Complete response and survival outcomes in patients with advanced cancer on immune checkpoint inhibitors

Aim: To evaluate overall survival in advanced cancer patients who achieved complete response (CR) with immune checkpoint inhibitor (ICI) therapy. Methods: This retrospective study included patients with advanced unresectable or metastatic cancer who received at least one cycle of palliative-intent ICI. Best overall response was used to define response groups. Results: 21 (7%) of 322 patients achieved CR. Multivariate analysis demonstrated that CR was independently associated with better overall survival compared with disease progression (hazard ratio: 0.012; 95% CI: 0.002-0.090) and stable disease (hazard ratio: 0.063; 95% CI: 0.009-0.464) as well as a nonsignificant trend toward better overall survival compared with partial response (hazard ratio: 0.169; 95% CI: 0.023-1.252) regardless of cancer type, ICI regimen or ICI line. Conclusion: Patients who achieved CR had longer survival compared with patients who did not achieve CR.