The final results of the Phase 3 COMPASSION-15 trial confirmed that cadonilimab, a bispecific PD-1/CTLA-4 antibody, combined with XELOX chemotherapy offers a significant long-term survival benefit for patients with advanced gastric or gastroesophageal junction (GEJ) adenocarcinoma compared to XELOX alone. After a median follow-up of 33.9 months, patients treated with cadonilimab plus XELOX achieved a median overall survival of 13.9 months versus 11.1 months in the control group, and a median progression-free survival of 7.0 months versus 5.3 months. The duration of response was nearly doubled, at 8.9 months versus 4.5 months.
Importantly, this improvement was observed across all PD-L1 expression levels, including patients with low PD-L1 (CPS ≤ 5), showing consistent benefits regardless of biomarker status. The combination also demonstrated a favorable and manageable safety profile, with no new long-term adverse effects identified. The most common Grade ≥3 treatment-related side effects were hematological, such as decreased platelet and neutrophil counts.
The findings further strengthen cadonilimab’s position as a new standard of care in the first-line treatment of advanced gastric and GEJ adenocarcinoma. Following these results, cadonilimab was approved in China in September 2024. Researchers believe the drug’s dual immune checkpoint targeting represents a meaningful step forward in improving outcomes for patients with these aggressive cancers.