Phase 3 Trial Comparing Disitamab Vedotin, Trastuzumab, and Tislelizumab Versus Chemotherapy with Trastuzumab With or Without Pembrolizumab for Advanced HER2-high Gastric or Gastroesophageal Junction Adenocarcinoma

What this Trial Is About

Researchers are evaluating the effectiveness and safety of combining Disitamab Vedotin, Trastuzumab, and Tislelizumab compared with chemotherapy combined with Trastuzumab, with or without Pembrolizumab, as a first treatment for advanced gastric or gastroesophageal junction adenocarcinoma that has high HER2 expression. This phase III randomized study focuses on patients who have not received prior systemic therapy for their advanced cancer or whose disease returned at least six months after previous treatment. The study aims to better understand treatment outcomes in this specific patient group. Participants will be randomly assigned to one of two treatment groups. One group will receive Disitamab Vedotin at 2.5 mgkg intravenously every two weeks along with Trastuzumab and Tislelizumab every three weeks until unacceptable side effects, disease progression, or other reasons for stopping treatment occur. The other group will receive chemotherapy with CAPOX oxaliplatin and capecitabine, Trastuzumab, and, if their PD-L1 expression is confirmed as CPS 1, Pembrolizumab every three weeks. Treatment continues under similar stopping conditions. During the study, participants will be regularly monitored for disease progression, overall survival, response rates, disease control, and duration of response using assessments by blinded central review committees and investigators for up to 24 months, with some outcomes tracked for up to five years. Patient-reported quality of life and adverse events will also be collected. The study includes follow-up visits and evaluations to assess safety and effectiveness over the course of the trial, which starts in 2026 and may continue through 2030.

A Study of Disitamab Vedotin Combined With Trastuzumab and Tislelizumab Versus Chemotherapy Combined With Trastuzumab With or Without Pembrolizumab in HER2-high Expression Advanced Gastric or Gastroesophageal Junction Adenocarcinoma.