New analyses from the SwissNET registry and the Phase 3 COMPETE study provide additional clinical insights into re-treatment outcomes and radiation dosimetry of investigational ¹⁷⁷Lu-edotreotide in patients with gastroenteropancreatic neuroendocrine tumors.
ITM Isotope Technologies Munich SE (ITM) and Lumara Bio announced new real-world re-treatment data and dosimetry results for ¹⁷⁷Lu-edotreotide (ITM-11) in patients with gastroenteropancreatic neuroendocrine tumors (GEP-NETs) presented at the American Society for Radiation Oncology (ASTRO) 2026 Annual Meeting.
The findings were presented in two posters, including an analysis from the SwissNET registry evaluating real-world outcomes after re-treatment with ¹⁷⁷Lu-edotreotide and a dosimetry analysis from Substudy A of the Phase 3 COMPETE trial.
SwissNET registry analysis evaluates ¹⁷⁷Lu-edotreotide re-treatment outcomes
The retrospective SwissNET registry analysis included 49 adults with metastatic, well-differentiated, somatostatin receptor (SSTR)-positive neuroendocrine tumors who experienced disease progression at least 12 months after completing an initial course of ¹⁷⁷Lu-edotreotide.
Among these patients:
- 37 patients received re-treatment with ¹⁷⁷Lu-edotreotide.
- 12 patients received non-radiopharmaceutical systemic anti-cancer therapies.
The analysis evaluated real-world progression-free survival (rwPFS) and overall survival (OS).
Patients receiving ¹⁷⁷Lu-edotreotide re-treatment had:
- Median rwPFS of 12.5 months compared with 4.8 months in patients receiving non-radiopharmaceutical systemic therapies.
- Median OS of 90.1 months compared with 39.8 months in the non-radiopharmaceutical systemic therapy group.
According to the companies, these findings represent additional real-world data evaluating re-treatment with ¹⁷⁷Lu-edotreotide in patients with GEP-NETs.
Dosimetry results from Phase 3 COMPETE trial
A second presentation included dosimetry findings from Substudy A of the Phase 3 COMPETE trial (NCT03049189), evaluating absorbed radiation doses following treatment with ¹⁷⁷Lu-edotreotide.
The analysis included:
- Healthy organ dosimetry data from 17 patients.
- Tumor dosimetry data from 17 lesions in 9 patients.
The results showed that:
- Tumor absorbed radiation doses were higher compared with absorbed doses in normal organs.
- Kidney absorbed dose coefficients showed low intra-patient variability, with a median variability of 14%.
- Tumor-to-kidney absorbed dose coefficient ratios remained greater than 1 across treatment cycles.
The companies stated that these findings provide additional information on radiation dose distribution following treatment with ¹⁷⁷Lu-edotreotide.
Dr. Celine Wilke, Chief Medical Officer of ITM, said:
“These real-world insights as well as the dosimetry data provide signals that radiopharmaceutical therapy represents an approach worth investigating in settings in which it has not yet been studied.”
COMPETE Phase 3 trial of ¹⁷⁷Lu-edotreotide
The Phase 3 COMPETE trial (NCT03049189) is evaluating ¹⁷⁷Lu-edotreotide compared with everolimus in patients with inoperable, progressive Grade 1 or Grade 2 GEP-NETs.
According to ITM and Lumara Bio, the trial met its primary endpoint, demonstrating a statistically significant improvement in progression-free survival compared with everolimus.
The companies are also evaluating ¹⁷⁷Lu-edotreotide in the ongoing Phase 3 COMPOSE study in patients with well-differentiated, aggressive Grade 2 or Grade 3 SSTR-positive GEP-NETs.
Read further on OncoDaily: COMPETE Trial: [177Lu]Lu-Edotreotide Prolongs PFS vs Everolimus in Advanced GEP NETs
