Continuing immune checkpoint inhibitors after progression: Real-world patterns of care and outcomes in second-line treatment for extensive-stage small-cell lung cancer.

Introduction: Small cell lung cancer (SCLC) is a highly malignant tumor with an extremely poor prognosis. In the currentera of immunotherapy, the role of immune checkpoint inhibitors (ICIs) in the second-line treatment of patients with extensive-stage SCLC (ES-SCLC) who have progressed to initial chemoimmunotherapy remains unclear.

Methods: A multicenter retrospective study were conducted, involving patients with ES-SCLC who received second-line (2L) therapy after progression to first-line chemoimmunotherapy. Patients were divided into 2L-ICIs group and 2L-non-ICIs group according to whether ICIs were added to the 2L treatment. The efficacy and adverse events of the two groups were analyzed and compared.

Results: A total of 103 patients were included in this study, with 53 in the 2L-ICIs group and 50 in the 2L-non-ICIs group. The 2L-ICIs group demonstrated a longer median progression-free survival (PFS) compared to the 2L-non-ICIs group (4.4 months vs 3.9 months, HR = 0.45, p = 0.001). Similarly, median overall survival was also prolonged in the 2L-ICIs group (10.0 months vs 6.9 months, HR = 0.56, p = 0.015). Cox regression analysis revealed that the addition of ICIs to 2L treatment was an independent prognostic factor for both PFS and OS in ES-SCLC patients. Subgroup analysis indicated that patients with a first-line PFS of ≥6 months could potentially benefit more from 2L ICIs. Furthermore, the occurrence of adverse events in the two groups exhibited a similar pattern.

Conclusion: For ES-SCLC patients who have progressed to first-line chemoimmunotherapy, adding ICIs to second-line treatment may be considered as an option with limited benefit but manageable adverse effects.