1224P Final analysis of clinical outcomes in the DELIVER trial: Observational study of nivolumab treatment in advanced gastric cancer (JACCRO GC-08)

Abstract

We conducted a prospective observational study to evaluate the real-world effectiveness of nivolumab (Nivo) monotherapy in previously treated advanced gastric cancer (GC) (Gastric Cancer 2021). Pre-planned 2-year final analysis was performed to confirm survival and tumor behavior of Nivo treatment. The DELIVER trial enrolled 501 patients (pts) with advanced gastric or GEJ adenocarcinoma treated with Nivo alone from Mar 2018 to Aug 2019 (UMIN000030850). Primary endpoint was overall survival (OS), secondary endpoints were response rate (RR), disease control rate, progression-free survival (PFS), tumor regression rate (TRR) / tumor progression rate (TPR) at 1st evaluation, tumor growth rate (TGR) which was calculated as a percentage increase in tumor volume during 1 month, and safety. 487 pts were evaluable (median age 70y [26-90], 71% male, ECOG PS0/1/2 42/44/14%, No. of prior regimen 1/2/≥3 2/39/59%, 42% pts with ascites). Median OS was 5.8 months (m) (95%CI 5.3-6.9) with 1y-survival rate of 30% and 2y-survival rate of 14%, and median PFS was 1.8 m (95%CI 1.7-2.0). The RR was 14.5% in 282 pts with measurable lesions. The sub-group analysis of OS by clinical factors was the following: male/female; 6.5/5.1m (p=0.001), PS0/1/2; 8.7/5.6/2.5m(p<0.001), tub/por or sig; 8.1/5.2m (p<0.001), albumin<3.5/≥3.5; 4.2/8.8m (p<0.001), and with/without peritoneal metastases; 4.9/8.4m (p<0.001). Median OS and PFS by tumor response (CR or PR/SD/PD) were 32.8/11.4/4.2m and 13.9/11.7/3.8/1.5m, respectively. In 147 elderly pts aged ≥75-y, RR, PFS, and OS were 14.3%, 2.0m, and 6.5m, respectively, and the safety profile was comparable to pts aged <75-y. Median TRR and TPR were 20.0% and 26.7%, in 75 pts with tumor regression and 185 pts with tumor progression, respectively. The TGR decreased from 3.8 to 2.8 after Nivo introduction. There were no associations between PFS/OS and tumor burden or TGR at baseline before Nivo. The final analysis confirmed the efficacy of Nivo for advanced GC pts in clinical practice, with comparable outcomes in the elderly pts. Nivo was effective regardless of tumor burden or TGR at pre-treatment in advanced GC.