Exploratory Analysis of Patients With Gastric/Gastroesophageal Junction Adenocarcinoma With or Without Liver Metastasis From the Phase 3 RAINBOW Study

ABSTRACT

Purpose@#Liver metastasis (LM) is reported in approximately 40% of patients with advanced/ metastatic gastric/gastroesophageal junction adenocarcinoma (metastatic esophagogastric adenocarcinoma; mGEA) and is associated with a worse prognosis. This post-hoc analysis from the RAINBOW trial reported the efficacy, safety, and biomarker outcomes of ramucirumab and paclitaxel combination treatment (RAM+PAC) in patients with (LM+) and without (LM−) LM at baseline. @*Materials and Methods@#Patients (n=665) were randomly assigned on a 11 basis to receive either RAM+PAC (LM+ 150, LM− 180) or placebo and paclitaxel (PL+PAC) (LM+ 138, LM− 197). The overall survival (OS) and progression-free survival (PFS) were evaluated using stratified Kaplan–Meier and Cox regression models. The correlation of dichotomized biomarkers (VEGF-C, D; VEGFR-1,2) with efficacy in the LM+ versus LM− subgroups was analyzed using the Cox regression model with reported interaction P-values. @*Results@#The presence of LM was associated with earlier progression than those without LM, particularly in patients receiving PL+PAC (hazard ratio [HR], 1.68). RAM+PAC treatment improved OS and PFS irrespective of LM status but showed greater improvement in LM+ than that in LM− (OS HR, 0.71 [LM+] vs. 0.88 [LM−]; PFS HR, 0.47 [LM+] vs. 0.76 [LM−]).Treatment-emergent adverse events were similar between patients with and without LM. No predictive relationship was observed between biomarker levels (VEGF-C, D; VEGFR-1,2) and efficacy outcome (OS, PFS) (all interaction P-values >0.05). @*Conclusions@#RAM provided a significant benefit, irrespective of LM status; however, its effect was numerically stronger in patients with LM. Therefore, RAM+PAC is a clinically meaningful therapeutic option for patients with mGEA and LM.