Gastric and Gastroesophageal Junction Cancer · Medical · Advanced / Metastatic · First-line HER2-negative advanced gastroesophageal adenocarcinoma

CheckMate 649

Clinical question: In first-line her2-negative advanced gastroesophageal adenocarcinoma, does the investigational strategy improve clinically meaningful outcomes versus its control?

Registry: NCT02872116 · One underlying study; aliases and follow-up publications consolidated.

Open-label phase III RCT; 1,581 patients randomized 1:1. Evidence cut-off: 13 November 2026.

Design, population and eligibility

Design / sample size

Open-label phase III RCT; 1,581 patients randomized 1:1.

Eligibility

Previously untreated unresectable advanced/metastatic non-HER2-positive gastric, GEJ or oesophageal adenocarcinoma; primary efficacy population PD-L1 CPS ≥5.

Intervention

Nivolumab + fluoropyrimidine/oxaliplatin chemotherapy versus chemotherapy.

Nivolumab 360 mg every 3 weeks with CAPOX or 240 mg every 2 weeks with FOLFOX, according to protocol, plus chemotherapy.

Comparator

chemotherapy.

Primary endpoint: Co-primary OS and PFS in PD-L1 CPS ≥5.

Key efficacy outcomes

At 5-year follow-up (minimum 60.1 months), CPS ≥5 OS HR 0.71 (95% CI 0.61–0.81) and PFS HR 0.71 (0.61–0.82). Five-year OS 16% vs 6%; five-year PFS 10% vs 6%; ORR 58% vs 46%.

Reported outcome

16%

Comparator: 6%. The bars are a simple display of the first reported pair only; consult the endpoint and time horizon above.

Safety and treatment delivery

Grade 3/4 treatment-related AEs 60% vs 45%; no new safety signal at 5 years. Initial reports showed more treatment discontinuation with nivolumab combination.

Clinical interpretation and limitations

Durable survival advantage, strongest in PD-L1-enriched groups. The five-year absolute survival landmark difference is 10 percentage points in CPS ≥5. Toxicity, immune contraindications and CPS context matter; this trial includes oesophageal adenocarcinoma as well as gastric/GEJ.

Interpret the reported hazard ratios in the context of the prespecified endpoint, statistical hierarchy, follow-up maturity, crossover/subsequent therapy and enrolled population. Median survival differences are not risk differences and must not be converted into NNT.

Absolute effect

No NNT/NNH is displayed unless an absolute event-risk difference at a clearly stated fixed timepoint can be calculated from reported trial data. Median survival differences and hazard ratios alone do not support an NNT. The visual above uses reported outcome data only.

Primary publication and follow-up

Primary publication

Registry / follow-up / authoritative source

Source-level verification status: primary publication identified and key quoted outcomes transcribed; where full-text toxicity or procedural details were not available, the page explicitly flags the limitation rather than inferring values.

Current-practice context · 13 November 2026

This page separates historical trial results from contemporary practice. Verify the applicable jurisdictional guideline, regulatory approval, biomarker assay, liver function, comorbidity and treatment availability before applying the evidence. NCCN Guidelines Insights are not a substitute for the full NCCN guideline.

Guideline/regulatory reconciliation and browser-rendered QA remain scheduled for the subsequent quality-control pass.