Co-targeting SOS1 enhances the antitumor effects of KRAS inhibitors by addressing intrinsic and acquired resistance.

Combination approaches are needed to strengthen and extend the clinical response to KRAS inhibitors (KRASi). Here, we assessed the antitumor responses of KRAS mutant lung and colorectal cancer models to combination treatment with a SOS1 inhibitor (SOS1i), BI-3406, plus the KRAS inhibitor, adagrasib. We found that responses to BI-3406 plus adagrasib were stronger than to adagrasib alone, comparable to adagrasib with SHP2 (SHP2i) or EGFR inhibitors and correlated with stronger suppression of RAS-MAPK signaling.

Reshaping the Tumor Microenvironment of KRASG12D Pancreatic Ductal Adenocarcinoma with Combined SOS1 and MEK Inhibition for Improved Immunotherapy Response.

Unlabelled: KRAS inhibitors have demonstrated exciting preclinical and clinical responses, although resistance occurs rapidly. Here, we investigate the effects of KRAS-targeting therapies on the tumor microenvironment using a library of KrasG12D, p53-mutant, murine pancreatic ductal adenocarcinoma-derived cell lines (KPCY) to leverage immune-oncology combination strategies for long-term tumor efficacy. Our findings show that SOS1 and MEK inhibitors (SOS1i+MEKi) suppressed tumor growth in syngeneic models and increased intratumoral CD8+ T cells without durable responses.

Drugging all RAS isoforms with one pocket.

Activating mutations in the three human RAS genes, , and , are among the most common oncogenic drivers in human cancers. Covalent KRAS inhibitors, which bind to the switch II pocket in the 'off state' of KRAS, represent the first direct KRAS drugs that entered human clinical trials. However, the remaining 85% of non-KRAS-driven cancers remain undrugged as do NRAS and HRAS and no drugs targeting the 'on state' have been discovered so far.

Systematic characterization of BAF mutations provides insights into intracomplex synthetic lethalities in human cancers.

Aberrations in genes coding for subunits of the BRG1/BRM associated factor (BAF) chromatin remodeling complexes are highly abundant in human cancers. Currently, it is not understood how these mostly loss-of-function mutations contribute to cancer development and how they can be targeted therapeutically. The cancer-type-specific occurrence patterns of certain subunit mutations suggest subunit-specific effects on BAF complex function, possibly by the formation of aberrant residual complexes.