The US Food and Drug Administration (FDA) has declined to approve Astellas’s investigational gastric/gastroesophageal junction cancer drug, zolbetuximab, due to manufacturing issues. Zolbetuximab, a monoclonal antibody, was under priority review as the first specific agent for locally advanced unresectable or metastatic HER2-negative gastric or gastroesophageal junction adenocarcinoma that is claudin 18.2-positive. This overexpression in gastric cancer cells is linked to tumor growth and progression.
The FDA’s decision, which was due by January 12, 2024, was affected by “unresolved deficiencies” found during its pre-license inspection of a third-party manufacturing facility for zolbetuximab. Astellas is actively working with the FDA and the third-party manufacturer to resolve these issues promptly. The company also stated that the FDA is not requesting additional efficacy and safety data.
In phase 3 testing, zolbetuximab showed an improvement in median progression-free and overall survival by approximately 2-3 months compared to chemotherapy alone. If approved, pathologists will need to be proficient with claudin 18.2 testing as a companion diagnostic before zolbetuximab can be used, according to Mark Lewis, MD, a gastrointestinal oncologist at Intermountain Healthcare.
Zolbetuximab is also under review in Japan, Europe, and China. The article was written by M. Alexander Otto, a physician assistant with a master’s degree in medical science and a journalism degree, who is also an award-winning medical journalist and an MIT Knight Science Journalism fellow.