A Study of CS1001 in Subjects With Gastric Adenocarcinoma or Gastro-Esophageal Junction Adenocarcinoma

Phase 3 Completed 479 enrolled CStone Pharmaceuticals

RandomizedParallel-groupQuadruple-blindTreatment

Summary

This is a phase III, multi-Center, randomized, placebo-controlled trial to investigate the efficacy and safety of CS1001 in combination with Oxaliplatin and Capecitabine (CAPOX) chemotherapy in first-line subjects with unresectable locally advanced or metastatic gastric adenocarcinoma (GC) or gastro-esophageal junction (GEJ) adenocarcinoma.

Timeline

Start: 2019-03-28
Primary completion: 2023-07-09
Completion: 2023-09-22

Outcome

Met primary endpoint

paper The sugemalimab group demonstrated significant improvements in overall survival PMID 39992668 ↗

paper and progression-free survival (median, 7.6 months [95% CI, 6.4-7.9] vs 6.1 months [95% CI, 5.1-6.4]; hazard ratio, 0.66 [95% CI, 0.54-0.81]; P < .001). PMID 39992668 ↗

Publications

Zhang X, Wang J, Wang G, Zhang Y, Fan Q, Lu C, Hu C, Sun M, Wan Y, Sun S, Wang J, Zhang L, Shu Y, Luo J, Zhu D, Shen Z, Yao S, Shi Q, Yang J, Shen L; GEMSTONE-303 Investigators. First-Line Sugemalimab Plus Chemotherapy for Advanced Gastric Cancer: The GEMSTONE-303 Randomized Clinical Trial. JAMA. 2025 Apr 15;333(15):1305-1314. doi: 10.1001/jama.2024.28463.

Drugs

Evaluation	Drug	Modality	Dose	Route
Subject	Sugemalimab	Monoclonal antibody	1200 mg	Intravenous
Background	Capecitabine	Small molecule	—	Oral
Background	Oxaliplatin	Small molecule	—	Intravenous