Abstract 3313: Discovery of a potent, selective, and orally available small molecule for disruption of the SOS1-RAS interaction

Abstract KRAS mutations represent one of the most common genetic alterations in many cancers including non-small cell lung cancer (NSCLC), pancreatic ductal adenocarcinoma (PDAC), and colorectal cancer (CRC). While Sotorasib and Adagrasib, KRAS G12C inhibitors, have received approval, they exhibit limited responsiveness in clinical trials and are not applicable to various other KRAS mutation types. SOS1 (Son of Sevenless 1) functions as a guanine nucleotide exchange factor (GEF) on RAS, facilitating the transition of inactive GDP-bound RAS to its active GTP-bound state. In addition, SOS1 plays a pivotal role in negative feedback by actively contributing to the reactivation of ERK during treatment with inhibitors targeting the RTK/RAS/MAPK pathway. Inhibiting SOS1, which impedes the reactivation of ERK, has the potential to enhance the effectiveness of inhibitors targeting the RTK/RAS/MAPK signaling cascade and prevent the emergence of resistance mechanisms via H-RAS and N-RAS bypass pathways. Therefore, combining the inhibition of SOS1 with inhibitors targeting the RTK/RAS/MAPK pathway may enhance outcomes and mitigate relapse associated with observed resistances. Here, we present the discovery of a potent, selective, and orally bioavailable small molecule SOS1 inhibitor that effectively disrupts the interaction between SOS1 and RAS. It has demonstrated remarkable synergy effects with RTK/RAS/MAPK pathway inhibitors, significantly impeding the growth of tumors carrying KRAS or EGFR mutations in vivo. Overall, our development candidate has demonstrated significant therapeutic potential in combination with inhibitors targeting the RTK/RAS/MAPK pathway for cancers bearing activating mutations in this pathway. Citation Format: Dong Hyuk Ki, Hana Yu, Donggeon Kim, Yeejin Jeon, Seongin Jo, Joonwoo Nam, Eun-Jung Kim, Sungeun Kim, Hunmi Choi, Jieun Kim, Jihyun Yu, Sungpil Choi, Wooseok Han. Discovery of a potent, selective, and orally available small molecule for disruption of the SOS1-RAS interaction abstract. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts) ; 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84 (6Suppl): Abstract nr 3313.