Efficacy and safety of 177 Lu‑DOTATATE in patients with advanced pancreatic neuroendocrine tumours: data from the NETTER-R international, retrospective study

Purpose NETTER-R aimed to determine the efficacy, safety and tolerability of 177 Lu-DOTATATE in patients with progressive, advanced pancreatic neuroendocrine tumours (panNETs) using retrospective real-world data from multiple sites. Methods This international study retrospectively included patients with panNETs treated with 177 Lu-DOTATATE. The primary endpoint was progression-free survival (PFS) by Response Evaluation Criteria in Solid Tumors version 1.1 (RECIST v1.1). Secondary endpoints included overall survival (OS), safety and tumour response. Results In total, 110 patients with panNETs were studied; 65.5% received a cumulative dose of 177 Lu-DOTATATE 29.6 GBq ± 10% (median: 7.4 GBq). In 62 patients with available RECIST v1.1 tumour response, the median PFS was 24.8 months (95% confidence interval [CI]: 17.5–34.5), and the objective response rate was 40.3% (95% CI: 28.1–53.6); all responses were partial. With a median follow up of 24.5 months (range: 2.0–123.4 months) after the first cycle of 177 Lu-DOTATATE, the median OS in the full analysis set ( n = 110) was 41.4 months (95% CI: 28.6–50.2). PFS (hazard ratio [HR]: 3.672; p = 0.0009) and OS (HR: 3.360; p < 0.0001) were longer in patients who received no chemotherapy prior to 177 Lu-DOTATATE than those who did. No treatment-emergent adverse events (TEAEs) led to treatment discontinuation. Grade 3 anaemia, lymphopenia and thrombocytopenia occurred in 0.9%, 5.4% and 0.9% of patients, respectively. No acute leukaemia or myelodysplastic syndrome was reported. Six patients (5.5%) had renal TEAEs. All renal grade ≥ 3 events were transient and did not lead to treatment modification. Conclusions These results reinforce the role of 177 Lu-DOTATATE for the treatment of patients with advanced, somatostatin receptor-positive panNETs.