A neomorphic protein interface catalyzes covalent inhibition of RAS <sup>G12D</sup> aspartic acid in tumors
Caroline E. Weller, G. Leslie Burnett, Lingyan Jiang, Sujata Chakraborty, Dongyu Zhang, Nicole A. Vita, Julien Dilly, Eejung Kim, Benjamin J. Maldonato, Kyle J. Seamon, Diane F. Eilerts, Anthony N. Milin, Abby Marquez, Jessica N. Spradlin, Ciara Helland, Andrea Gould, Tamar Bar Ziv, Phuong Uyen Dinh, Shelby L. Steele, Zhican Wang, Yunming Mu, Seema Chugh, Hanrong Feng, Connor J. Hennessey, Junning Wang, Jennifer A. Roth, Matthew G. Rees, Melissa M. Ronan, Brian M. Wolpin, William C. Hahn, Matthew Holderfield, Zhengping Wang, Elena S. Koltun, Mallika Singh, Adrian L. Gill, Jacqueline A.M. Smith, Andrew J. Aguirre, Jingjing Jiang, John E. Knox, David Wildes
Abstract
Mutant RAS proteins are among the most prevalent drivers of human cancer, and the glycine to aspartic acid mutation at codon 12 (G12D) is the most common variant. Mutation-selective covalent inhibitors spare RAS in healthy tissue and enable extended pharmacodynamic effect, but covalent targeting of RAS G12D is hindered by low nucleophilicity and high proteomic abundance of carboxylic acids. We overcame these challenges with compounds that bind cyclophilin A (CYPA) to create a neomorphic protein-protein interface between CYPA and active RAS that enables selective, enzyme-like rate enhancement of the covalent reaction between D12 and electrophilic warheads with exceptionally low intrinsic reactivity. This approach yielded orally bioavailable compounds with marked antitumor activity in multiple preclinical models of KRAS G12D cancers, including the investigational agent zoldonrasib (RMC-9805) currently undergoing clinical evaluation (NCT06040541).