Updated overall survival data and predictive biomarkers of autologous NK cells plus Sintilimab as second-line treatment for advanced non-small cell lung cancer.

Purpose: Combination strategies involving immune checkpoint inhibitors (ICIs) have been a prominent focus of research in the treatment of non-small cell lung cancer (NSCLC). Our prior findings demonstrated that the combination of autologous NK cells with the PD-1 antibody (Sintilimab), offered promising efficacy in NSCLC patients who failed the first-line platinum-based chemotherapy. Here, we present updated overall survival (OS) data from the final analysis, aiming to identify patient subgroups that derive maximal benefit from this therapeutic approach. Methods: Twenty NSCLC patients without driver gene mutations were enrolled and treated with a combination of autologous NK cells and Sintilimab every three weeks. Multicolor immunofluorescence staining was applied to evaluate static markers within the tumor microenvironment. Concurrently, dynamic assessments were conducted using next-generation sequencing and monitoring of PD-1/PD-L1 expression on NK cells to identify patient populations with favorable prognoses. Results: The median OS was 27.3 months (95% CI, 0.76 to 53.8), with six patients still alive at the follow-up cutoff. A significant correlation was observed between the CD56+PD-L1+ cellular phenotype and extended survival. Clearance of circulating tumor DNA (ctDNA) and an increased percentage of PD-L1+ NK cells following treatment was associated with significantly better survival outcomes. Notably, prolonged treatment exposure did not lead to increased toxicity. Conclusion: The combination of autologous NK cells with Sintilimab significantly enhances long-term survival in NSCLC patients without exacerbating adverse effects, presenting a promising strategy for future combination immunotherapy approaches in NSCLC treatment. Clinical trial registration: https://www.clinicaltrials.gov/ct2/show/NCT03958097, identifier NCT03958097.