Evaluating lanreotide as maintenance therapy after first-line treatment in patients with non-resectable duodeno-pancreatic neuroendocrine tumours

Circulating hsa-miR-5096 predicts 18F-FDG PET/CT positivity and modulates somatostatin receptor 2 expression: a novel miR-based assay for pancreatic neuroendocrine tumors

Gastro-entero-pancreatic neuroendocrine tumors (GEP-NETs) are rare diseases encompassing pancreatic (PanNETs) and ileal NETs (SINETs), characterized by heterogeneous somatostatin receptors (SSTRs) expression. Treatments for inoperable GEP-NETs are limited, and SSTR-targeted Peptide Receptor Radionuclide Therapy (PRRT) achieves variable responses. Prognostic biomarkers for the management of GEP-NET patients are required. ¹⁸F-FDG uptake is a prognostic indicator of aggressiveness in GEP-NETs. This study aims to identify circulating and measurable prognostic miRNAs associated with ¹⁸F-FDG-PET/CT status, higher risk and lower response to PRRT.

Methods

Whole miRNOme NGS profiling was conducted on plasma samples obtained from well-differentiated advanced, metastatic, inoperable G1, G2 and G3 GEP-NET patients enrolled in the non-randomized LUX (NCT02736500) and LUNET (NCT02489604) clinical trials prior to PRRT (screening set, n= 24). Differential expression analysis was performed between ¹⁸F-FDG positive (n=12) and negative (n=12) patients. Validation was conducted by Real Time quantitative PCR in two distinct well-differentiated GEP-NET validation cohorts, considering the primary site of origin (PanNETs n=38 and SINETs n=30). The Cox regression was applied to assess independent clinical parameters and imaging for progression-free survival (PFS) in PanNETs. In situ RNA hybridization combined with immunohistochemistry was performed to simultaneously detect miR and protein expression in the same tissue specimens. This novel semi-automated miR-protein protocol was applied in PanNET FFPE specimens (n=9). In vitro functional experiments were performed in PanNET models.

Results

While no miRNAs emerged to be deregulated in SINETs, hsa-miR-5096, hsa-let-7i-3p and hsa-miR-4311 were found to correlate with ¹⁸F-FDG-PET/CT in PanNETs (p-value:<0.005). Statistical analysis has shown that, hsa-miR-5096 can predict 6-month PFS (p-value:<0.001) and 12-month Overall Survival upon PRRT treatment (p-value:<0.05), as well as identify ¹⁸F-FDG-PET/CT positive PanNETs with worse prognosis after PRRT (p-value:<0.005). In addition, hsa-miR-5096 inversely correlated with both SSTR2 expression in PanNET tissue and with the ⁶⁸Gallium-DOTATOC captation values (p-value:<0.05), and accordingly it was able to decrease SSTR2 when ectopically expressed in PanNET cells (p-value:<0.01).

Conclusions

hsa-miR-5096 well performs as a biomarker for ¹⁸F-FDG-PET/CT and as independent predictor of PFS. Moreover, exosome-mediated delivery of hsa-miR-5096 may promote SSTR2 heterogeneity and thus resistance to PRRT.

Lanreotide as maintenance therapy after first-line treatment in patients with non-resectable duodeno-pancreatic neuroendocrine tumours: An international double-blind, placebo-controlled randomised phase II trial - Prodige 31 REMINET: An FFCD study

BACKGROUND

Following European guidelines, patients with aggressive metastatic or locally advanced, non-resectable, duodeno-pancreatic (DP) neuroendocrine tumours (NETs) should receive systemic combination chemotherapy until progression. Aggressive disease is defined as progressive and/or symptomatic metastases with or without significant hepatic invasion (>30-50%), and/or bone metastases.

METHODS

This academic randomised, double-blind, placebo-controlled phase II study aims to evaluate lanreotide autogel 120 mg (LAN) as maintenance treatment after at least 2 months of first-line treatment (L1) in aggressive G1-G2 DP-NET. Patients were randomly assigned in a 1:1 ratio to receive LAN or placebo (PBO), every 28 days, until progression or toxicity. The primary end-point was progression-free survival (PFS) at 6 months.

RESULTS

Among the 118 planned patients, 53 were included. Of these, 81.1% had a G2 tumour, and 90.6% had metastatic disease. L1 therapy consisted of chemotherapy (96.8%). Median duration of L1 was 4.6 months (range: 2.0-7.7). At the time of randomisation, 81.1% of patients had stable disease. Median follow-up was 27.0 months (95% CI: 19.5; 31.2). PFS at 6 months was 73.1% (90% CI: 55.3; 86.6) in LAN versus 54.2% (90% CI: 35.8; 71.8) in PBO. Median PFS was 19.4 months (95% CI: 7.6; 32.6) and 7.6 months (95% CI: 3.0; 9.0), respectively. Median overall survival was 41.9 months in PBO and was not reached in LAN. The toxicity profile was mainly grade 1-2 expected toxicities.

CONCLUSIONS

The encouraging results of lanreotide autogel 120 mg as a maintenance treatment after L1 in aggressive G1/2 DP-NET should be confirmed.

TRIAL REGISTRATION

NCT02288377 (clinicaltrials.gov).

The Evolving Role of Radioembolization in the Treatment of Neuroendocrine Liver Metastases

Simple Summary

This review provides basic insights into radioembolization, also known as selective internal radiation therapy, in patients suffering from neuroendocrine liver metastases. Radioembolization is a treatment that uses radioactive beads that are implanted intra-arterially to locally irradiate liver tumors. The available literature on radioembolization in neuroendocrine liver metastases show promising results in terms of efficacy and toxicity and will be discussed in more detail. However, data in the field of NELM need clarification, and this review also discusses the caveats, challenges and new insights when considering radioembolization in neuroendocrine liver metastases.

Abstract

At diagnosis, 21–50% of neuroendocrine tumors already have distant metastases, of which the liver is most commonly affected. Unfortunately, the presence of neuroendocrine liver metastases (NELM) is the most incriminating factor for survival. At NELM diagnosis, 60–70% of patients suffer from bilobar multifocal disease, making them ineligible for surgical resection. With limited systemic options, a clinical need for liver-directed treatments exists. Trans-arterial (bland) embolization, chemoembolization and radioembolization have been increasingly used in the treatment of NELM. In recent years, radioembolization (also known as selective internal radiation therapy) has gained attention due to promising tumor reductive results, limited toxicities and increasing scientific evidence. This review provides basic insights into radioembolization as a technique, a summary of available literature on radioembolization in NELM, and discusses caveats, challenges and new insights when considering radioembolization in NELM.