NEW YORK – Astellas Pharma on Monday said the Center for Drug Evaluation within China's National Medical Products Administration has accepted its biologics license application seeking approval for the IgG1 monoclonal antibody zolbetuximab as a first-line treatment for CLDN18.2-positive advanced gastric cancer.
Zolbetuximab is designed to bind to the transmembrane protein CLDN18.2 on the surface of gastric epithelial cells. Astellas is seeking approval for the agent as a first-line treatment for patients with locally advanced, unresectable or metastatic HER2-negative gastric or gastroesophageal junction adenocarcinoma whose tumors are CLDN18.2-positive.
In its application to the NMPA, Tokyo-based Astellas submitted data from the Phase III GLOW and SPOTLIGHT trials, in which investigators compared the activity of zolbetuximab plus different chemotherapies to chemo alone. Researchers reported a median progression-free survival of 8.2 months on the zolbetuximab-chemotherapy combination versus 6.8 months with just chemo. After one year, 35 percent of patients who received zolbetuximab-chemo were alive without their cancer progressing versus 19 percent in the comparator arm; two-year progression-free survival rates were 14 percent versus 7 percent, respectively.
In mainland China, 145 patients were randomized in the GLOW trial, and 36 patients were randomized in the SPOTLIGHT trial. In GLOW and SPOTLIGHT, 38 percent of screened patients were CLDN18.2-positive, defined as moderate-to-strong staining via immunohistochemistry testing for CLDN18 on at least 75 percent of tumor cells.
The incidence of gastric cancer ranks third among all cancers in China with more than 478,000 newly diagnosed patients and more than 373,000 deaths in 2020.
Astellas is seeking approval in the US, Europe, and Japan for zolbetuximab in this same setting based on data from these studies. If approved in China, zolbetuximab would be the first CLDN18.2-targeted therapy available there for advanced gastric cancer patients.