Camrelizumab combined with FLOFOX as neoadjuvant therapy for resectable locally advanced gastric and gastroesophageal junction adenocarcinoma: Updated results of efficacy and safety.

4036 Background: Although anti-PD-1 antibody in combination with chemotherapy has shown promising antitumor activity in advanced gastric or gastroesophageal junction adenocarcinoma (GC/GEJC), the evidence of neoadjuvant therapy for locally advanced GC/GEJC is limited. Camrelizumab combined FOLFOX as neoadjuvant therapy for resectable locally advanced GC/GEJC was a prospective, single-arm, phase 2 study we conducted. Here, we updated the results of efficacy and safety of this study. Methods: Patients confirmed by endoscopic ultrasonography (EUS) and imaging with clinical stage≥T2 and/or positive lymph nodes were enrolled. They received 4 cycles of camrelizumab (200mg ivgtt on day1, q2w) plus FOLFOX (oxaliplatin 85mg/m 2 ivgtt, LV 200mg/m 2 ivgtt, 5-Fu 400mg/m 2 iv followed by 2.4mg/m 2 CIV 46 hours on day 1, q2w) as neoadjuvant therapy. Then patients without disease progression evaluated by imaging underwent gastrectomy of D2 lymph node dissection. The primary endpoint was pCR, the secondary endpoints were R0 resection rate and safety. Results: Between Jul 24 2019 and Nov 30 2020, 49 patients were enrolled. The median age was 57 years (29-72 years). All patients completed 4 cycles treatment. Unfortunately, 2 of them were confirmed PD by imaging. In addition, two patients refused gastrectomy and withdrew from the study. Eventually, 45 patients underwent gastrectomy, of which 3 patients had intraperitoneal metastases during the operation. A total of 42 patients were evaluable, all of them gained R0 resection (100%), 4 patients (10%) achieved pCR and 10 patients (24%) reached TRG1. Among the patients experienced pCR, one of them was Her-2 positive, one was MSI-H, the rest two of them were PD-L1-positive (CPS≥10). The most common ≥grade 3 adverse events (AEs) were neutropenia (35%) and leukopenia (16%). Only 1 patient (2%) experienced grade 3 immune-related AEs of alanine aminotransferase and aspartate aminotransferase increase. No serious AEs resulted in termination of treatment or death. Conclusions: Camrelizumab combined with FOLFOX was an effective and safe neoadjuvant therapy strategy for patients with resectable locally advanced GC/GEJC. Furthermore, the analysis of biomarkers with clinical benefits is undergoing. Clinical trial information: NCT03939962. [Table: see text]