Divergent clinical and immunologic outcomes based on STK11 co-mutation status in resectable KRAS-mutant lung cancers following neoadjuvant immune checkpoint blockade

Co-mutations of the KRAS and STK11 genes in advanced non-small cell lung cancer (NSCLC) are associated with immune checkpoint blockade (ICB) resistance. While neoadjuvant chemoimmunotherapy is now a standard of care treatment for early-stage NSCLC, the clinical and immunologic impact of KRAS and STK11 co-mutations in this setting are unknown. We evaluated the clinical outcomes and intratumoral T cell profiles of resected KRAS-mutant tumors treated with neoadjuvant ICB. Relative to KRASmut/STK11wt tumors, KRASmut/STK11mut exhibited significantly higher recurrence risk. Single-cell transcriptomics showed enhanced oxidative phosphorylation with evidence of decreased PGE-2 signaling and increased IL-2 signaling in CD8+ tumor-infiltrating lymphocytes (TIL) from KRASmut/STK11mut tumors, a finding that was mirrored in KRASwt tumors that relapsed. TIL from KRASmut/STK11mut tumors expressed high levels of molecules associated with tumor residence, including CD39 and ZNF683 (HOBIT). These divergent T cell transcriptional fates suggest T cell maintenance and residence may be detrimental to anti-tumor immunity in the context of neoadjuvant ICB for resectable NSCLC, regardless of KRAS mutation status. Our work provides a basis for future investigations into the mechanisms underpinning PGE-2 and IL-2 signaling as they relate to T cell immunity to cancer and to divergent clinical outcomes in KRASmut/STK11mut NSCLC treated with neoadjuvant ICB. Overall design: To better understand the immunological underpinnings of the increased risk of recurrence in patients with KRASmut/STK11mut tumors, we performed single cell TCRseq/RNAseq on biospecimens from 6 patients with KRASmut/STK11mut disease and 7 patients with KRASmut/STK11wt disease treated with neoadjuvant ICB. All KRASmut/STK11mut tumors were confirmed to have functionally and/or clinically relevant STK11 mutations.