-small cell lung cancer (NSCLC). Multi-kinase inhibitors (mKIs) such as cabozantinib and vandetanib expressed poor tolerability and limited efficacy due to off-target kinase inhibitory activity in academia and clinical cases. As for selective RET inhibitor, compounds such as BLU-667 and LOXO-292 are under development, currently in clinical trials. We are currently developing potent and selective RET inhibitors to address unmet medical needs for RET-driven cancers. Our team has validated its high potency and selectivity via kinase profiling and in-vitro assay results. We also anticipate our compound to overcome certain mutation, such as V804M. Our compounds strongly suppress phosphorylation of RET in tumor cells with various RET fusions and mutations by inhibiting proliferation at below 10 nM. This potency result is higher than those of other mKIs with RET inhibitory activity. The inhibitory concentration of our compounds to VEGFR2 is more than dozens of fold compared with RET. In addition, our compounds reveal low cytotoxicity in Ba/F3 naïve cells in the 1 µM concentration. These findings lead us to conclude that our compounds can be potent and highly selective inhibitors of RET kinase, a potential novel therapeutic agents for RET-driven cancers. Citation Format: Hua Li, SeoHyun Jo, Woomi Do, Hyunkyung Kim, Hwan Kim, Kyung-ah Seo, Ji-hoon Oh, Jieun Choi, Jaeyoung Ahn, Jung Beom Son, Nam Doo Kim. Novel therapeutic agents for RET-driven cancers, which is highly potent and selective inhibitor to RET kinase [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 2209.