87 A new immunotherapy drug has demonstrated significant improvements in survival rates for patients with advanced gastric cancer, according to a clinical trial conducted in China. The GEMSTONE-303 trial assessed the effectiveness of sugemalimab, an anti-PD-L1 antibody, when combined with chemotherapy as a first-line treatment for patients with locally advanced or metastatic gastric or gastroesophageal junction adenocarcinoma. The findings were published in the journal JAMA. The study, which involved 479 patients, found that those receiving sugemalimab alongside capecitabine and oxaliplatin experienced a median overall survival of 15.6 months compared with 12.6 months in the placebo group. Progression-free survival, which measures the time before the disease worsens, was also significantly improved, with patients in the sugemalimab group achieving a median of 7.6 months compared with 6.1 months in the placebo group. Gastric cancer remains one of the most common and lethal cancers worldwide, with limited treatment options for advanced stages. The emergence of immunotherapy, particularly inhibitors targeting the PD-1 and PD-L1 pathways, has transformed treatment strategies in recent years. Sugemalimab works by blocking PD-L1, allowing the immune system to better detect and attack cancer cells. The trial enrolled patients with a combined positive score (CPS) of 5 or greater, indicating a significant presence of PD-L1 in their tumours. Previous studies have shown that patients with higher PD-L1 expression may respond more favourably to immunotherapy, and the results from GEMSTONE-303 reinforce this observation. Those with a CPS of 10 or greater saw even greater benefits, with median overall survival extending to 17.8 months compared with 12.5 months in the placebo group. Despite the encouraging survival improvements, treatment-related adverse events were observed in both groups. In the sugemalimab group, 53.9% of patients experienced grade 3 or higher adverse events, compared with 50.6% in the placebo group. Common side effects included reduced white blood cell counts, anaemia, and nausea. However, the study concluded that the safety profile of sugemalimab remained manageable and comparable to other PD-1 and PD-L1 inhibitors used in gastric cancer treatment. The results of GEMSTONE-303 provide strong evidence that sugemalimab could become a standard first-line treatment option for patients with advanced gastric or gastroesophageal junction cancer. Immunotherapy has already demonstrated significant benefits in other cancers, and its role in gastric cancer treatment continues to evolve. Researchers believe that further studies will help refine patient selection criteria and determine optimal combinations with other therapies. The findings come as the medical community continues to seek new approaches to improve survival outcomes for gastric cancer patients. With the incidence of this disease remaining high in East Asia and other regions, the introduction of more effective treatment options could have a meaningful impact on patient prognosis. The trial’s success adds to the growing body of evidence supporting the use of immunotherapy in the fight against one of the world’s most challenging cancers.