MO5-3 Nivolumab monotherapy in 3rd-line treatment for HER2 positive or negative advanced gastric cancer

Abstract

Trastuzumab deruxtecan (DS-8201) showed clinical benefit among HER2 positive (H+) advanced gastric cancer (AGC) patients who received at least two previous therapies. Subgroup analysis of ATTRACTION-2 trial showed that nivolumab was efficacious regardless of prior Trastuzumab use. Little is known about proper use of nivolumab, trifluridine/tipiracil, and DS-8201 in 3rd-line treatment. The purpose of this study is to compare nivolumab efficacy between H+ and HER2 negative (H-) AGC patients in clinical practice. We retrospectively reviewed the medical record of 38 AGC patients who received nivolumab monotherapy in 3rd-line treatment at our institution until August 2020. The baseline characteristics of H+ group (n=10)/ H- group (n=28) were as follows: median age, 71/69 years; male, 90%/68%; ECOG PS 0-1, 80%/79%; previous gastrectomy, 20%/29%; intestinal type, 60%/43%; liver meta, 50%/32%; and ascites, 40%/54%. All H+ patients had received trastuzumab. Among 6 in H+ group/ 16 in H- group who had measurable lesions, objective response rate was 33%/19%. Median progression-free survival and median overall survival were 3.5/1.8 months and 8.2/7.5 months, respectively. The frequencies of immune-related adverse events between two groups were similar (20%/14%). H+ was associated with better outcome of nivolumab monotherapy compared with H-, although this study was small sample size and single institutional retrospective analysis.