Multisystem Immune-Related Adverse Events Associated with Immune Checkpoint Inhibitors for Treatment of Non-Small Cell Lung Cancer

Importance: The spectrum of individual immune-related adverse events (irAEs) from anti-programmed cell death 1 (PD-1) and programmed cell death ligand 1 (PD-L1) immune checkpoint inhibitors (ICIs) has been reported widely, and their development is associated with improved patient survival across tumor types. The spectrum and impact on survival for patients with non-small cell lung cancer (NSCLC) who develop multisystem irAEs from ICIs, has not been described. Objective: To characterize multisystem irAEs, their association with survival, and risk factors for multisystem irAE development. Design, Setting, and Participants: This retrospective cohort study carried out in 5 academic institutions worldwide included 623 patients with stage III/IV NSCLC, treated with anti-PD-(L)1 ICIs alone or in combination with another anticancer agent between January 2007 and January 2019. Exposures: Anti-PD-(L)1 monotherapy or combinations. Main Outcomes and Measures: Multisystem irAEs were characterized by combinations of individual irAEs or organ system involved, separated by ICI-monotherapy or combinations. Median progression-free (PFS) and overall survival (OS) were estimated using the Kaplan-Meier method. Differences in PFS and OS between irAE groups were assessed by multivariable models. Risk for multisystem irAE was estimated as odds ratios by multivariable logistic regression. Results: The 623 patients included in the study were mostly men (60%, n = 375) and White (77%, n = 480). The median (range) age was 66 (58-73) years, and 148 patients (24%) developed a single irAE, whereas 58 (9.3%) developed multisystem irAEs. The most common multisystem irAE patterns in patients receiving anti-PD-(L)1 monotherapy were pneumonitis thyroiditis (n = 7, 14%), hepatitis thyroiditis (n = 5, 10%), dermatitis pneumonitis (n = 5, 10%), and dermatitis thyroiditis (n = 4, 8%). Favorable Eastern Cooperative Oncology Group (ECOG) performance status (PS) (ECOG PS = 0/1 vs 2; adjusted odds ratio [aOR], 0.27; 95% CI, 0.08-0.94; P =.04) and longer ICI duration (aOR, 1.02; 95% CI, 1.01-1.03; P <.001) were independent risk factors for development of multisystem irAEs. Patients with 1 irAE and multisystem irAEs demonstrated incrementally improved OS (adjusted hazard ratios [aHRs], 0.86; 95% CI, 0.66-1.12; P =.26; and aHR, 0.57; 95% CI, 0.38-0.85; P =. 005, respectively) and PFS (aHR, 0.68; 95% CI, 0.55-0.85; P =.001; and aHR, 0.39; 95% CI, 0.28-0.55; P <.001, respectively) vs patients with no irAEs, in multivariable models adjusting for ICI duration. Conclusions and Relevance: In this multicenter cohort study, development of multisystem irAEs was associated with improved survival in patients with advanced NSCLC treated with ICIs.