Phase II Study of Platinum Re-administration in Non-small Cell Lung Cancer Following Chemoimmunotherapy Resistance.

Platinum compounds represent standard treatments for various cancers. However, the efficacy of re-administrating platinum compounds has been demonstrated only in ovarian cancer and small cell lung cancer (SCLC), with its utility in non-small cell lung cancer (NSCLC) remaining unclear. Given that the prognosis of NSCLC has improved with effective treatments such as immune checkpoint inhibitors (ICIs), we propose a multicenter, single-arm, prospective phase II trial of re-administrating platinum-based combination therapy for NSCLC. Patients with NSCLC who have progressed after chemoimmunotherapy and exhibit a platinum-free interval of 85 days or more will receive carboplatin combination therapy. The drugs combined with carboplatin - pemetrexed, nab-paclitaxel, or gemcitabine - must not have been administered previously. The primary endpoint is progression-free survival (PFS), assessed using the Response Evaluation Criteria in Solid Tumors (RECIST) version 1.1. Assuming a threshold PFS of 4.2 months and an expected hazard ratio of 0.60, the required sample size is calculated as 40 patients to achieve 70% power with a 5% alpha error. Secondary endpoints included objective response rate, toxicity, and overall survival. This study will clarify the efficacy of re-administrating platinum compounds to patients with NSCLC who have developed resistance to chemoimmunotherapy.