Astellas Resubmits Claudin18.2 Antibody Marketing Authorization Application

Recently, the pharmaceutical company Astellas announced that the U.S. Food and Drug Administration (FDA) has confirmed the resubmission of the Biologics License Application (BLA) for their investigational monoclonal antibody zolbetuximab. Zolbetuximab targets Claudin (CLDN) 18.2 and is being developed for first-line treatment of CLDN18.2-positive, HER2-negative, locally advanced unresectable or metastatic gastric or gastroesophageal junction (GEJ) adenocarcinoma.

If approved, zolbetuximab would become the first and only targeted therapy option for the CLDN18.2-positive patient population in the United States. According to the Prescription Drug User Fee Act (PDUFA), the FDA has set a new target action date of November 9, 2024 for this application.

In the U.S., gastric cancer is estimated to have affected 26,890 people and caused 10,880 deaths in 2024. Early gastric cancer often presents with symptoms overlapping with more common benign gastric conditions, leading to diagnosis at later, metastatic stages. Patients with metastatic gastric cancer have a 5-year relative survival rate of only 7%.

The zolbetuximab BLA resubmission is based on results from the Phase 3 GLOW and SPOTLIGHT trials, which evaluated zolbetuximab in combination with chemotherapy regimens compared to placebo plus chemotherapy. Approximately 38% of enrolled patients in these trials were CLDN18.2-positive, defined as having moderate-to-strong membrane staining in ≥75% of tumor cells.

In March 2024, zolbetuximab was approved by Japan's Ministry of Health, Labor and Welfare (MHLW), making it the first and currently only approved targeted therapy for CLDN18.2-positive, unresectable, advanced or recurrent gastric cancer patients. Astellas has also submitted zolbetuximab marketing applications to regulatory authorities around the world, which are currently under review.