Abstract 1717: KRAS mutant gene editing prevents tumor growth in vivo and overcomes acquired resistance to KRASG12C inhibitor

Abstract Mutations on KRAS codon12 are among the most commonly observed mutations in pancreatic, colorectal and lung cancers. To date, only treatment targeting KRASG12C mutation have been successful in the clinic and approved. However, it is hampered by adaptive resistance, mainly associated with the emergence of other KRAS mutations and high amplification of KRASG12C allele. We have developed a new potent strategy combining gene editing with a tumor selective nanocarrier, to impair cancer cell proliferation by directly targeting G12D, G12V,and G12C mutations of the KRAS oncogene. ADGN-121, ADGN-122 and ADGN-123 are gene-editing complexes containing proprietary sgRNA targeting KRASG12D, KRASG12V or KRASG12C with mRNACas9 complexed with proprietary short amphipathic peptides that form stable neutral nanoparticles. The complexes were evaluated on pancreas, colorectal and lung cancer cells harboring KRASG12D, V, or C mutations. KRAS mutant indel frequency was evaluated by T7E1 method. In-vivo efficacy of IV-administered ADGN/mRNACas9gRNA (0.25-1.0mg/kg, 2 injections at day 1 & 7) was evaluated in Panc1 (KRASG12D) and SW403 (KRASG12V) mouse xenografts. ADGN-123 in combination with AMG-510 (KRASG12C inhibitor) was evaluated on H358, PACA2 and SW837 cells, exhibiting an acquired resistance to AMG-510. ADGN-121,-122 and -123 efficiently and selectively silenced KRASG12D, KRASG12V KRASG12C , respectively, in colorectal, pancreatic and lung cancer cells resulting in reduction of cell proliferation by 80% and inhibition of ERK and/or AKT phosphorylation. Only two IV-administrations of ADGN-121 containing gRNAG12D abolished Panc1 tumor growth in a dose dependent manner, resulting in tumor regression of 60-70% at 1.0mg/kg. ADGN-122 containing gRNAG12V abolished SW403 tumor growth with a tumor regression of 70% at 1.0 mg/kg. In contrast, no effect on tumor growth was observed with nonspecific gRNA. The combinations of ADGNs with drugs currently used on clinic have been evaluated. We demonstrated a synergistic combination ADGN-121/Abraxane in pancreatic carcinoma and ADGN-122/Capecitabine in colon Adenocarcinoma. We showed, that ADGN-123 containing gRNAG12C can effectively reduce the proliferation and inhibit ERK and AKT phosphorylation of AMG-510 acquired resistance cells and that no resistance occurs after ADGN-123 treatment. ADGN treatments are well tolerated, no sign of clinical toxicity, inflammatory response or emergence of other KRAS mutation was detected after single or repeated administrations. ADGNs were effective in targeting selectively mutated KRAS both in vitro and in vivo. Our study provides a proof-of-concept that ADGN can be applied to target driver mutations of cancers in vivo and permanently disrupt the oncogenic alleles, leading to major tumor regression. ADGN-123 can be used as a strategy to overcome resistance associated to small molecule inhibitors of KRASG12C. Citation Format: Gilles Divita, Veronica Guzman-Gonzales, Audrey Grunenberger, Elodie Czuba, Melanie Guidetti, Veronique Josserand, Neil Desai. KRAS mutant gene editing prevents tumor growth in vivo and overcomes acquired resistance to KRASG12C inhibitor [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 1717.