Th17 cells contribute to combination MEK inhibitor and anti-PD-L1 therapy resistance in KRAS/p53 mutant lung cancers

Recent clinical trials combining MEK inhibitors with anti-PD-L1 in solid tumours show moderate responses. Here, the authors demonstrate that the combination of MEK inhibition and PD-L1 blockade in KRAS mutant lung cancer models leads to a transient tumour regressions and resistance due to increased infiltration of Th17 cells and that the triple therapy targeting MEK, PD-L1 and IL-17 produced better in vivo responses.