Background and purpose: With the increasing application of immune checkpoint inhibitors in lung cancer

immune-related adverse event (irAE) has attracted more and more attention. This study aimed to analyze the occurrence of irAE in patients receiving single-drug immunotherapy and the correlation between irAE and immunotherapy efficacy. Methods: Data of patients with advanced non-small cell lung cancer (NSCLC) treated with anti-programmed death-1 (PD-1) monotherapy in Shanghai Pulmonary Hospital

Tongji University from June 2015 to Janurary 2019 were collected. Patients’ baseline clinical data

irAE types

occurrence time

severity

management of irAE

the objective response rate (ORR)

disease control rate (DCR) and progression-free survival (PFS) were retrospectively analyzed. And then

we used the SPSS 23.0 software to explore the correlation between irAE and PFS. Results: One hundred and nine advanced NSCLC patients were treated in our hospital. The median age of the patients was 64 years (range 32-82 years). The ratio of male to female was 89∶20. The ECOG performance status scores of 0

1 and 2 were 4

103 and 2 cases respectively. The number of patients who received the first-line

second-line and third-line and above treatment were 15

65 and 29 respectively. At the data cutoff

irAE occurred in 63 patients (57.8%). Among them

43 cases had complex irAE. The most common irAE were skin adverse events (n=28

25.7%). Other irAE were liver dysfunction (n=18

16.6%)

fatigue (n=16

14.7%)

endocrine toxicity (n=15

13.8%)

immune-related pneumonitis (n=12

11.0%) and gastrointestinal toxicity (n=10

9.2%). Most irAE occurred between 6 and 27 weeks. Ten patients (9.2%) had grade 3-4 irAE

mainly immune-related pneumonitis. Among the overall population

ORR was 24.7%

DCR was 77.9%

and median PFS was 4.6 months (95% CI: 3.9-5.2). Patients with irAE had significantly higher ORR compared with patients who did not have irAE (36.5% vs 8.7%

P=0.001). Similarly

the median PFS among patients with irAE was longer than patients without irAE (8.7 months vs 3.5 months

HR=0.294

95% CI: 0.184-0.469

P0.001). Among them

skin adverse events were most correlated with prognosis (median PFS: 12.7 months vs 4.3 months

HR=2.332

95% CI: 1.184-4.595

P=0.014). Conclusion: Most cases of irAE in immunotherapy of lung cancer occurred in 6-27 weeks of treatment

and most of them were grade 1-2. Grade 3-4 irAE were mostly immune-related pneumonitis. Development of irAE was associated with survival outcome.