Overall survival benefit of continuing immune checkpoint inhibitors treatment post dissociated response in patients with advanced lung cancer

Purpose Dissociated response (DR, reduction at baseline or increase < 20% in target lesions compared with nadir in the presence of new lesions) was observed in 20-34% of patients treated with immune checkpoint inhibitors (ICIs). DRs were defined as progression disease (PD) per response evaluation criteria in solid tumors (RECIST v1.1), while evaluation criteria related to immunotherapy incorporated the new lesions into the total tumor burden or conducted further evaluation after 4-8 weeks rather than declaring PD immediately. The main objective of this study is to compare survival between people who continuing initial ICIs treatment and those who switched to other anticancer therapy at the time of DR. Patients and methods 235 patients with advanced lung cancer (LC) treated with ICIs were evaluated. Propensity score matching (PSM) was used to minimize potential confounding factors. Post-DR OS, target lesion changes were evaluated. Results 52 patients had been estimated as DRs. After PSM, the continuing ICIs treatment Post-DR cohort still had a significantly longer median post-DR OS than discontinuing ICIs treatment Post-DR cohort, 10.63 months (95% CI 6.27-NA) versus 4.33 months (95% CI 1.77-NA), respectively (p = 0.016). Conclusion Within the limitations of this single-center retrospective analysis, clinically stable patients who were judged by clinicians to be eligible for continuing ICIs treatment post-DR derived apparent OS benefit than discontinuing counterpart.