Abstract
Despite the success of PD-1 blockade in melanoma and other cancers, effective treatment strategies to overcome resistance to cancer immunotherapy are lacking1,2. We identified the innate immune kinase TANK-binding kinase 1 (TBK1)3 as a candidate immune evasion gene in a pooled genetic screen4. Using a suite of genetic and pharmacologic tools across multiple experimental model systems, we confirm a role for TBK1 as an immune evasion gene. Targeting TBK1 enhances response to PD-1 blockade by lowering the cytotoxicity threshold to effector cytokines (TNFα/IFNγ). TBK1 inhibition in combination with PD-1 blockade also demonstrated efficacy using patient-derived tumour models, with concordant findings in matched patient-derived organotypic tumour spheroids (PDOTS) and matched patient-derived organoids (PDOs). Tumour cells lacking TBK1 are primed to undergo RIPK- and caspase-dependent cell death in response to TNFα/IFNγ in a JAK/STAT-dependent manner. Taken together, our results demonstrate that targeting TBK1 is a novel and effective strategy to overcome resistance to cancer immunotherapy.
