Camrelizumab combined with FOLFOX as neoadjuvant therapy for resectable locally advanced gastric and gastroesophageal junction adenocarcinoma.

4536 Background: Neoadjuvant chemotherapy has been demonstrated to improve the pathological complete response(pCR) and 5-year survival rate of patients with locally advanced gastric and gastroesophageal junction adenocarcinoma (GC/GEJC). Immunotherapy has become a new promising treatment for advanced GC/GEJC. Therefore, we intended to evaluate the safety and efficacy of Camrelizumab (anti-PD-1 antibody) combined with FOLFOX as the neoadjuvant therapy for patients with locally advanced GC/GEJC. Methods: Eligiblepatients were locally advanced GC/GEJC with clinical stage≥T2 and/or positive lymphoglandula confirmed by endoscopic ultrasonography (EUS) and imaging. They received 4 cycles neoadjuvant therapy which including Camrelizumab(200mg ivgtt D1), FOLFOX(Oxaliplatin 85mg/m 2 ivgtt D1, 5-Fu 400mg/m 2 iv D1, LV 200mg/m 2 ivgtt D1, 5-Fu 2.4mg/m 2 CIV 46 hours) every 14 days. Imaging evaluation was performed in 2-4 weeks after neoadjuvant therapy. Patients without progression disease (PD) received D2 radical gastrectomy. The primary endpoint was pCR, the secondary endpoints were R0 resection rate and safety. Results: From July 24 2019 to January 31 2020, 16 patients were eligible. The median age was 57 years (29-72 years). A total of 11(69%) males and 5(31%) females, ECOG PS 0 (n=9, 56%), ECOG PS 1 (n=7, 44%). All the patients completed 4 cycles treatment and none of them was confirmed PD by image. One of the patients refused gastrectomy and withdraw from the study. The other 15 patients underwent operation. Unfortunately, intraperitoneal metastases were confirmed in 2 patients during operation. 13 patients received D2 radical gastrectomy and all of them experienced R0 resection. Among the 13 evaluable patients, 1 patient (8%) was observed pCR, 3 patients (23%) experienced TRG1, 10 patients (77%) achieved stage reduction. Notably, 8 patients (62%) had lymphonodus pCR. The grade 3-4 treatment-related AEs were neutropenia (n=3, 19%), leukopenia (n=2, 13%) and anorexia (n=1, 6%). No serious AEs resulted in termination of treatment. Either severe immune-related AEs or treatment-related death was not observed. Conclusions: Camrelizumab combined with FOLFOX as neoadjuvant regimen in patients with locally advanced GC/GEJC showed promising pCR with good tolerance. Clinical trial information: NCT03939962 . [Table: see text]