In recent decades, the incidence of neuroendocrine tumors (NETs) has steadily increased. Due to the slow-growing nature of these tumors and the lack of early symptoms, most cases are diagnosed at advanced stages, when curative treatment options are no longer available. Prognosis and survival of patients with NETs are determined by the location of the primary lesion, biochemical functional status, differentiation, initial staging, and response to treatment. Somatostatin analogue (SSA) therapy has been a mainstay of antisecretory therapy in functioning neuroendocrine tumors, which cause various clinical symptoms depending on hormonal hypersecretion. Beyond symptomatic management, recent research demonstrates that SSAs exert antiproliferative effects and inhibit tumor growth via the somatostatin receptor 2 (SSTR2). Both the PROMID (placebo-controlled, prospective, randomized study in patients with metastatic neuroendocrine midgut tumors) and the CLARINET (controlled study of lanreotide antiproliferative response in neuroendocrine tumors) trial showed a statistically significant prolongation of time to progression/progression-free survival (TTP/PFS) upon SSA treatment, compared to placebo. Moreover, the combination of SSA with peptide receptor radionuclide therapy (PRRT) in small intestinal NETs has proven efficacy in the phase 3 neuroendocrine tumours therapy (NETTER 1) trial. PRRT is currently being tested for enteropancreatic NETs versus everolimus in the COMPETE trial, and the potential of SSTR-antagonists in PRRT is now being evaluated in early phase I/II clinical trials. This review provides a synopsis on the pharmacological development of SSAs and their use as antisecretory drugs. Moreover, this review highlights the clinical evidence of SSAs in monotherapy, and in combination with other treatment modalities, as applied to the antiproliferative management of neuroendocrine tumors with special attention to recent high-quality phase III trials.

Background and Aims: Nucleotide‐binding oligomerization domain‐like receptor‐family pyrin domain‐containing 3 (NLRP3) inflammasome activation has been shown to result in liver fibrosis. Mechanisms and downstream signaling remain incompletely understood. Here, we studied the role of IL‐18 in hepatic stellate cells (HSCs), and its impact on liver fibrosis. Approach and Results: We observed significantly increased serum levels of IL‐18 (128.4 pg/ml vs. 74.9 pg/ml) and IL‐18 binding protein (BP; 46.50 ng/ml vs. 15.35 ng/ml) in patients with liver cirrhosis compared with healthy controls. Single cell RNA sequencing data showed that an immunoregulatory subset of murine HSCs highly expresses Il18 and Il18r1. Treatment of cultured primary murine HSC with recombinant mouse IL‐18 accelerated their transdifferentiation into myofibroblasts. In vivo, IL‐18 receptor‐deficient mice had reduced liver fibrosis in a model of fibrosis induced by HSC‐specific NLRP3 overactivation. Whole liver RNA sequencing analysis from a murine model of severe NASH‐induced fibrosis by feeding a choline‐deficient, L‐amino acid‐defined, high fat diet showed that genes related to IL‐18 and its downstream signaling were significantly upregulated, and Il18 ^−/− mice receiving this diet for 10 weeks showed protection from fibrotic changes with decreased number of alpha smooth muscle actin‐positive cells and collagen deposition. HSC activation triggered by NLRP3 inflammasome activation was abrogated when IL‐18 signaling was blocked by its naturally occurring antagonist IL‐18BP. Accordingly, we observed that the severe inflammatory phenotype associated with myeloid cell‐specific NLRP3 gain‐of‐function was rescued by IL‐18BP. Conclusions: Our study highlights the role of IL‐18 in the development of liver fibrosis by its direct effect on HSC activation identifying IL‐18 as a target to treat liver fibrosis.

Hepatic inflammasome activation is considered a major contributor to liver fibrosis in NASH. Apoptosis signal–regulating kinase 1 (ASK1) is an apical mitogen-activated protein kinase that activates hepatic JNK and p38 to promote apoptosis, inflammation, and fibrosis. The aim of the current study was to investigate whether pharmacologic inhibition of ASK1 could attenuate hepatic fibrosis driven by inflammasome activation using gain-of-function NOD-like receptor protein 3 ( Nlrp3 ) mutant mice. Tamoxifen-inducible Nlrp3 knock-in ( Nlrp3 ^A350V/+ CreT-KI) mice and WT mice were administered either control chow diet or diet containing the selective ASK1 inhibitor GS-444217 for 6 weeks. Livers of Nlrp3 -KI mice had increased inflammation, cell death, and fibrosis and increased phosphorylation of ASK1, p38, and c-Jun. GS-444217 reduced ASK1 pathway activation, liver cell death, and liver fibrosis. ASK1 inhibition resulted in a significant downregulation of genes involved in collagen production and extracellular matrix deposition, as well as in a reduced hepatic TNF-α expression. ASK1 inhibition also directly reduced LPS-induced gene expression of Collagen 1A1 ( Col1a1 ) in hepatic stellate cells isolated from Nlrp3 -KI mice. In conclusion, ASK1 inhibition reduced liver cell death and fibrosis downstream of inflammatory signaling induced by NLRP3. These data provide mechanistic insight into the antifibrotic mechanisms of ASK1 inhibition.

Bile acids (BA) as important signaling molecules are considered crucial in development of cholestatic liver injury, but there is limited understanding on the involved cell types and signaling pathways. The aim of this study was to evaluate the inflammatory and fibrotic potential of key BA and the role of distinct liver cell subsets focusing on the NLRP3 inflammasome. C57BL/6 wild-type (WT) and Nlrp3^−/− mice were fed with a diet supplemented with cholic (CA), deoxycholic (DCA) or lithocholic acid (LCA) for 7 days. Additionally, primary hepatocytes, Kupffer cells (KC) and hepatic stellate cells (HSC) from WT and Nlrp3^−/− mice were stimulated with aforementioned BA ex vivo. LCA feeding led to strong liver damage and activation of NLRP3 inflammasome. Ex vivo KC were the most affected cells by LCA, resulting in a pro-inflammatory phenotype. Liver damage and primary KC activation was both ameliorated in Nlrp3-deficient mice or cells. DCA feeding induced fibrotic alterations. Primary HSC upregulated the NLRP3 inflammasome and early fibrotic markers when stimulated with DCA, but not LCA. Pro-fibrogenic signals in liver and primary HSC were attenuated in Nlrp3^−/− mice or cells. The data shows that distinct BA induce NLRP3 inflammasome activation in HSC or KC, promoting fibrosis or inflammation.

Summary: Background and Aims: Phase III trials have established atezolizumab plus bevacizumab as the novel standard of care for patients with unresectable hepatocellular carcinoma (HCC). However, these trials raised concerns regarding treatment efficacy in non‐viral HCC, and it remains unclear whether combination immunotherapy is safe and effective in patients with advanced cirrhosis.Methods: One hundred patients with unresectable HCC initiated therapy with atezolizumab plus bevacizumab at our centre between January 2020 and March 2022. The control cohort consisted of 80 patients with advanced HCC who received either sorafenib (n = 43) or lenvatinib (n = 37) as systemic treatment.Results: Overall survival (OS) and progression‐free survival (PFS) were significantly longer within the atezolizumab/bevacizumab group and comparable to phase III data. The benefits in terms of increased objective response rate (ORR), OS and PFS were consistent across subgroups, including non‐viral HCC (58%). The ROC‐optimised neutrophil‐to‐lymphocyte ratio (NLR) cut‐off of 3.20 was the strongest independent predictor of ORR and PFS. In patients with advanced cirrhosis Child–Pugh B, liver function was significantly better preserved with immunotherapy. Patients with Child–Pugh B cirrhosis showed similar ORR but shorter OS and PFS compared to patients with preserved liver function.Conclusions: Atezolizumab plus bevacizumab showed good efficacy and safety in patients with unresectable HCC and partially advanced liver cirrhosis in a real‐world setting. Moreover, the NLR was able to predict response to atezolizumab/bevacizumab treatment and may guide patient selection.