Development of highly potent and selective oncogenic KRASG12D PROTAC degraders

As a key driver of tumorigenesis and cancer development, the KRAS G12D mutation is ubiquitous existed in KRAS-associated malignancies, highlighting the urgent clinical need for effective KRAS G12D targeting drugs. In this study, through rational design and multiple cell type-based antiproliferative evaluation, we identified a novel KRAS G12D inhibitor, Y-I-1 , which demonstrated remarkable anti-cancer activity. Subsequent computational analyses including molecular dynamics (MD) simulations, binding free energy calculations, umbrella sampling, and protein-ligand docking revealed its excellent binding characteristics, rationalizing the observed potency. Building upon the structure of Y-I-1 , we constructed proteolysis-targeting chimera (PROTAC) by conjugating it with different linker moieties and VH032. Among them, degrader Y-D-2 potently and selectively exhibited nanomolar inhibitory IC 50 , degradation DC 50 values, and more than 95 % maximum degradation (D max ) in KRAS G12D -mutant cancer cells via ubiquitin proteasome-involving pathway, accompanied by nanomolar IC 50 efficiency for phosphorylated ERK (pERK) inhibition. Mechanistically, Y-D-2 significantly induced cell apoptosis, G1 cell cycle arrest and inhibited cell migration and invasion. Notably, Y-D-2 led to significant tumor growth inhibition in the GP2D xenograft model with well-tolerated dose-schedules with favorable PK properties. This study not only provides an important theoretical basis for the optimal design of KRAS G12D degraders, but also highlights its potential for the treatment of KRAS G12D -driven cancers. • Novel KRAS G12D inhibitor Y-I-1 was developed via rational drug design and multiple cell type-based evaluation. • Y-I-1 was constructed with varied linkers and VH032 to develop KRAS G12D PROTACs. • Y-D-2 inhibits KRAS G12D -mutant cancer cells growth with nanomolar IC 50 values. • Y-D-2 potently and selectively induces KRAS G12D degradation with nanomolar DC 50 values. • Y-D-2 significantly inhibits GP2D tumor growth with TGI% rates more than 90 %.