GEMSTONE-303
Trial question
What is the role of sugemalimab plus chemotherapy in patients with advanced gastric cancer?
Study design
Multi-center
Double blinded
RCT
Population
Characteristics of study participants
27.0% female
73.0% male
N = 479
479 patients (129 female, 350 male).
Inclusion criteria: adult patients with unresectable, locally advanced or metastatic gastric or GEJ adenocarcinoma.
Key exclusion criteria: positive HER2 status; prior systemic therapy; disease progression within 6 months of adjuvant or neoadjuvant chemotherapy.
Interventions
N=241 sugemalimab plus chemotherapy (intravenous sugemalimab 1,200 mg every 3 weeks for up to 24 months with capecitabine plus oxaliplatin every 3 weeks for up to 6 cycles).
N=238 placebo plus chemotherapy (intravenous placebo every 3 weeks for up to 24 months with capecitabine plus oxaliplatin every 3 weeks for up to 6 cycles).
Primary outcome
Median overall survival
15.6 months
12.6 months
15.6 months
11.7 months
7.8 months
3.9 months
0.0 months
Sugemalimab plus
chemotherapy
Placebo plus
chemotherapy
Significant
increase ▲
Significant increase in median overall survival (15.6 months vs. 12.6 months; HR 1.33, 95% CI 1.09 to 1.64).
Secondary outcomes
Significant increase in median progression-free survival (7.6 months vs. 6.1 months; HR 1.52, 95% CI 1.23 to 1.85).
Significant increase in median overall survival in patients with anti-PD-L1 CPS ≥ 10 (17.8 months vs. 12.5 months; HR 1.56, 95% CI 1.18 to 2.08).
Significant increase in overall response in patients with anti-PD-L1 CPS ≥ 5 (68.6% vs. 52.7%; AD 15.9%, 95% CI 6.6 to 25.2).
Safety outcomes
No significant difference in treatment-related adverse events.
Conclusion
In adult patients with unresectable, locally advanced or metastatic gastric or GEJ adenocarcinoma, sugemalimab plus chemotherapy was superior to placebo plus chemotherapy with respect to median overall survival.
Reference
Xiaotian Zhang, Jufeng Wang, Gang Wang et al. First-Line Sugemalimab Plus Chemotherapy for Advanced Gastric Cancer: The GEMSTONE-303 Randomized Clinical Trial. JAMA. 2025 Apr 15;333(15):1305-1314.
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