Description:

Pembrolizumab has been approved for first-line locally advanced or metastatic NSCLC with a tumor proportion score (TPS) ≥50% for PDL1, based on the results of KEYNOTE-024. However, even with a positive PDL1 status, only a fraction of patients respond to immunotherapy. In the KEYNOTE-024 study evaluating pembrolizumab versus chemotherapy in first-line advanced NSCLC with PDL1 TPS ≥50%, the response rate in the pembrolizumab arm alone was 45%. NFE2L2 is a transcription factor that directs the expression of free radical defense genes that may interfere with radiation-induced DNA damage. KEAP1 is an adaptor protein that targets NFE2L2 for ubiquitination and proteasomal destruction as part of normal homeostasis. These new biomarkers are of clinical interest, as KEAP1/NFE2L2 mutations predict radiation resistance in patients with localized NSCLC treated with radiotherapy but not surgery. Some data also suggest a role for the KEAP1/NFE2L2 axis in response to immunotherapy. Establishing a predictive model for the presence of the KEAP1/NFE2L2 mutation would provide a tool for predicting survival (progression-free and overall), even before the patient starts immunotherapy.