Real-World Effectiveness and Safety of Ramucirumab as a Second-Line Treatment for Patients with Unresectable Advanced or Metastatic Gastric/Gastroesophageal Junction Adenocarcinoma in Japan and South Korea: A Systematic Literature Review

INTRODUCTION

Gastric cancer has the highest incidence and mortality in Eastern Asia. The efficacy and safety of ramucirumab (RAM) monotherapy or in combination with paclitaxel (PTX) for patients with unresectable advanced or metastatic gastric/gastroesophageal junction adenocarcinoma (G/GEA) have been established in clinical trials. To assess the effectiveness and safety of RAM or RAM-based therapy as a second-line treatment in real-world clinical practice in Eastern Asia and to pave the way for future research, a systematic literature review (SLR) was conducted.

METHODS

Studies published between January 2014 and December 2021 were identified in PubMed, Embase, Cochrane Library, CNKI, Wanfang, and CBM databases.

RESULTS

This SLR included 23 studies from Japan and South Korea, of which 22 were retrospective and 11 were full-text articles. Most studies investigated RAM + PTX (range of median overall survival [mOS] 7.4-12.2 months; median progression-free survival [mPFS] 3.35-7.0 months). Data were limited for RAM, RAM + albumin-bound paclitaxel, and RAM + taxane. RAM + PTX was associated with longer survival (mOS 9.3-12.2 months vs. 5.2-9.7 months; mPFS 4.1-5.1 months vs. 3.0-4.1 months) than PTX. Patients with prior anti-programmed cell death 1 (anti-PD-1) exposure experienced longer mPFS (4.8 vs. 3.4 months) from RAM + taxane than those without prior anti-PD-1 exposure. Few patients (3.3-6.3%) discontinued RAM or RAM-based therapy because of adverse events (AEs). Hematological toxicities were most frequently occurring AEs and no new safety signals were identified compared to clinical trials.

CONCLUSION

RAM + PTX as a second-line treatment is effective and associated with an acceptable toxicity profile in patients with advanced or metastatic G/GEA in real-world settings of Japan and South Korea. More studies are recommended to further evaluate effectiveness and safety of RAM or RAM-based therapy, especially after anti-PD-1 therapy, in a wider Eastern Asian population.

TRIAL REGISTRATION

INPLASY registration number INPLASY2022120023.

Anti-PD-1 plus anti-angiogenesis combined with chemotherapy in patients with HER2-negative advanced or metastatic gastric cancer: a multi-institutional retrospective study

Background

Immunotherapy plus chemotherapy have been confirmed to be effective in treating advanced or metastatic gastric cancer (GC). Anti- programmed death-1 (PD-1) plus antiangiogenic agents have shown promising activity and tolerant toxicity in subsequent therapy of late-stage gastric cancer. The aim of this study was to assess the efficacy and safety of anti-PD-1 plus anti-angiogenic agents and chemotherapy in advanced or metastatic GC and to explore the potential biomarkers associated with response.

Methods

We retrospectively reviewed thirty human epidermal growth factor receptor 2 (HER2)-negative advanced or metastatic GC patients who received PD-1 plus anti-angiogenic drugs and chemotherapy. Conversion therapy was defined when the patients could undergo resection post combination therapy. Clinical data were retrieved from medical records. We conducted exploratory biomarker analysis of baseline gene mutations and tumor mutation burden (TMB) using the next-generation sequencing (NGS), PD-L1 by immunohistochemistry (IHC), and the tumor immune microenvironment (TIME) by multiplex immunofluorescence.

Results

A total of 30 patients received anti-PD-1plus anti-angiogenic drugs and chemotherapy during the study period. The objective response rate (ORR) was 76.7% [95% confidence interval (CI): 57.7-90.1%] and disease control rate (DCR) was 86.7% (95% CI: 69.3-96.2%). A total of 11 patients (36.7%) achieved conversion therapy and underwent surgery. The R0 resection rate was 90.9%. Of the 11 patients, 9 (81.8%) responded to the treatment, 1 with a pathological complete response (pCR) and 8 with a major pathological response (MPR). No adverse events of grade 3 or higher occurred. Neither PD-L1 expression nor TMB was significantly correlated with treatment response. Analysis of TIME revealed that the fraction of CD8⁺ T cell in the invasive margin was higher in responders than non-responders before treatment. TAM2 in the tumor center and CD8⁺ T cell in the invasive margin was significantly increased after combination therapy, which suggested that combination therapy promoted infiltration of CD8⁺ T cells, thereby exerting an antitumor effect.

Conclusions

Immunotherapy plus anti-angiogenic drugs and chemotherapy is a promising treatment strategy for advanced or metastatic GC patients. Tumor infiltration CD8⁺ T cells may serve as potential predictive biomarker.