XTR008 Achieves Dramatic Progression-Free Survival Benefit in Advanced Gastroenteropancreatic Neuroendocrine Tumors
核心洞察
XTR008, a novel 177Lu-dotatate-based peptide receptor radionuclide therapy, demonstrated a median progression-free survival of 24.77 months compared to 5.78 months with octreotide LAR in patients with advanced GEP-NETs.
The phase 3 trial showed a remarkable 94% reduction in disease progression risk (HR 0.06) and achieved a 55.6% overall response rate versus 2.1% with standard therapy.
Despite higher rates of hematologic toxicities, XTR008 maintained a manageable safety profile while significantly improving quality of life across multiple dimensions.
XTR008, a no-carrier-added 177Lu-dotatate-based peptide receptor radionuclide therapy (PRRT), has demonstrated unprecedented efficacy in treating patients with well-differentiated, somatostatin receptor (SSTR)-positive gastroenteropancreatic neuroendocrine tumors (GEP-NETs), according to phase 3 trial results presented at the 2025 European Society for Medical Oncology (ESMO) Congress.
The XT-XTR008-3-01 study (NCT05459844) showed that XTR008 significantly extended median progression-free survival to 24.77 months (95% CI, 22.11–not evaluable) compared to 5.78 months (95% CI, 5.65–8.41) with high-dose octreotide long-acting repeatable (LAR), representing a 94% reduction in the risk of disease progression (HR, 0.06; 95% CI, 0.031–0.135; P <.0001).
Remarkable Response Rates and Duration
The therapeutic superiority of XTR008 extended beyond progression-free survival metrics. As of the June 2025 data cutoff, the overall response rate in the XTR008 arm reached 55.6% with a median duration of response of 19.8 months (95% CI, 11.04–not evaluable). In stark contrast, the octreotide LAR arm achieved only a 2.1% overall response rate with a median duration of response of 8.4 months.
Additionally, 39.3% of patients in the XTR008 group achieved stable disease, while 70.1% of patients in the octreotide LAR group achieved stable disease. The treatment also demonstrated improvements in quality of life compared with octreotide LAR across multiple dimensions, including functional and symptom scales.
Safety Profile and Tolerability
While XTR008 showed superior efficacy, it was associated with a higher incidence of treatment-related adverse events. A total of 95.9% (n = 94) of patients in the XTR008 arm experienced treatment-related adverse events compared to 58.3% (n = 56) in the octreotide LAR arm. Grade ≥3 treatment-related adverse events occurred in 51.0% (n = 50) and 11.5% (n = 11) of patients, respectively.
The most common treatment-related adverse events were hematologic toxicities, including decreased lymphocytes (72.4%), anemia (54.1%), neutropenia (49.0%), and decreased platelets (49.0%). Despite these toxicities, the safety profile was deemed manageable by investigators.
Study Design and Patient Population
The randomized, controlled phase 3 trial enrolled patients across sites in China, randomizing them 1:1 to receive either XTR008 (n = 99) at 200 mCi every 8 weeks for 4 cycles or octreotide LAR (n = 97) 60 mg every 4 weeks. The primary endpoint was progression-free survival, with secondary endpoints including duration of response, overall survival, quality of life, and disease control rate.
Eligible patients were required to have confirmed low/intermediate-grade (G1/G2) advanced GEP-NET, disease progression after at least 12 weeks of fixed dose octreotide LAR, and an ECOG performance status of 0 to 1. Stratification factors included primary tumor site (pancreatic vs nonpancreatic), pathological tumor grade (1 vs 2), and duration of most recent treatment (≤6 months vs >6 months).
Clinical Context and Unmet Need
The study addresses a significant clinical challenge in GEP-NET management. As noted by the investigators, GEP-NETs exhibit considerable heterogeneity, making it challenging to develop effective treatments. In later-line settings, the tumors become more aggressive and resistant to therapy.
The research is particularly relevant for Asian populations, as the distribution of GEP-NETs in China originates more from primary pancreatic, gastric, and rectal sites, compared to Western populations where midgut origins are most common. While the phase 3 NETTER-1 trial established PRRT as a standard treatment for midgut NETs, evidence remained limited for its efficacy in NETs from other primary sites.
Overall Survival Trends
Although overall survival data were not mature at the time of analysis, a positive trend was observed in the XTR008 arm with a separation of Kaplan-Meier curves beginning around 9 months after randomization, suggesting potential long-term survival benefits that may emerge with longer follow-up.
The results were presented by Rongrui Liu, MD, associate chief physician at Chinese PLA Hospital in Beijing, China, who declared no conflicts of interest related to the study.