The goal of this observational study is to learn about in describe treatment pattern and clinical outcomes in patients with HER2-overexpressed advanced solid tumors after progression of first-line standard therapy. The main questions it aims to answer are:

• To evaluate the real-world safety and efficacy of Disitamab Vedotin in second-line and beyond treatment of advanced solid tumors with HER2 overexpression
• To describe the treatment pattern and clinical outcomes of patients with advanced gastric cancer with HER2 overexpression in real world Settings after the failure of first-line standard therapy.

This is a prospective, non-interventional, multi-cohort, multi-center real-world study to evaluate the treatment pattern and clinical outcomes of patients with advanced HER2-overexpressed solid tumors after the progression of first-line standard therapy. Enrolled subjects in this study were treated according to the treatment protocol established by physicians according to clinical routine. The tests, examinations and drug use in the study were consistent with the requirements of the clinical practice. No additional tests, examinations and drugs were generated from the data collection in this study. The study included 306 patients with HER2-overexpressed advanced gastric/gastroesophageal junction (GEJ) adenocarcinoma and other advanced solid tumors who had failed previous first-line standard therapy. HER2 overexpression was defined as IHC2+ or IHC3+ detected by immunohistochemistry (IHC) (either primary or metastatic tumor tissue).

Inclusion Criteria:

• Signing informed consent and agreeing to comply with study requirements;
• Age ≥18 years old, gender unlimited;
• ECOG physical status 0-2 points;
• Patients with locally advanced or metastatic solid tumors confirmed histologically or cytologically;Cohort1-2 cohort: patients who had received at least previous first-line standard therapy (HER2 IHC3+ or IHC2+/FISH+ patients with first-line trastuzumab (or its biosimilar) combined with chemotherapy (fluorouracil and/or platinum-based chemotherapy);IHC2+/FISH- patients with first-line Immunotherapy combined with chemotherapy (fluorouracil and/or platinum-based chemotherapy) or chemotherapy alone);In Cohort3 cohort, patients received at least the standard first-line treatment clearly recommended by the guidelines. Patients with clear disease progression confirmed by the investigator or documented history.
• HER2 overexpression was defined as 2+ or 3+ immunohistochemistry (both primary and metastatic tumor tissue were acceptable), and previous patient test results (confirmed by the investigator) or center test results were acceptable.
• Have measurable or evaluable lesions according to RECIST1.1 criteria;
• The investigator evaluated that the patients would benefit from the study treatment;
• Good compliance, willing and able to follow the trial and follow-up procedures;
• Have traceable patient medical records.

Exclusion Criteria:

• Known hypersensitivity or delayed allergic reactions to certain components of the study drug or similar drugs;
• Participating in any interventional clinical trials;
• The investigator assessed inappropriate inclusion.

Patients with advanced solid tumors with HER2 overexpression after previous first-line standard therapy failure