Retrospective analysis for efficacy and safety of nivolumab in advanced gastric cancer patients with malignant ascites

Abstract

Abstract Background Nivolumab is a standard of care as third line therapy for advanced gastric cancer. However, we have still few data about efficacy and safety of nivolumab for patients with malignant ascites. Methods We conducted a single institute retrospective study to evaluate the efficacy and safety of nivolumab alone for advanced gastric cancer with malignant ascites. We reviewed medical records of patients who received nivolumab as later-line for advanced gastric cancer from October 2017 to February 2019. High ascites burden (HAB) was defined as moderate or massive ascites. Low ascites burden (LAB) was defined as none or a little amount of localized ascites only at pelvic and/or liver surface. The efficacy and safety data were compared between these two groups. Tumor responses were assessed with RECIST and/or change of ascites volume. Results There were 13 patients with HAB and 17 patients with LAB treated with nivolumab. The HAB group was significantly younger (59 vs 65 years, p\u2009=\u20090.03), and had less prior gastrectomy (31 vs 71%, p\u2009=\u20090.04) and poorer performance status (PS 0; 8% vs 59%, p\u2009=\u20090.01), compared to LAB. Disease control rate was 31% (4/13) in the HAB group and 24% (4/17) in the LAB group (p\u2009=\u20090.70). The proportion of subsequent chemotherapy was similar to each group (10/13 vs 9/17, p\u2009=\u20090.26). The median follow-up time was 12 months. The median PFS was 1.0 and 1.5 months (p\u2009=\u20090.94) in the HAB and LAB groups, respectively. The median OS was 2.5 and 11.5 months (p\u2009=\u20090.10) in the HAB and LAB groups, respectively. In the HAB group, 4 patients with stable disease or better response showed durable PFS of 2+ to 10+ months, and all survived at the analysis. Immune-related adverse events occurred in 31% of the HAB group and 12% of the LAB group (p\u2009=\u20090.36), including one grade 3 event in each group. Conclusion Nivolumab was effective in some patients with HAB as well as LAB, and also tolerable in patients with HAB.