The landscape of immune therapy in vulnerable patients with advanced non-small cell lung cancer: a narrative review

Background and Objective: The clinical development of immune checkpoint inhibitors (ICIs) has led to substantial advances in the treatment of lung cancer. In particular, the contribution of ICIs to the longterm survival of certain patients with non-small cell lung cancer (NSCLC) has been reported. With the accumulated experience in the use of ICIs, numerous studies have documented the efficacy and safety of ICIs in patients with diverse backgrounds, including those with problematic indications for drug therapy. In the current review, we summarize the most recent literature-based findings on ICI administration in vulnerable patients with NSCLC and provide an overview of the current status and prospects of ICIs. Methods: Herein, we defined vulnerable as the group of patients with NSCLC and performance status (PS) 22 (poor PS), advanced age (275 years), or cancer cachexia. We conducted a narrative review of the literature on the efficacy and safety of ICIs in vulnerable patients with advanced NSCLC. Key Content and Findings: Among the vulnerable patient group, poor PS was a strong, poor prognostic factor, even in patients undergoing ICI therapy. ICI therapy in older patients can be effective, although adverse events (AEs) should be carefully monitored. The efficacy of ICI therapy in patients with cancer cachexia is poor, with further therapeutic development warranted. Conclusions: Although prior studies have evaluated lung cancer pharmacotherapy in various vulnerable populations, clinical studies on the application of ICIs in patients with vulnerable NSCLC are lacking in both number and quality. Further development of these therapeutic agents, with the emergence of additional evidence regarding their appropriate use in this population, is expected.