Simple Summary
The majority of patients with advanced non-small-cell lung cancer (NSCLC) who initially respond to treatment with immune checkpoint inhibitors (ICIs), will ultimately develop resistance within four years. ICI rechallenge is considered in real-world practice, but its effectiveness following disease progression is not well-established. The aim of this review was to evaluate the clinical efficacy of rechallenge ICI therapy following disease progression, based on the critical assessment of the published data. The evidence shows limited efficacy of rechallenge immunotherapy in unselected patient populations who progressed during initial immunotherapy, yet promising efficacy in those who relapsed after treatment completion.
Abstract
Immune checkpoint inhibitors (ICIs) are at the forefront of advanced non-small-cell lung cancer (NSCLC) treatment. Still, only 27–46% of patients respond to initial therapy with ICIs, and of those, up to 65% develop resistance within four years. After disease progression (PD), treatment options are limited, with 10% Objective Response Rate (ORR) to second or third-line chemotherapy. In this context, ICI rechallenge is an appealing option for NSCLC. Most data on the efficacy of ICI rechallenge are based on retrospective real-world studies of small, heavily pretreated, and heterogeneous patient groups. Despite these limitations, these studies suggest that ICI monotherapy rechallenge in unselected NSCLC patient populations who discontinued initial ICI due to PD is generally ineffective, with a median Progression-Free Survival (PFS) of 1.6–3.1 months and a Disease Control Rate (DCR) of 21.4–41.6%. However, there is a subpopulation that benefits from this strategy, and further characterization of this subgroup is essential. Furthermore, immunotherapy rechallenge in patients who discontinued initial immunotherapy following treatment protocol completion and progressed after an immunotherapy-free interval showed promising efficacy, with a DCR of 75–81%, according to post hoc analyses of several clinical trials. Future research on ICI rechallenge for NSCLC should focus on better patient stratification to reflect the underlying biology of immunotherapy resistance more accurately. In this review, we summarize evidence regarding rechallenge immunotherapy efficacy following NSCLC disease progression or relapse, as well as ongoing trials on immunotherapy rechallenge.