The FDA rejected ITM Isotope Technologies Munich’s radiopharmaceutical candidate ITM-11 for neuroendocrine tumors due to manufacturing problems, according to the company. The decision delays a potential challenger expected to compete with Novartis’ approved therapy Lutathera. ITM said the agency cited manufacturing issues, but the rejection stops the path forward on a radiopharma program that previously reported patients with early-stage disease receiving ITM-11 lived for 23.9 months without tumor growth, compared with 14.1 months on everolimus in reported analysis. Manufacturing is a persistent gating item in radiopharmaceutical development because isotope supply, labeling consistency, and sterile processing must meet stringent controls—this rejection highlights how evidence and clinical promise can still be blocked by CMC execution.