Dr Strosberg on Survival Outcomes With 177Lu-edotreotide in Select SSTR+ GEP-NET Subgroups

"[The PFS] improvement was only statistically significant in the second-line vs first-line setting. The main reason for that is because [approximately] 85% of patients were [treated in the] second line, so there was enough power to be able to detect a difference between treatment arms."

Jonathan Strosberg, MD, a professor at Moffitt Cancer Center and leader of Moffitt’s Neuroendocrine Tumor Division and Department of Gastrointestinal Oncology Research Program shared data from a subgroup analysis of the phase 3 COMPETE trial (NCT03049189), which evaluated ¹⁷⁷Lu-edotreotide (ITM-11) in patients with grade 1 or 2, somatostatin receptor (SSTR)–positive gastroenteropancreatic neuroendocrine tumors (GEP-NETs).

The study’s primary stratification factors included primary tumor origin (gastrointestinal vs pancreatic) and prior therapy history, Strosberg detailed. Findings presented at the 2025 NANETS Annual Symposium showed improvements in both progression-free survival (PFS) and overall response rate (ORR) with 177Lu-edotreotide compared with everolimus (Afinitor) across various subgroups. Of note, this benefit in PFS was statistically significant in patients treated in the second-line setting (HR, 0.678; 95% CI, 0.47-0.98; P = .039). In this subgroup, the median PFS was 23.9 months for the 177Lu-edotreotide arm (n = 177) vs 14.1 months for the everolimus arm (n = 85).

Although not statistically significant, numerical trends consistently favored ¹⁷⁷Lu-edotreotide in other cohorts. This included patients with grade 1 tumors (HR, 0.657; P = .071), grade 2 tumors (HR, 0.635; P = .102), gastroenteric NETs (GE-NETs; HR, 0.636; P = .090), and pancreatic NETs (P-NETs; HR, 0.699; P = .114).

Strosberg concluded that the statistical significance observed in the second-line group was primarily due to the way the study was powered, as approximately 85% of the total participants were treated in the second line. He emphasized that despite the lack of statistical significance in other subgroups, including those in the first-line setting, the strong trends toward improvement across tumor grades and locations suggest a broad benefit for this therapy in the GEP-NET population.