YANTAI, China, June 3, 2025 /PRNewswire/ -- On June 2 (Chicago time), in an oral presentation at the 2025 ASCO Annual Meeting, Dr. Lin Shen from Beijing Cancer Hospital presented the results of a Phase 2 clinical study conducted in China evaluating the efficacy and safety of disitamab vedotin (DV), developed by Remegen Co., Ltd., and toripalimab (PD-1) combined with CAPOX or trastuzumab as the first-line therapy for HER2-expressing patients with locally advanced or metastatic (la/m) gastric cancer. Comparing to the control group who received standard-of-care therapy, the DV combination therapy demonstrated clinically meaningful efficacy improvement, potentially to benefit patients who are non-responders to traditional targeted therapies.

The data presented are from the Phase 2 part of a randomized, multi-cohort, seamlessly connecting Phase 2/3 study, which enrolled systematic chemotherapy-native patients with different HER2 expression levels. As of April 7, 2025, the results showed:

• Among HER2-overexpressing gastric cancer patients, compared to the PD-1-trastuzumab-CAPOX combination therapy, DV and PD-1 + chemotherapy as well as DV and PD-1 + trastuzumab both demonstrated statistically significant efficacy and favorable safety profiles.

  • Objective response rate (ORR): 66.7% vs 82.4% vs 68.8%;

  • Median progression-free survival (mPFS): NR vs NR vs 14.1 months, with risk of disease progression decreasing by 54%（HR=0.46）and 41% (HR: 0.59);

  • 12-month PFS rate: 66.3%, 67% and 53.6%；

  • Common TRAEs of grade 3-5: diarrhea, neutrophil count decreased, platelet count decreased, etc.

• In patients with HER2-low-expressing gastric cancer, promising efficacy was observed with DV + PD-1 + CAPOX comparing to PD-1 + CAPOX, with a manageable safety profile.

  • ORR: 72.0% vs 47.8%;

  • mPFS: 9.9 vs 7.2 months, with risk of disease progression decreasing by 31% (HR: 0.69);

  • Common TRAEs of grade 3-5: diarrhea, neutrophil count decreased, platelet count decreased, etc.

• Dose optimization conducted in patients with HER2-median/low-expressing gastric cancer. Compared to PD-1 + CAPOX, DV at 2.5 mg/kg or 2.0 mg/kg combined with PD-1 + reduced-dose CAPOX showed significant efficacy, and better safety over the full-dose chemotherapy.

  • ORR: 71.4% vs 66.7% vs 56.3%;

  • 6-month PFS rate: 71.4%，72.7% and 53.3%.

Globally, this is the first study to explore the triple combination therapy of "HER2 ADC + PD-1 + targeted medication" as first-line treatment of patients with la/m gastric cancer, pioneering a new mode of synergistic therapy. The multi-cohort design of this study provides precision treatment regimen for gastric cancer patients with different level of HER2 expression. For the HER2-overexpressing gastric cancer patients, DV + PD-1 + trastuzumab has the potential to become the new standard first-line treatment; for the HER2-low-expressing gastric cancer patients, DV + PD-1 + chemotherapy has the potential to fill the treatment gap of these patients. Based on the data obtained from the phase 2 study, the phase 3 clinical study of the triple combination therapy in patients with HER2-median/low-expressing gastric cancer has been initiated in April, 2025, in which 616 participants were planned to be enrolled, to further validate the efficacy of the DV combination therapy.