This study focuses on treating patients with gastric cancer (cancer of the stomach) that has spread to the lining of the abdomen, known as peritoneal metastases. The research compares two different treatment approaches: one combining standard therapy with a special way of giving paclitaxel directly into the abdominal cavity (called intraperitoneal administration), and another using only standard therapy. The standard therapy may include various medications such as fluorouracil, oxaliplatin, capecitabine, docetaxel, pembrolizumab, nivolumab, zolbetuximab, and trastuzumab.

The main purpose is to determine if adding intraperitoneal paclitaxel to standard treatment helps patients live longer. During the study, patients will be randomly assigned to receive either the combination of intraperitoneal paclitaxel with standard therapy or standard therapy alone. The treatment period may continue for up to 60 months, depending on how well patients respond to the therapy.

Throughout the study, doctors will monitor patients’ overall health, measure how well the treatment is working, and track any side effects that may occur. They will also assess patients’ quality of life during and after treatment using specialized questionnaires. Some patients may later become eligible for surgery if their condition improves significantly with treatment.