Heterogeneous Outcomes of Immune Checkpoint Inhibitor Rechallenge in Patients With NSCLC: A Systematic Review and Meta-Analysis

INTRODUCTION: Outcomes of immune checkpoint inhibitor (ICI) rechallenge in NSCLC remain uncertain. This study estimated the safety and efficacy of ICI rechallenge and compared rechallenge benefit among different reasons of initial ICI discontinuation in NSCLC. METHODS: PubMed, EMBASE, and Cochrane Library were searched for studies on NSCLC retreated with ICI. Immune-related adverse events (irAEs), overall response rate (ORR), disease control rate (DCR), and progression-free survival (PFS) at initial ICI and rechallenge were analyzed. RESULTS: A total of 15 studies including 442 patients between 2018 and 2022 were eligible for meta-analysis. The incidence of grade 3 or 4 irAE was lower in rechallenge than initial ICI (8.6% versus 17.8%, p < 0.001). Patients rechallenged with ICI had lower ORR and DCR than initial ICI (13.2% versus 42.4%, p < 0.001; 51.1% versus 74.0%, p < 0.001). The ORR and DCR to ICI rechallenge were both higher in patients who experienced disease progression after stopping ICI or irAE than patients with disease progression during ICI treatment (ORR: 46.2% versus 20% versus 11.4%, p = 0.003; DCR: 84.6% versus 90.0% versus 55.0%, p = 0.002). In addition, 34.7% of 69 patients with individual response to ICI and PFS experienced the same or better response to ICI rechallenge in comparison with initial ICI, although PFS in initial ICI was longer than that in ICI rechallenge (median: 8.90 versus 3.67 mo, hazard ratio = 0.44, 95% confidence interval: 0.33–0.59). CONCLUSIONS: ICI rechallenge had less severe toxicity than initial ICI treatment. Patients undergoing disease progression after ICI cessation or ICI discontinuation owing to irAE are more likely to benefit from ICI rechallenge in NSCLC.