Efficacy of immune checkpoint inhibitor rechallenge in initial immunotherapy responders with advanced non-small cell lung cancer: A single-center retrospective study.

Background: The efficacy of immune rechallenge in patients with advanced non-small cell lung cancer (NSCLC) who responded well to initial immune checkpoint inhibitor (ICI) treatment is becoming a research hotspot. This study was aimed at describing the survival and clinical characteristics after immune rechallenge in initial immunotherapy responders.

Patients and methods: We retrospectively identified 104 patients with advanced NSCLC who responded well in the first ICI and were rechallenged with immunotherapy to treat progression between January 2018 and June 2023 at Zhejiang Cancer Hospital. Progression-free survival (PFS) 2 and overall survival (OS) were defined as the time from the first day of the second ICI to the date of progression, death, or last follow-up.

Results: Of 104 enrolled patients, 33 received immune monotherapy, and 71 were rechallenged with combination therapy (34 combined with anti-angiogenesis therapy). Patients with an initial immunotherapy duration exceeding 12 months, compared with a duration within 12 months, achieved a significantly prolonged mPFS2 and mOS (PFS2: 9.2 vs. 3.4 months, P < 0.001; OS: 25.5 vs. 10.7 months, P = 0.006). Patients rechallenged with combination therapy had significantly longer PFS2 than those receiving monotherapy (5.8 vs. 2.5 months, P = 0.040), and showed a favorable OS trend (15.9 vs. 10.1 months, P = 0.301). A significant difference in PFS2, particularly for patients receiving combined treatment with anti-angiogenesis therapy (8.7 vs. 4.6 months, P = 0.011), and a tendency toward longer OS (25.3 vs. 13.7 months, P = 0.090), were observed. Multivariate analysis identified long-term treatment duration (P = 0.005) and combined treatment with anti-angiogenesis therapy (P = 0.030) as independent positive factors associated with PFS after rechallenge.

Conclusion: Immune rechallenge is recommend for responders with a prolonged initial immunotherapy duration. Combination therapy, particularly that including anti-angiogenic therapy, is an alternative effective approach to immune rechallenge.