Abstract 6410: An exosomal microRNA signature predicts the efficacy of ramucirumab plus paclitaxel in advanced gastric cancer: Findings from the prospective IVY trial
Authors: Shoda Katsutoshi , Xu Caiming , Asahii Yoh , Nagasaka Takeshi , Ichikawa Daisuke , Goel Ajay 
Published: March 2024

Abstract
Purpose: With rapid advances in the development of effective therapeutic regimens in patients with advanced gastric cancer, it is imperative to establish individualized treatment approaches that can help identify patient subsets that have the highest likelihood of response to a specific regimen. Although ramucirumab plus paclitaxel therapy is the standard second-line treatment for patients with advanced gastric cancer, biomarkers that can help predict therapeutic response are still lacking. This longitudinal study aimed to establish a liquid-biopsy assay that can predict response to ramucirumab plus paclitaxel therapy in patients with advanced gastric cancer.
Experimental Design: A prospective observational multicenter study (named the IVY study) enrolled 115 patients who received ramucirumab plus paclitaxel treatment. We collected serum specimens prior to the initiation of the treatment regimen. Patients were divided into responders and non-responders according to the response evaluation criteria in solid tumors (RECIST). We performed small RNA-sequencing (sRNA-Seq) in a subset of 28 patients with and without response to identify exosomal microRNA-based biomarkers that allowed risk stratification and response prediction in patients with advanced gastric cancer.
Results: The sRNA-Seq analysis and rigorous bioinformatic approaches using machine-learning algorithms allowed us to identify a panel of 10 exosomal microRNAs that robustly predicted resistance to ramucirumab plus paclitaxel treatment (AUC: 0.83). The panel of exosomal miRNAs was also shown to have a robust prognostic value for predicting survival outcomes in gastric cancer patients treated with ramucirumab plus paclitaxel, and Cox proportional hazards regression analysis showed that patients classified as high risk on the panel of exosomal miRNAs independent poor prognostic factor (OS: HR = 2.74, 95% CI = 1.56-4.81, P &lt; 0.01, RFS: HR = 1.84, 95% CI = 1.16-2.92, P &lt; 0.01). Following logistic regression and backward elimination, we trained a clinically feasible 5 exosomal miRNA signature by combining it with the Body Mass Index data, an independent clinical predictor (AUC: 0.84). We subsequently successfully validated the performance of this signature in the prospective clinical trial cohort (AUC: 0.87). Finally, we established a prognostic risk nomogram based on the circulating exosomal miRNA signature for a non-invasive and personalized pre-therapeutic selection approach.
Conclusions: We have developed a novel liquid biopsy-based assay that allows robust prediction of response to ramucirumab plus paclitaxel treatment in gastric cancer patients, and our assay provides a framework for a personalized medicine approach that can provide risk-based management and treatment for each patient prior to the initiation of therapy.
Citation Format: Katsutoshi Shoda, Caiming Xu, Yoh Asahii, Takeshi Nagasaka, Daisuke Ichikawa, Ajay Goel. An exosomal microRNA signature predicts the efficacy of ramucirumab plus paclitaxel in advanced gastric cancer: Findings from the prospective IVY trial [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 6410.