Objective:

To compare the efficacy and safety of continuing an immune checkpoint inhibitor beyond progression (CIBP) versus switching to a non-ICI regimen (non-CIBP) in patients with advanced gastric/gastroesophageal junction cancer (GC/GEJC) after first-line immuno-chemotherapy failure, acknowledging the retrospective nature of the study.

Key Findings:

• CIBP group had significantly improved median PFS (4.4 vs. 3.0 months; p<0.001).
• CIBP group had significantly improved median OS (9.5 vs. 6.4 months; p=0.0012).
• Survival benefits of CIBP remained significant after multivariable adjustment and propensity score matching.
• Subgroup analyses indicated greater benefits for patients with PD-L1 expression ≥1%, those with an objective response to first-line therapy, or first-line PFS ≥6 months.
• Safety profile was manageable and comparable between both groups.

Interpretation:

Continuing ICI beyond progression is associated with superior survival outcomes compared to switching to non-ICI regimens in selected patients.

Limitations:

• Single-center study may limit generalizability and introduce selection bias, potentially affecting the robustness of the findings.

Conclusion:

CIBP represents a valid and promising second-line strategy for selected patients with advanced GC/GEJC following first-line immuno-chemotherapy failure.