Administration of anti-programmed cell death protein 1 (anti-PD-1) is now standard therapy in advanced non-small cell lung cancer (NSCLC). However, immune checkpoint inhibitors, including anti-PD-1, have not been assessed in patients with subclinical disease with advanced NSCLC, and no useful clinical biomarkers have been associated with immune-related adverse events (irAEs) among these patients treated with anti-PD-1.To assess the safety and efficacy of anti-PD-1 treatment in patients with subclinical disease with advanced NSCLC and with or without preexisting autoimmune markers, including rheumatoid factor, antinuclear antibody, antithyroglobulin, and antithyroid peroxidase; and to assess potential clinical biomarkers that may be meaningfully and conveniently associated with clinical benefit or with irAEs following anti-PD-1 treatment.This medical records analysis retrospectively evaluated 137 patients who received nivolumab or pembrolizumab monotherapy at Sendai Kousei Hospital in Japan between January 2016 and January 2018. Treatment efficacy and irAEs were evaluated along with candidate factors that may be associated with irAEs.Absence or presence of specific autoimmune markers and antibodies before treatment.Preexisting antibodies and autoimmune markers, progression-free survival (PFS), and irAEs.Of 137 patients with advanced NSCLC, 105 were men, the median age was 68 (range, 36-88) years, 99 underwent nivolumab monotherapy, 38 underwent pembrolizumab monotherapy, and 134 had an Eastern Cooperative Oncology Group performance status of 0 or 1. The median PFS was 6.5 (95% CI, 4.4-12.9) months among patients with examined preexisting antibodies and 3.5 (95% CI, 2.4-4.1) months among patients without, suggesting significantly better prognosis in the former. The hazard ratio for disease progression or death in the presence of the examined preexisting antibodies was 0.53 (95% CI, 0.36-0.79; P = .002). The PFS was significantly longer among patients with any preexisting antibodies than among those without. The examined preexisting antibodies (48 patients [73%]) and rheumatoid factor (26 patients [39%]) were more common among patients who developed irAEs. Multivariate analysis indicated that the presence of the examined preexisting antibodies was independently associated with irAEs (odds ratio, 3.25; 95% CI, 1.59-6.65; P = .001). Skin reactions were more frequent among patients with preexisting rheumatoid factor (47% vs 24%, P = .02), whereas thyroid dysfunction was more frequent among patients with preexisting antithyroid antibodies (20% vs 1%, P < .001).The presence of the examined preexisting antibodies was associated with clinical benefit and with the development of irAEs in patients with NSCLC treated with nivolumab or pembrolizumab. Thus, the presence of these autoimmune markers may help determine the risk-benefit ratio for individual patients with NSCLC, maximizing therapeutic benefits while minimizing irAEs.

Profiling Preexisting Antibodies in Patients Treated With Anti–PD-1 Therapy for Advanced Non–Small Cell Lung Cancer