Does HER2 status influence in the benefit of ramucirumab and paclitaxel as second line treatment of advanced gastro-esophageal adenocarcinoma? Data from the AGAMENON-SEOM registry

Purpose This study aimed to compare ramucirumab-paclitaxel versus chemotherapy in second-line (2L) advanced gastroesophageal cancer (aGEC) based on HER2 status and analyze prognostic factors. Methods The study includes patients from the AGAMENON-SEOM registry with aGEC and known HER2 status who received 2L between 2016 and 2021. The Kaplan-Meier method was used to calculate progression-free survival (PFS) and overall survival (OS) and multivariable Cox regression analysis was done to adjust for confounding variables. Results Of the 552 patients who met the selection criteria, 149 (26.9%) had HER2-positive aGEC, 89 were treated with chemotherapy, and 60 with ramucirumab-paclitaxel, and 403 had an HER2-negative aGEC, 259 were treated with chemotherapy, and 144 with ramucirumab-paclitaxel. In the whole sample, 2L PFS was 3.0 months (95% CI 2.8-3.2), 2L OS, 5.7 months (5.2-6.3), and ramucirumab-paclitaxel versus chemotherapy was associated with increased PFS (HR 0.64, 95% CI 0.53-0.78, p < 0.0001) and OS (HR 0.68, 0.55-0.83, p = 0.0002). Median PFS of ramucirumab- paclitaxel versus chemotherapy was 3.5 vs 2.8 months (HR 0.67, 0.54-0.83, p = 0.0004) in HER2-negative, and 4.7 vs 2.7 months (HR 0.57, 0.40-0.82, p = 0.0031) in HER2-positive aGEC, respectively. Median OS for ramucirumab-paclitaxel versus chemotherapy was 6.6 vs 5 months (HR 0.67, 0.53-0.85, p = 0.0007) in HER2-negative, and 7.4 vs 5.6 months (HR 0.70, 0.53-1.04, p = 0.083) in HER2-positive aGEC, respectively. ECOG-PS, tumor burden, Lauren subtype, and neutrophil-lymphocyte ratio were prognostic factors. Conclusions In patients with an aGEC from the AGAMENON-SEOM registry, 2L treatment with ramucirumab-paclitaxel was superior to chemotherapy in PFS, OS and response rate, independent of HER2 status.