Response to first-line pembrolizumab in metastatic KRAS-mutated non-small-cell lung cancer

Aims: This retrospective study aims to identify a possible predictive role of KRAS mutations in non-small-cell lung cancer in response to first-line pembrolizumab, either as monotherapy or combined with chemotherapy. Methods: Patients received pembrolizumab alone (n = 213) or associated with chemotherapy (n = 81). Results: A mutation in the KRAS gene was detected in 27% of patients. In patients on pembrolizumab alone, median progression-free survival in KRAS-mutated cases was longer than in wild-type cases (11.3 vs 4.4 months; p = 0.019), whereas median overall survival did not reach statistical significance (22.1 vs 12.5 months; p = 0.119). Patients receiving chemo-immunotherapy with KRAS-positive tumors had a similar progression-free survival (9.7 vs 7.3 months; p = 0.435); overall survival data were immature. Conclusion: This study suggests a correlation between KRAS status and response to pembrolizumab.