Non-small Cell Lung Cancer Treated by an Anti-programmed Cell Death-1 Antibody without a Flare-up of Preexisting Granulomatosis with Polyangiitis

The safety and efficacy of anti-programmed cell death-1 (PD-1) antibodies in patients with granulomatosis with polyangiitis (GPA) still remain unclear. An 83-year-old man with GPA that was well controlled with immunosuppressive therapy was diagnosed with a postoperative recurrence of non-small cell lung cancer (NSCLC). Because the programmed cell death ligand 1 (PD-L1) tumor proportion score was 90%, pembrolizumab was administered. After 10 cycles, immune-related adverse events or GPA flare was not observed, and the patient showed an antitumor response. Anti-PD-1 antibody should therefore be considered a treatment option for PD-L1-high-expressing NSCLC patients with well-controlled GPA.