The most common adverse event was anemia (89.5%), and eight patients suffered severe toxicities of grade ≥3.<h4>Conclusions</h4>Disitamab vedotin exhibited encouraging anti-tumor effectiveness with a tolerable safety profile for advanced GC/GEJC patients with HER2 overexpression who had failed at least one line of systemic therapy in a real-world setting. Here, ERBB2 is linked to anemia (phenotype).