Immunotherapy beyond progression in patients with advanced non-small cell lung cancer

BACKGROUND: Immune checkpoint inhibitors (ICIs) represent a great breakthrough in the treatment of advanced non-small cell lung cancer (aNSCLC). However, whether immunotherapy beyond progression (IBP) is effective for aNSCLC has yet to be established. Therefore, a retrospective clinical study was conducted to investigate the efficacy of IBP in patients with aNSCLC under real-world conditions. METHODS: A total of 125 Chinese patients with aNSCLC who experienced progressive disease (PD) after receiving monotherapy or combination therapy (combined with chemotherapy or/and antiangiogenic therapy) with programmed cell death-1 (PD-1)/programmed cell death ligand-1 (PD-L1) inhibitors between January 2015 and March 2019 were enrolled. Patients who were treated with ICIs for more than 6 weeks after PD were defined as IBP (n=39), while those who received ICI treatment for less than 6 weeks or discontinued it due to PD were defined as non-IBP (n=86). Patient clinical characteristics were evaluated. An optimization-based method was applied to balance the clinical baseline characteristics between the two groups. RESULTS: In total population, the IBP group had longer overall survival (median OS, 26.6 vs. 9.5 months; HR, 0.40; 95% CI: 0.23–0.69; P<0.001) and progression-free survival (median PFS, 8.9 vs. 4.1 months; HR, 0.41; 95% CI: 0.26–0.65; P<0.001), compared with the non-IBP group. Despite no significant difference in objective response rate (ORR, 15.4% vs. 11.6%, P=0.560), disease control rate (DCR) was significantly higher in the IBP group (89.7% vs. 61.6%, P<0.001). After balancing baseline covariates, the IBP group also had longer OS (median: 26.6 vs. 10.7 months; HR, 0.40; 95% CI: 0.19–0.84; P=0.015) and PFS (median: 9.7 vs. 4.3 months; HR, 0.28; 95% CI: 0.15–0.51; P<0.001), with a benefit in either of patients previously treated with ICI monotherapy or in combination therapy and with non-response to the previously ICI. CONCLUSIONS: IBP is associated with longer OS and PFS in patients with aNSCLC. Our findings may suggest new therapeutic options for patients with aNSCLC who experienced disease progression after initial immunotherapy.