Abstract 6513: Discovery and characterization of a KRASG12C/D/V degrader with potent anti-tumor activity in KRASmut-driven preclinical models

Abstract KRAS mutations are one of the most common oncogenic drivers for multiple cancers. KRASG12X mutations are identified in approximately 25% of lung cancer, 24% of colorectal (CRC), and 79% of pancreatic ductal adenocarcinoma (PDAC). Although the approval of Sotorasib in 2021 by the FDA partially addressed the needs of patients with KRASG12C mutant, other mutations, such as G12D and G12V, still lack effective target therapies. Here, we report RD0255359, a proteolysis targeting chimera (PROTAC) KRASG12C/D/V degrader with highly potent cell viability and KRASG12C/D/V degradation ability. In vitro, RD0255359 exhibited a remarkable KRAS degradation property in NCI-H358 (G12C), AGS (G12D), and SW620 (G12V) cell lines at concentrations below 10 nM. RD0255359 suppressed the proliferation of these cells with nanomolar IC50 without affecting the viability of KRASWT or KRAS-independent cell lines. Meanwhile, using protease inhibitor MG132 or corresponding ligand pretreatment and VHLKD-AGS cell experiment confirmed that RD0255359-induced KRAS degradation was VHL and UPS dependent. In vivo, weekly IV injection of 1-10 mg/kg RD0255359 led to tumor growth suppression or tumor regression in PK-59 PDAC xenograft model. The in vivo PK/PD demonstrated that durable KRAS degradation could be achieved with once- weekly IV injection. Notably, after injection, the drug can distribute into tumor tissue rapidly and abundantly, and maintaining a high concentration till the next administration. Taken together, RD0255359 is a highly potent and selective KRASG12C/D/V degrader with favorable PK properties. It exhibits a promising therapeutic index in preclinical studies. Citation Format: Zhengqing Li, Renqi Xu, Xiaofeng Yang, Zhengyao Zou, Xiaoqiang Kong, Haibo Chen, Yongqing Sun, Ying Zhao, Jing Guo, Cheng Yang, Han Han, Xiaoyun Liu, Hong Lan, Lieming Ding, Quan Zhou, Hao Wu, Jiabing Wang. Discovery and characterization of a KRASG12C/D/V degrader with potent anti-tumor activity in KRASmut-driven preclinical models 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 6513.