Patients with HER2-positive advanced gastric cancer who have failed standard first-line and second-line therapies have limited treatment options. Disitamab vedotin, a novel anti-HER2 antibody-drug conjugate, has been approved in China for this patient population. Additionally, immune checkpoint inhibitors (ICIs) have become a cornerstone of treatment for advanced gastric cancer, but disease progression or immune-related adverse events often lead to treatment discontinuation, raising the clinical question of immunotherapy rechallenge. Preclinical and early clinical evidence suggests that disitamab vedotin may modulate the tumor immune microenvironment and synergize with PD-1 blockade. Furthermore, multimodality radiotherapy (MMRT), combining low-dose radiotherapy (LDRT) and stereotactic body radiotherapy (SBRT), may enhance systemic anti-tumor responses by releasing tumor antigens and remodeling the immune microenvironment. This prospective, single-center, multicenter, non-interventional study aims to evaluate the efficacy and safety of disitamab vedotin in combination with PD-1 inhibitor immunotherapy and multimodality radiotherapy in patients with HER2-positive advanced gastric cancer after failure of first- and second-line treatment. Eligible patients will receive disitamab vedotin and PD-1 inhibitor per standard clinical guidelines, followed by MMRT targeting at least two independent lesions. The primary endpoint is progression-free survival (PFS) assessed by RECIST v1.1. Secondary endpoints include overall survival (OS), objective response rate (ORR), disease control rate (DCR), and safety profile. Exploratory biomarker analyses will be conducted using tumor tissue and peripheral blood samples. A total of 30 patients will be enrolled. This study is conducted in compliance with the Declaration of Helsinki and relevant Chinese regulations, with approval from the West China Hospital Ethics Committee and written informed consent from all participants.
See this in plain English?
AI-rewrites the medical criteria so a patient or caregiver can understand them. Always confirm with the trial site.
progression-free survival (PFS)
Timeframe: From study enrollment until disease progression, death, or study completion (whichever occurs first); estimated follow-up duration is 12-24 months.
overall survival (OS)
Timeframe: From study enrollment until disease progression, death, or study completion (whichever occurs first); estimated follow-up duration is 12-24 months.
objective response rate (ORR)
Timeframe: From study enrollment until disease progression, death, or study completion (whichever occurs first); estimated follow-up duration is 12-24 months.