Named "CornerStone-003," this study is an early proof-of-concept study targeting patients with HER2-expressed gastric cancer who have completed standard adjuvant treatment. It is a randomized-control clinical trial designed to evaluate safety and immunologic efficacy of AST-301. Participants in the study will receive a total of three or six doses of AST-301 treatment. Aston Sci. will subsequently determine the optimal dosing schedule and analyze the correlation between immunogenicity and clinical efficacy by evaluating disease-free survival (DFS) as a secondary endpoint.

AST-301 is a DNA-based therapeutic cancer vaccine encoding the HER2 antigen. Aston Sci. is conducting separate clinical trials for breast cancer and gastric cancer as indications for AST-301. Currently, the CornerStone-001 study targeting breast cancer is underway in the United States, Australia, and Taiwan.

Gastric cancer, particularly HER2-expressed gastric cancer, has a high incidence rate in Asia, but there is a lack of studies specifically focused on this patient population. Effective adjuvant therapies to prevent recurrence after surgery are needed for high-risk patients, but there are limited treatment options. Therefore, the introduction of new therapies is urgently needed. Based on the observation that some gastric cancers respond to immune checkpoint inhibitors, Aston Sci. expects that novel immunotherapies like therapeutic cancer vaccines can contribute to improving patient survival.

Eunkyo Joung, CMO of Aston Sci., stated, "Through this clinical trial, we hope to demonstrate the potential of AST-301 as a new treatment option for HER2-expressed gastric cancer and play an important role in expanding the scope of immunotherapy for gastric cancer."