LAUSR

e16020 Background: Docetaxel-based neoadjuvant chemotherapy has been suggested to be beneficial in patients with locally advanced gastric and gastro-oesophageal junction cancer (GC/GEJC). And immunotherapy also show promising treatment efficacy for advanced GC/GEJC. Here we compared the safety and efficacy of camrelizumab combined with chemotherapy versus chemotherapy alone as the neoadjuvant therapy for patients with resectable locally advanced GC/GEJC. Methods: Eligible patients diagnosed as resectable locally advanced GC/GEJC were randomized to receive neoadjuvant treatment, in arm A, the patients received FLOT alone (docetaxel 50 mg/m²; oxaliplatin 85 mg/m²; leucovorin 200 mg/m²; 5-FU 2600 mg/m², every 2 weeks), in arm B, the patients received FLOT combined with camrelizumab(camrelizumab 200mg intravenously every 3 weeks). Eligible patients underwent gastrectomy with D2 lymph node dissection. The primary end point of this trial was pCR rate and R0 resection rate, and the secondary end points were ORR,PFS, OS and safety profile. Results: From January 15 2020 to January 15 2021, 24 patients were recruited (11 patients in arm A and 13 patients in arm B). 19 patients had completed planned neoadjuvant treatment for 4 cycles (9 pts in the arm A, 10 ptsin the arm B). Two patients in the arm A were waiting for gastrectomy. This analysis was based on the 17 pts. In the arm A, the median age was 61 years (47-72 years) and a total of 5 males and 4 females, ECOG PS 0 (n = 1), ECOG PS 1 (n = 8). In the arm B, the median age was 63 years (57-71 years) and a total of 9 males and 1 females, all patients with ECOG PS 1. The R0 resection rate was high in arm B compared with arm A (10/10,100% vs. 5/7, 71.4%). No pCR were observed in the two arms. Tumour regression grade were as follows:TRG1 [arm A 0% (0/7), arm B 10% (1/10)], TRG2 [arm A 43% (3/7), arm B 60% (6/10)], TRG3 [arm A 29% (2/7), arm B 30% (3/10)].There was a significantly higher proportion of patients achieved a postoperative ypN0 in the arm B than arm A(60% vs 0%), which had preoperative clinical stage cT3-4N+M0. Postoperative pathologic staging was as follows: ypT1 [arm A 14% (1/7); armB 30% (3/10)]. ypT2 [armA 0% (0/7); armB 30% (3/10)]. ypT3 [arm A 29% (2/7); arm B 20% (2/10)]. ypT4 [armA 29% (2/7); armB 20% (2/10)]. Neither serious intraoperative complications nor immune-related adverse events were observed during perioperation. Treatment-related AEs neutropenia and leukopenia were manageable and there was no treatment-related death. Conclusions: Camrelizumab combined with FLOT showed promising efficacy as neoadjuvant treatment for patients with locally advanced gastric or GEJ adenocarcinoma, with low complications and acceptable toxicity. Clinical trial information: ChiCTR2000030610.