Clinical outcomes of [ ¹⁷⁷ Lu]Lu-DOTA-TATE ( ¹⁷⁷ Lu-DOTATATE) vs everolimus (EVE) in managing patients (pts) with gastroenteropancreatic-neuroendocrine tumors (GEP-NETs): Real-world analysis of the PRIME initiative.

e16316 Background: GEP-NETs arise from neuroendocrine cells of the digestive tract (88%) or pancreas (12%). Therapies for progressive GEP-NETs include surgery, somatostatin analogs (SSA), chemotherapy, targeted therapy, and radioligand therapy. 177 Lu-DOTATATE is a radiolabeled SSA approved for progressive GEP-NETs based on NETTER-1 and shown to be an effective first-line therapy for Grade 2 and 3 GEP-NETs in NETTER-2. Prior to 177 Lu-DOTATATE approval, EVE, a mammalian target of rapamycin inhibitor, was the recommended therapy for progressive GEP-NETs. Here we describe pt characteristics and real-world outcomes of 177 Lu-DOTATATE vs EVE in pts with GEP-NETs. Methods: This was a retrospective, non-interventional, cohort study of pts treated with 177 Lu-DOTATATE or EVE using data from the open-source IQVIA Longitudinal Prescription and Pt Centric Medical Claims databases between Jul 1, 2017-Feb 28, 2025, representing the largest analysis of real-world GEP-NET data to date. Pt characteristics were assessed using descriptive statistics from 6 months prior to the index date (date of earliest evidence of 177 Lu-DOTATATE or EVE initiation). Following propensity-score matching of cohorts, overall survival (OS) and time to next systemic treatment (TTNT) were assessed with Kaplan-Meier and Cox models from index date to the end of follow-up. Results: The study included 5367 pts treated with 177 Lu-DOTATATE (n = 3410) or EVE (n = 1957). Prior to matching, pt characteristics were comparable between 177 Lu-DOTATATE and EVE groups, with a median (range) age of 67 (18-85) vs 65 (18-85) years. Prior exposure to systemic therapies was higher with 177 Lu-DOTATATE (68%) vs EVE (59%), with only 5% prior EVE exposure in the 177 Lu-DOTATATE group. The most common comorbidities in pts included hypertension (38% vs 37%); liver, gallbladder, and pancreatic diseases (29% vs 28%); and diabetes (24% vs 26%) for 177 Lu-DOTATATE vs EVE, respectively. Post-matching, the median (95% Cl) TTNT was not reached (NR) (70.2 months-NR) with 177 Lu-DOTATATE (n = 1559) vs 29.0 (25.2-34.6) months with EVE (n = 1559) (p < 0.0001). In pts who initiated a subsequent therapy (16% vs 38%) during the study, the median (range) TTNT was 20.5 (2.1-74.0) vs 8.0 (0.7-73.5) months with 177 Lu-DOTATATE vs EVE, respectively. Overall, 76% vs 73% of pts treated with 177 Lu-DOTATATE vs EVE were still alive at the end of follow-up. Cox proportional hazard and sensitivity analyses showed a robust, significant survival benefit for 177 Lu-DOTATATE vs EVE, with a hazard ratio (95% Cl) of 0.74 (0.59-0.92) for OS (p = 0.007). Conclusions: OS benefit and lower and less frequent treatment initiation after 177 Lu-DOTATATE vs EVE treatment, suggests a clinical benefit of 177 Lu-DOTATATE vs EVE with lower therapy burden in pts with GEP-NETs.