Patients with Stage IIIB/IV lung adenocarcinoma harboring a sensitizing EGFR mutation and treated with first‐line, first or second‐generation TKI...69% received erlotinib...Compared to patients with PD‐L1 low/negative tumours those with high PD‐L1 (n = 9; 13%) had significantly shorter PFS...OS (10.8 vs 25.8 months, HR 0.22 95% CI 0.09‐0.58, P = .001).