AbstractIntroduction Even though PD-(L)1 inhibitors have dramatically changed the prognosis of patients with advanced non-small-cell lung cancer (NSCLC), resistance to treatment remains common. Rechallenge with PD-(L)1 based regimens has been explored in this context, but clinical benefit remains uncertain. Methods Two independent reviewer teams performed parallel searches of MEDLINE and EMBASE from 2019 to 2025 to identify clinical trials evaluating PD-(L)1 inhibitor based rechallenge strategies in patients with advanced NSCLC previously treated with PD-(L)1-based regimens. Randomised controlled trials (RCTs) were included in quantitative meta-analysis, while non-randomised single-arm studies were synthesised descriptively. The primary endpoint was overall survival (OS). Sensitivity analyses examined outcomes according to resistance pattern. All analyses used fixed-effects models. Findings A total of 10 RCTs (n = 3,081) and 106 non-randomised interventional trials were included. Across RCTs, PD-(L)1 based rechallenge strategies yielded modest improvements in both OS (HR 0.91, 95%CI: 0.82–0.99) and PFS (HR 0.89, 95%CI: 0.81–0.99) compared with the control arms, with no improvement in objective response rate (ORR). In sensitivity analyses, no benefit was observed in patients with primary resistance, whereas those with acquired resistance features (i.e., clinical benefit to prior immunotherapy) demonstrated a more favourable effect (HR 0.86, 95%CI: 0.77–0.97). A more restrictive analysis excluding patients with Conclusions In the largest synthesis of rechallenge strategies to date, PD-(L)1 rechallenge produced statistically significant but clinically marginal improvements in OS and PFS compared with standard treatments, with no benefit in patients with primary resistance. A signal of benefit was observed in patients with acquired resistance to prior immunotherapy although this exploratory analysis was limited by heterogeneous resistance definitions across trials and a non-significant interaction test.
Marinelli et al. (Fri,) studied this question.