WASHINGTON — The U.S. Food and Drug Administration has rejected ITM Isotope Technologies Munich SE’s experimental radiopharmaceutical therapy ITM-11, citing manufacturing issues and matters involving a third-party commercial facility, the German biotechnology company said on Monday.
The decision came unexpectedly ahead of the FDA’s Aug. 28 target date for action on ITM-11, which was being developed to treat gastroenteropancreatic neuroendocrine tumors, or GEP-NETs. The therapy is designed to deliver radioactive lutetium-177 directly to tumors.
ITM said the FDA’s complete response letter identified manufacturing and third-party commercial facility-related issues. The company did not report concerns involving the clinical data package or the therapy’s safety profile.
ITM said it intends to address the issues and resubmit the application. Chief Executive Andrew Cavey said the company remained committed to working with the FDA on the matters identified in the letter.
The rejection interrupts plans for ITM-11 to potentially become a new competitor to Novartis’ Lutathera, an approved radioligand therapy also used to treat certain GEP-NETs.
ITM had entered the FDA review with encouraging late-stage clinical data. Its Phase 3 COMPETE trial found that patients receiving ITM-11 had a median progression-free survival of 23.9 months, compared with 14.1 months for those receiving everolimus, according to results reported by the company. The trial enrolled patients with Grade 1 or Grade 2, somatostatin receptor-positive GEP-NETs.
The company also reported a higher objective response rate with ITM-11 than with everolimus in the trial. Those findings were subsequently published in The Lancet.
Radiopharmaceuticals are a growing class of cancer treatments that combine a tumor-targeting molecule with a radioactive isotope, allowing radiation to be delivered more selectively to cancer cells. The FDA has issued specific guidance for the development and dosage optimization of oncology radiopharmaceuticals.
ITM had been preparing for a potential U.S. launch. In July, it created Lumara Bio as a dedicated oncology therapeutics division encompassing ITM-11 and other radiopharmaceutical candidates, saying commercial-readiness activities were under way.
The company’s application had been accepted by the FDA in November 2025, with an Aug. 28, 2026, Prescription Drug User Fee Act action date.
The FDA rejection means ITM-11 will not enter the U.S. market under the current application. ITM said it plans to work with regulators to resolve the identified manufacturing issues and resubmit the application.
