Examining the Efficacy of Nivolumab for Gastric Cancer Focusing on Using an Inflammation-based Prognostic Score: A Multicenter Retrospective Study.

Abstract

To discover the positive therapeutic effects of nivolumab in patients with advanced gastric cancer (AGC), it is necessary to establish a useful biomarker to predict therapeutic efficacy. This multicenter retrospective study sought to evaluate the predictive impact of inflammation-based prognostic score (IBPS) on the therapeutic efficacy of nivolumab in patients with AGC. In this retrospective study, we evaluated 58 AGC patients treated with nivolumab from October 2017 to November 2018 at five institutes. Patients were categorized follows: progressive disease (PD) or disease control (DC). Blood chemistry tests were performed immediately before and after two courses of nivolumab; the correlation between best overall response and IBPS was investigated. Transition of each blood serum marker was also assessed. Of 58 patients, 37 (63.8%) were in the PD group and 21 (36.2%) in the DC group. No positive correlation was noted between IBPS and therapeutic efficacy of nivolumab both immediately before and after two courses of nivolumab. However, the neutrophil-lymphocyte ratio (NLR) (p=0.045) and prognostic index (PI) (p=0.0042) before nivolumab and NLR (p=0.025), PI (p=0.0030) and Glasgow prognostic score (GPS) (p=0.043) after nivolumab were significantly correlated with treatment sensitivity. Furthermore, a decrease in PNI was an independent prognostic factor to predict nivolumab resistance on univariate analyses (p=0.0051). Although no association between IBPS and therapeutic sensitivity was found, it is important to focus on the transition of PNI to predict therapeutic efficacy of nivolumab.