Efficacy, prognosis and safety analysis of anti-PD-1/PD-L1 inhibitor rechallenge in advanced lung cancer patients: a cohort study.

Background: The rechallenge of immune checkpoint inhibitors (ICI) is now an optional strategy for patients who discontinued ICI due to immune-related adverse events (irAEs) or disease progression. However, little data is available for the prognosis and prognostic factors of patients receiving ICI rechallenge treatment in advanced lung cancer patients. Our study aimed to explore the efficacy, prognosis and safety of patients who received anti-programmed cell death-1/programmed cell death ligand 1 (anti-PD-1/PD-L1) inhibitor rechallenge. Methods: In our retrospective cohort study, data of advanced lung cancer patients who received anti-PD-1/PD-L1 inhibitor and discontinued due to irAEs or disease progression were collected from December 2016 to August 2021. Enrolled patients were categorized into two groups: rechallenge group (R group) and non-rechallenge group (NR group). Progression-free survival (PFS), overall survival (OS), disease control rate (DCR) and safety data were analyzed. Cox model and subgroup analysis were analyzed according to baseline characteristics, ICI type, the reason for discontinuing ICI, etc. According to Response Evaluation Criteria in Solid Tumors Version 1.1 (RECIST 1.1), evaluation was performed routinely every 6-8 weeks after initiating treatment with the PD-1/PD-L1 inhibitor. The last follow-up in the study was on September 20, 2021. Results: Eighty-one patients who met our inclusion criteria were enrolled. In the whole cohort, the R group achieved better OS than the NR group [hazard ratio (HR) =0.176; 95% confidence interval (CI): 0.065-0.477; P=0.001). In the irAEs group, the survival analyses showed a trend toward improved OS in the rechallenge subgroup (HR =0.287; 95% CI: 0.081-1.025; P=0.055), and a promising DCR of 75% after an ICI rechallenge. Additionally, the exploration of safety outcomes indicated an acceptable recurrence rate (22.5%) of irAEs and an early onset of irAEs after an ICI rechallenge. In the disease progression group, the rechallenge subgroup did not improve OS (HR =0.214; 95% CI: 0.027-1.695; P=0.144), and the DCR of the rechallenge subgroup was 40% after ICI rechallenge. Conclusions: ICI rechallenge might be an attractive option for patients who discontinue treatment due to irAEs. For patients with disease progression, further research should be conducted. The recurrence of irAEs and their early onset during the second round of ICI should be considered.