Astellas: CDMO issues cause FDA to reject gastric cancer mAb

Zolbetuximab is an investigational, chimeric IgG1 monoclonal antibody (mAb) that targets and binds to transmembrane protein claudin 18.2 (CLDN18.2). The drug is in trials for gastrointestinal adenocarcinomas and pancreatic tumors, but Astellas has hit a setback receiving a complete response letter from the US Food and Drug Administration (FDA).

“The FDA stated that the agency cannot approve the BLA [Biologics License Applications] by the Prescription Drug User Fee Act (PDUFA) action date of January 12, 2024, due to unresolved deficiencies following its pre-license inspection of a third-party manufacturing facility for zolbetuximab,” Astellas said in a statement.

“Astellas is working closely with the FDA and the third-party manufacturer to establish a timeline to quickly resolve the agency’s feedback. No other Astellas products are affected.”

The firm added the FDA has not raised any concerns related to the clinical data, including efficacy or safety of zolbetuximab, and is not requesting additional clinical studies.

The contract development and manufacturing organization (CDMO) in question has not been disclosed.

“We remain confident in zolbetuximab’s clinical profile and potential to fill a significant therapeutic gap for those diagnosed with advanced gastric or GEJ cancer whose tumors are CLDN18.2 positive,” said Moitreyee Chatterjee-Kishore, SVP and head of Immuno-Oncology Development at Astellas. “Astellas is committed to working with the FDA and the third-party manufacturer to address the agency’s feedback, and to bringing zolbetuximab to U.S. patients in need, as soon as possible.”