Neoadjuvant combination of nivolumab plus ipilimumab achieved 59% pathological complete response (pCR) in MSI-high localized gastric and gastroesophageal junction (GEJ) adenocarcinoma.
Long-term follow-up (median 48.3 months) showed encouraging 4-year overall survival (OS) of 84.1% and event-free survival (EFS) of 83.5% in patients undergoing surgery.
The therapy was generally well tolerated with manageable grade 3/4 adverse events occurring in under 20% of patients during neoadjuvant and adjuvant phases.
These findings support exploration of organ-preserving strategies and randomized trials incorporating immunotherapy in this molecularly defined subgroup.
