Neoadjuvant PD-1 inhibitor and apatinib combined with S-1 plus oxaliplatin for locally advanced gastric cancer patients: a multicentered, prospective, cohort study

Purpose Programmed cell death protein 1 (PD-1) inhibitor and apatinib have been utilized in metastatic gastric cancer patients. The current study aimed to further investigate the efficacy and safety of neoadjuvant S-1 plus oxaliplatin combined with PD-1 inhibitor and apatinib (SOXPA) in locally advanced gastric cancer (LAGC) patients. Methods This two-centered, prospective, cohort study analyzed 30 resectable LAGC patients receiving SOXPA as neoadjuvant therapy. Results Two (6.7%), 18 (60.0%), and 10 (33.3%) patients achieved complete response (CR), partial response (PR), and stable disease (SD), separately. The objective response rate (ORR) and disease control rate (DCR) were 66.7% and 100.0%, respectively. The R0 resection rate was 93.3%. Beyond that, 6 (20.0%), 18 (60.0%), and 6 (20.0%) patients achieved grade 1, 2, and 3 pathological responses. The pathological complete response (pCR) rate was 20%. The 1-year and 2-year disease-free survival (DFS) rates were 96.6% and 77.7% respectively; meanwhile, the 1-year and 2-year overall survival (OS) rates were 96.6% and 90.1%, separately. What's more, better clinical response (P = 0.046); achievement of ORR (P = 0.014), and better pathological response (P = 0.020) were correlated with longer DFS. Besides, ORR achievement was linked with longer OS (P = 0.040). Most adverse events were relatively mild and manageable. Grade 3 adverse events included leukopenia, anemia, neutropenia, fatigue, hand-foot syndrome, nausea and vomiting. No grade 4 adverse events were witnessed. Conclusion SOXPA as neoadjuvant therapy achieves a satisfying clinical response, pathological response, survival profile, and tolerable safety in LAGC patients.