Lanreotide for advanced gastroenteropancreatic neuroendocrine tumors (GEP-NETs) in a Korean population: A multicenter prospective observational study (AIM-NETs).

4170 Background: Gastroenteropancreatic neuroendocrine tumors (GEP-NETs) are a heterogeneous group of malignancies. Somatostatin analogues (SSAs) are the standard of care for patients with unresectable or metastatic well-differentiated G1/G2 GEP-NETs. However, most pivotal data including the CLARINET trial were derived from Western cohorts. We prospectively evaluated the efficacy and safety of lanreotide in a real-world Korean cohort to bridge this geographic data gap. Methods: AIM-NETs is a prospective, observational, multicenter study of patients with unresectable or metastatic GEP-NETs treated with lanreotide. Patients received lanreotide 120 mg deep SC every 4 weeks (dose reduction to 90 mg permitted). Tumor response evaluation was done every 8 to 12 weeks according to the RECIST v1.1. The primary endpoint was the 2-year progression-free survival (PFS) rate. Secondary endpoints included median PFS and overall survival (OS), and safety. Results: Between Feb 2021 and Feb 2023, 71 patients were enrolled in five tertiary referral cancer centers in Korea. Median age was 59 years (range 25-82); 53.5% (n = 38) were male. Primary sites included pancreas (n = 40, 56.3%), rectum (8, 11.3%), colon (3, 4.2%) and stomach (3, 4.2%). Only two patients (2.8%) had functioning tumors. Tumor grades were G1 (n = 20, 28.2%), G2 (50, 70.4%) and G3 (1, 1.4%). The 2-year PFS rate was 50.6% (95% CI, 38.2%-63.0%) and median PFS was 26.0 months (95% CI, 15.2-32.7). The 2-year OS rate was 89.9% (82.9%-97.0%); median OS was not reached. The objective response rate was 23.5% (95% CI, 14.1%-35.4%). Higher tumor grade was significantly associated with worse PFS (p < 0.0001) and OS (p < 0.0001). High somatostatin receptor expression (Krenning score of 3 or higher on baseline Ga-68 DOTATOC scan) did not significantly correlate with PFS (p = 0.358) or OS (p = 0.199). No new safety signal of lanreotide were identified. Conclusions: Lanreotide provides robust disease control and a manageable safety profile in Asian patients with advanced GEP-NETs. The observed efficacy, including a favorable ORR, supports lanreotide as a standard of care in this population, aligning with previous clinical trial outcomes. Clinical trial information: NCT04696042 .