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 1:1 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.

Glycosylation of the Fc region of IgG has a profound impact on the safety and clinical efficacy of therapeutic antibodies. While the biantennary complex-type oligosaccharide attached to Asn297 of the Fc is essential for antibody effector functions, fucose and outer-arm sugars attached to the core heptasaccharide that generate structural heterogeneity (glycoforms) exhibit unique biological activities. Hence, efficient and quantitative glycan analysis techniques have been increasingly important for the development and quality control of therapeutic antibodies, and glycan profiles of the Fc are recognized as critical quality attributes. In the past decade our understanding of the influence of glycosylation on the structure/function of IgG-Fc has grown rapidly through X-ray crystallographic and nuclear magnetic resonance studies, which provides possibilities for the design of novel antibody therapeutics. Furthermore, the chemoenzymatic glycoengineering approach using endoglycosidase-based glycosynthases may facilitate the development of homogeneous IgG glycoforms with desirable functionality as next-generation therapeutic antibodies. Thus, the Fc glycans are fertile ground for the improvement of the safety, functionality, and efficacy of therapeutic IgG antibodies in the era of precision medicine.
Animals ; Antibodies, Monoclonal ; adverse effects ; pharmacokinetics ; therapeutic use ; Glycosylation ; Humans ; Immunoglobulin G ; chemistry ; metabolism ; Protein Engineering ; methods ; Receptors, Fc ; chemistry ; metabolism ; Treatment Outcome