SmarT cell combined with PD-1 blockade and SOX as first-line treatment for patients with advanced gastric/gastroesophageal junction adenocarcinoma.

e16082 Background: Although PD-1 blokade plus chemotherapy has achieved a preferable response rate for advanced advanced gastric/gastroesophageal junction adenocarcinoma (GC/GEJC), patient survival remains unsatisfactory. In this study, we evaluated the efficacy and safety of a combination treatment of SmarT cell combined with PD-1 blockade and SOX in patients with advanced GC/GEJC. Methods: In this study, we enrolled adults (≥18 years) with previously untreated, unresectable, non-HER2-positive GC/GEJC, regardless of PD-ligand 1 (PD-L1) expression. Patients were assigned to PD-1 mAb plus chemotherapy (Tegafur and oxaliplatin every 3 weeks), or PD-1 mAb plus chemotherapy. Results: The Overall response rates were 66% (33/50) and 52% (26/50) for SmarT cell plus PD-1 mAb as well as chemotherapy and PD-1 mAb plus chemotherapy. The disease controlled rates for both groups were 94% and 80.0%, respectively. The median follow-up for PFS was 207 days for PD-1 mAb plus chemotherapy. While the median PFS for SmarT group has not been reached. The most common any-grade treatment-related adverse events were nausea, elevated liver enzymes, and peripheral leukemia reduction across both groups. No new safety signals were identified. Conclusions: SmarT cell shows superior ORR along with PFS benefit and an acceptable safety profile, in combination with PD-1 mAb plus chemotherapy versus PD-1 mAb plus chemotherapy in previously untreated patients with advanced gastric or gastroesophageal junction adenocarcinoma. Clinical trial information: ChiCTR2200061306 .