There are two cohorts in this study. HER2-positive and HER2-low patients will be allocated to cohort 1 and cohort 2, respectively. When the 20th, 40th, or 60th patient in each cohort completed at least one post-baseline tumor assessment, the Safety Monitoring Committee will review the safety and efficacy of these patients to determine dose selection, enrollment continuation, study population, and sample size.
The objective of this study is to assess the safety, efficacy, pharmacokinetics, and immunogenicity of MRG002 as single agent in patients with HER2-positive /HER2-low locally advanced or metastatic gastric/ gastroesophageal junction cancer.