FDA issued a complete response letter (CRL) to ITM Isotope Technologies Munich SE for its radiotherapeutic ITM-11 (177Lu-edotreotide) intended to treat gastroenteropancreatic neuroendocrine tumors (GEP-NETs). ITM-11 is built on 177Lu radiolabeled therapy, and the company said the CRL stemmed from manufacturing issues at a third-party facility. The FDA did not cite concerns with the data package or safety profile, according to the filing description. That leaves the next steps focused on resolving manufacturing and quality issues required for approval. For radiopharmaceutical developers, the update underscores how downstream facility performance and process controls can remain gating factors even when clinical data are otherwise acceptable. ITM now has to align with FDA manufacturing expectations to re-enter review.