ITM reports re-treatment and dosimetry data for ITM-11 at ASTRO
ITM Isotope Technologies Munich and its oncology division Lumara Bio have presented two new datasets for 177Lu-edotreotide (ITM-11) in gastroenteropancreatic neuroendocrine tumours (GEP-NETs) at the ASTRO 2026 Annual Meeting in Boston. The findings, released on 27 September, cover real-world re-treatment outcomes from the SwissNET registry and dosimetry sub-study results from the Phase 3 COMPETE trial.
The registry analysis, led by Dr Julia Fricke of University Hospital Basel, examined 49 adults with metastatic, well-differentiated, somatostatin receptor-positive NETs who had previously completed a course of 177Lu-edotreotide and subsequently progressed. Of those, 37 were re-treated with the same radiopharmaceutical and 12 received a non-radiopharmaceutical systemic therapy. Patients in the re-treatment group recorded a median real-world progression-free survival of 12.5 months, against 4.8 months in the comparator group (p less than 0.001). Median overall survival reached 90.1 months versus 39.8 months in favour of re-treatment (p less than 0.001). ITM describes the analysis as the first real-world re-treatment dataset for the agent; the retrospective, registry-based design and small cohort size mean the findings are hypothesis-generating rather than confirmatory.
Dosimetry results from COMPETE
The second poster, presented by Dr Amir Iravani of UCLA, detailed dosimetry data from Substudy A of the COMPETE trial across 17 patients and 17 tumour lesions in 9 patients. Kidney absorbed dose coefficients showed low intra-patient variability, with a median of 14%, a finding the company says could support individualised dosing strategies based on Cycle 1 measurements. Tumour-to-kidney absorbed dose ratios remained above 1 across all treatment cycles, suggesting that radiation delivery to lesions consistently exceeded exposure to healthy renal tissue. The COMPETE trial itself previously met its primary endpoint, with ITM-11 demonstrating statistically significant improvement in progression-free survival compared to everolimus in Grade 1 and Grade 2 GEP-NETs.
Dr Celine Wilke, chief medical officer of ITM, said the datasets "provide signals that radiopharmaceutical therapy represents an approach worth investigating in settings in which it has not yet been studied."
Market and regulatory context
177Lu-edotreotide remains an investigational product with no regulatory approval in any jurisdiction. Its closest approved comparator is 177Lu-DOTATATE (Lutathera, Advanced Accelerator Applications, a Novartis company), which received FDA approval in 2018 for somatostatin receptor-positive GEP-NETs. ITM is seeking to differentiate ITM-11 on the basis of its non-carrier-added production process, which the company argues delivers a higher specific activity product. A second Phase 3 study, COMPOSE, is evaluating ITM-11 in more aggressive Grade 2 and Grade 3 GEP-NETs, a population with fewer established treatment options and a setting where Lutathera's label does not extend.
The radiopharmaceutical therapeutics sector is expanding rapidly, with multiple companies pursuing lutetium-labelled and actinium-labelled payloads across oncology indications. Regulatory agencies including the FDA and EMA have signalled increased familiarity with the theranostics modality following recent approvals, which may shorten the path to market for well-characterised agents. For ITM, the ASTRO data add to a growing body of evidence ahead of what will likely be a regulatory filing discussion once COMPETE and COMPOSE mature further.