Treatment rationale and protocol design: an investigator-initiated phase II study of combination treatment of nivolumab and TM5614, a PAI-1 inhibitor for previously treated patients with non-small cell lung cancer

Background: There is no established standard 3^rd line treatment for patients with advanced non-small cell lung cancer (NSCLC). Although cytotoxic chemotherapeutic agents that are not used as 1^st or 2^nd line treatment are administrated as 3^rd line treatment, their anti-tumor efficacy is insufficient. Anti-programmed death ligand-1 (PD-L1)/programmed death-1 (PD1) treatment is more effective and less toxic than chemotherapy in anti-PD-L1/PD-1 treatment-naïve patients with NSCLC. Therefore, anti-PD-L1/ PD-1 therapy is considered an appropriate 3^rd line treatment. However, the anti-tumor efficacy is limited in patients previously treated with anti-PD-L1/PD-1 antibody. Today, new drugs are needed to increase the efficacy of anti-PD-L1/PD-1 antibodies. Methods: This open-label, single-arm, investigator-initiated phase II study is designed to evaluate combination treatment of nivolumab and TM5614, a plasminogen activator inhibitor (PAI-1) inhibitor as 3^rd or more line treatment in NSCLC patients who underwent standard treatment. The primary endpoint is the objective response rate and the secondary endpoints are progression-free survival (PFS), overall survival (OS), duration of response (DOR) and safety. Recruitment began in September 2023 and is expected to continue for approximately three years. Discussion: Currently, there is no standard 3^rd line treatment for advanced NSCLC, and we hope that the findings of this study will facilitate more effective treatments in this setting. Ethics and dissemination: the study protocol conformed to the ethical principles outlined in the Declaration of Helsinki. All patients will provide written informed consent prior to enrollment. Results will be published in a peer-reviewed publication. Trial Registration: This study is registered to Japan Registry of Clinical Trials with number: jRCT2061230039 (19/July/2023).