The efficacy of ICIs rechallenge in advanced small cell lung cancer after progression from ICIs plus chemotherapy: A real-world study.

BACKGROUND

Rechallenging immune checkpoint inhibitors(ICIs) after resistance to initial ICIs plus chemotherapy(chemo-ICIs) remains uncertain in advanced small cell lung cancer(SCLC).

METHOD: The study retrospectively enrolled advanced SCLC patients who received ICIs after developing resistance to chemo-ICIs during hospitalization at Hunan Cancer Hospital from January 2020 to November 2023. The clinical outcomes and prognosis factors for ICIs rechallenge were further analyzed.

RESULTS

A total of 175 patients were included, of which 82(46.86 %) patients had primary resistance(PR) and 93(53.14 %) patients developed acquired resistance(AR). The progression-free survival(PFS), objective response rate (ORR), and disease control rate (DCR) of the total group were 3.3 months,16.57 %, and 53.71 %, respectively. The AR group exhibited significantly longer PFS compared to the PR group (4.5 months vs. 3.2 months, p = 0.012). In the PR group, a significantly longer PFS was found for ICIs rechallenge with interval treatment than without interval treatment(4.2 months vs. 3.1 months, p = 0.031). Within the AR group, the "new immunotherapy plus new chemotherapy" regimen showed a significantly longer PFS compared to the regimen of "maintain immunotherapy plus new chemotherapy" (8.3 months vs. 3.2 months, p = 0.014). The multivariate COX regression analyses demonstrated that both resistance pattern(p = 0.007) and treatment regimen(p = 0.039) independently served as risk factors for PFS in ICIs rechallenge.

CONCLUSION

Our study suggests that rechallenge of ICIs could be considered as a potential therapeutic strategy for advanced SCLC after progression from chemo-ICIs, particularly in patients with AR.