Modeling analysis of RATIONALE-305: Impact of peritoneal metastasis (PM) representation on clinical outcomes in patients (pts) treated with tislelizumab plus chemotherapy (TIS+CT) with gastric cancer/gastroesophageal junction cancer (GC/GEJC).
Abstract
378 Background: RATIONALE-305 (NCT03777657) enrolled the highest number of pts with PM among similar trials and stratified pts with advanced GC/GEJC by presence of PM. We used statistical modeling to evaluate the impact of varying PM levels on outcomes with TIS+CT. Methods: We randomized adults with GC/GEJC (1:1) to TIS or placebo (PBO) + CT. Primary endpoints: OS in intent-to-treat (ITT) population and pts with programmed death-ligand 1 (PD-L1) Tumor Area Positivity (TAP) score ≥5%. We weighted pts using the method of moments to match a hypothetical population to ITT, with the same distribution of sex, primary tumor location, PD-L1 (TAP score
Fields of Study & Subjects
Gastric Cancer Management and Outcomes
Intraperitoneal and Appendiceal Malignancies
Cancer Immunotherapy and Biomarkers
Publication details
- Journal / source
- Journal of Clinical Oncology
- Publisher
- American Society of Clinical Oncology (ASCO)
- Volume
- 44
- Issue
- 2_suppl
- Pages
- 378–378
- Publication date
- 10 January 2026
- Language
- EN