Nicewarner Pena, S. R. | Search bioRxiv

bioRxiv2026

Concurrent AXL inhibition enhances RAS and ERK inhibitor efficacy in KRAS-mutant pancreatic and lung cancer

Resistance limits the clinical efficacy of RAS inhibitors. We applied chemical and genetic screens and identified the AXL receptor tyrosine kinase as a driver of resistance to RAS-ERK inhibition. We determined that combination treatment with the AXL inhibitor bemcentinib (AXLi) together with the RAS(ON) multi-selective tri-complex inhibitor RMC-7977 (RASi) or the ERK-selective inhibitor SCH772984 (ERKi) significantly enhanced growth suppression in human KRAS-mutant pancreatic and lung cancer models. Combined AXLi and RASi treatment of human KRAS-mutant pancreatic cell line-derived xenograft tumors synergistically suppressed ERK activation and MYC expression, and caused tumor regression. Analyses of immunocompetent mouse allograft pancreatic tumor models revealed a largely tumor cell-intrinsic response to inhibitor treatment. We identified an unexpected mechanism whereby KRAS inhibition upregulated the AXL ligand GAS6, activating AXL but inducing an AXL-dependent adaptive resistance mechanism wherein AXL antagonizes RASi efficacy. Our observations support concurrent AXL inhibition as a strategy to enhance RAS inhibitor clinical efficacy. STATEMENT OF SIGNIFICANCEOur findings identify AXL as a driver of resistance to RAS inhibitors, establishing a combination strategy to overcome resistance and enhance RAS inhibitor therapeutic efficacy in KRAS-mutant cancer by maximally inhibiting oncogenic RAS signaling.

cancer biology↗

bioRxiv2025

Dordaviprone/ONC201 Activation of the ClpP Mitochondrial Protease Inhibits the Growth of KRAS-Mutant Pancreatic Cancer and Overcomes RAS Inhibitor Resistance

Pancreatic ductal adenocarcinoma (PDAC) is characterized by KRAS-driven oncogenic signaling and tumor growth. Blockade of the KRAS ERK-MAPK pathway via small molecule direct RAS inhibitors has shown clinical promise, but intrinsic and acquired resistance limit the efficacy of these inhibitors as single agents. To identify potential combination strategies, we first assessed the ability of dordaviprone/ONC201, an FDA-approved agent, to inhibit PDAC cell and organoid growth. We observed that ONC201 reduced the growth of a broad panel of KRAS-mutant PDAC cell lines, and that the expression of mitochondrial protease ClpP was required for this efficacy. Mechanistically, we observed that treatment with ONC201 led to inhibition of mitochondrial respiration, causing a compensatory increase in glycolysis. Furthermore, ONC201 caused ClpP-dependent activation of PI3K-AKT-mTOR signaling and concurrent PI3K and mTOR inhibition further enhanced ONC201 growth suppression. ONC201 demonstrated an additive effect when combined with a RAS(ON) multi-selective inhibitor RMC-7977 in PDAC cells and organoids. Finally, PDAC cell lines with acquired resistance to RMC-7977 or KEAP1 loss-driven resistance retained sensitivity to ONC201. We propose that concurrent treatment with ONC201 may delay onset of resistance to RAS inhibitor therapy. Statement of SignificanceClpP activation by dordaviprone/ONC201 suppressed PDAC cell growth and overcame resistance to the RAS(ON) multi-selective inhibitor RMC-7977, providing support for investigating this combination as a potential combination treatment for KRAS-mutant pancreatic cancer.

cancer biology↗