Allogeneic NK Cell Therapy Combined With Standard Maintenance Treatment in Advanced Solid Tumors

This study is designed as a prospective cohort study to evaluate the safety and efficacy of allogeneic NK cell injection combined with standard maintenance therapy in advanced solid tumor patients. Study Design: Cohort 1: Advanced non-squamous non-small cell lung cancer (NSCLC) without driver gene mutations, receiving NK cells + PD-(L)1 inhibitor + pemetrexed as first-line maintenance therapy (3-week cycles) Cohort 2: Advanced colorectal adenocarcinoma, receiving NK cells + cetuximab/bevacizumab + capecitabine as first-line maintenance therapy (2-week cycles) Cohort 3: Lymphodepletion exploration cohort for advanced non-squamous NSCLC, receiving fludarabine + cyclophosphamide preconditioning followed by NK cells + PD-(L)1 inhibitor + pemetrexed (3-week cycles) Each cohort includes a safety lead-in phase (3 patients) followed by an expansion phase (3-6 patients). Dose-limiting toxicity (DLT) will be assessed during the first cycle. Cohort 4 :advanced HCC with NK cells + VEGF + PD-(L)1 (3-week cycles). Cohort 5 :advanced GC with NK cells + PD-(L)1 + S-1 (2-week cycles).