Towards a Radio-guided Surgery with β−\beta^{-} Decays: Uptake of a somatostatin analogue (DOTATOC) in Meningioma and High Grade Glioma

A novel radio guided surgery (RGS) technique for cerebral tumors using $\beta^{-}$ radiation is being developed. Checking the availability of a radio-tracer that can deliver a $\beta^{-}$ emitter to the tumor is a fundamental step in the deployment of such technique. This paper reports a study of the uptake of 90Y labeled (DOTATOC) in the meningioma and the high grade glioma (HGG) and a feasibility study of the RGS technique in these cases.Comment: 21 pages, 5 figure

Phase 3 Trial of 177Lu-Dotatate for Midgut Neuroendocrine Tumors

Background Patients with advanced midgut neuroendocrine tumors who have had disease progression during first-line somatostatin analogue therapy have limited therapeutic options. This randomized, controlled trial evaluated the efficacy and safety of lutetium-177 (177Lu)-Dotatate in patients with advanced, progressive, somatostatin-receptor-positive midgut neuroendocrine tumors. Methods We randomly assigned 229 patients who had well-differentiated, metastatic midgut neuroendocrine tumors to receive either 177Lu-Dotatate (116 patients) at a dose of 7.4 GBq every 8 weeks (four intravenous infusions, plus best supportive care including octreotide long-acting repeatable [LAR] administered intramuscularly at a dose of 30 mg) (177Lu-Dotatate group) or octreotide LAR alone (113 patients) administered intramuscularly at a dose of 60 mg every 4 weeks (control group). The primary end point was progression-free survival. Secondary end points included the objective response rate, overall survival, safety, and the side-effect profile. The final analysis of overall survival will be conducted in the future as specified in the protocol; a prespecified interim analysis of overall survival was conducted and is reported here. Results At the data-cutoff date for the primary analysis, the estimated rate of progression-free survival at month 20 was 65.2% (95% confidence interval [CI], 50.0 to 76.8) in the 177Lu-Dotatate group and 10.8% (95% CI, 3.5 to 23.0) in the control group. The response rate was 18% in the 177Lu-Dotatate group versus 3% in the control group (P<0.001). In the planned interim analysis of overall survival, 14 deaths occurred in the 177Lu-Dotatate group and 26 in the control group (P=0.004). Grade 3 or 4 neutropenia, thrombocytopenia, and lymphopenia occurred in 1%, 2%, and 9%, respectively, of patients in the 177Lu-Dotatate group as compared with no patients in the control group, with no evidence of renal toxic effects during the observed time frame. Conclusions Treatment with 177Lu-Dotatate resulted in markedly longer progression-free survival and a significantly higher response rate than high-dose octreotide LAR among patients with advanced midgut neuroendocrine tumors. Preliminary evidence of an overall survival benefit was seen in an interim analysis; confirmation will be required in the planned final analysis. Clinically significant myelosuppression occurred in less than 10% of patients in the 177Lu-Dotatate group. (Funded by Advanced Accelerator Applications; NETTER-1 ClinicalTrials.gov number, NCT01578239 ; EudraCT number 2011-005049-11

Neuroendokrin daganat májmetasztázisainak teljes és tartós remissziója szomatosztatinanalóg-kezelés hatására

Somatostatin analogues represent a major treatment modality in the therapy of neuroendocrine tumors. Their efficacy is well documented in the inhibition of hormone secretion; however, novel data seem to underline their effectiveness in tumor regression, as well. In this report authors present a case of type 1 neuroendocrine tumors of the stomach associated with liver metastases. Somatostatin analogue treatment resulted in a complete regression of the primary tumor and the metastases within two years. This case draws attention on the importance of somatostatin analogue treatment not only in the control of hormonal symptoms but also in the inhibition of tumor growth. Orv. Hetil., 2011, 152, 407-410

Octreotide, a Somatostatin Analogue, Fails to Inhibit Hypoxia-induced Retinal Neovascularization in the Neonatal Rat

Objective: Octreotide, a somatostatin analogue, has been shown to prevent angiogenesis in diverse in vitro models. We evaluated its effect on retinal neovascularization in vivo, using a neonatal rat retinopathy model

E-cadherin expression is associated with somatostatin analogue response in acromegaly

Acromegaly is a rare disease resulting from hypersecretion of growth hormone (GH) and insulin‐like growth factor 1 (IGF1) typically caused by pituitary adenomas, which is associated with increased mortality and morbidity. Somatostatin analogues (SSAs) represent the primary medical therapy for acromegaly and are currently used as first‐line treatment or as second‐line therapy after unsuccessful pituitary surgery. However, a considerable proportion of patients do not adequately respond to SSAs treatment, and therefore, there is an urgent need to identify biomarkers predictors of response to SSAs. The aim of this study was to examine E‐cadherin expression by immunohistochemistry in fifty‐five GH‐producing pituitary tumours and determine the potential association with response to SSAs as well as other clinical and histopathological features. Acromegaly patients with tumours expressing low E‐cadherin levels exhibit a worse response to SSAs. E‐cadherin levels are associated with GH‐producing tumour histological subtypes. Our results indicate that the immunohistochemical detection of E‐cadherin might be useful in categorizing acromegaly patients based on the response to SSAs.ISCIII‐Subdirección General de Evaluación y Fomento de la Investigación PI13/02043 PI16/00175FEDER PI13/02043 PI16/00175Junta de Andalucía A‐0023‐2015 A‐0003‐2016 CTS‐1406 BIO‐0139Andalusian Ministry of Health C‐0015‐2014CIBERobn PI13/ 02043 PI16/0017

Somatostatin Analogues in the Treatment of Neuroendocrine Tumors: Past, Present and Future

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

In vitro and in vivo evaluation of a somatostatin analogue released from PLGA microspheres

The purpose of this study was to design poly(lactide-co-glycolide) (PLGA) microspheres for the continuous delivery of the somatostatin analogue, vapreotide, over 2–4 weeks. The microspheres were produced by spray-drying and the desired characteristics, i.e. high encapsulation efficiency and controlled release over 2–4 weeks, achieved through optimizing the type of polymer, processing solvent, and co-encapsulated additive. The in vitro release was tested in fetal bovine serum preserved with 0.02% of thiomersal. Furthermore, formulations were injected intramuscularly into rats to obtain pharmacokinetic profiles. Encapsulation efficiency was between 34 and 91%, depending on the particular formulation. The initial peptide release (within 6 h) was lowest, i.e. 1 ng/ml) over 21–28 days in rats was the one made with end-group uncapped PLGA 50:50, the solvent acetic acid and the additive polyethyleneglycol. In conclusion, the optimization of formulation parameters allowed us to produce vapreotide-loaded PLGA microspheres of suitable characteristics for therapeutic use

Neoadjuvant chemotherapy with capecitabine and temozolomide for unresectable pancreatic neuroendocrine tumor.

Pancreatic neuroendocrine tumors (PNETs) are relatively rare tumors that arise in the endocrine cells of the pancreas. Historically, somatostatin analogues have been used in this disease primarily for symptom control and, to a limited extent, disease stability. More recently, sunitinib and everolimus have been approved for advanced stage PNETs based on a survival benefit. However, both agents have a &lt;10% actual response rate and cause nontrivial side effect profiles that limit duration of therapy. In locally advanced disease, there is a paucity of data to support an optimal neoadjuvant approach with the expectation of down-staging to allow for curative resection. We describe in this case a young woman who was successfully down-staged using a chemotherapy regimen of capecitabine and temozolomide with minimal toxicity

Análise de custo-efetividade de análogos da somatostatina no tratamento de acromegalia no Brasil

This study aims to compare economic and patient impacts of the treatment of acromegaly with two different somatostatin analogues (octreotide LAR and lanreotide SR) in Brazil. A cost-effectiveness analysis was carried out under the Brazilian Public Health Care System (SUS) perspective. A decision analytical model was developed based on the Brazilian Public Health Care System Clinical Guideline for Acromegaly. A hypothetical cohort of 276 patients was followed for two years. Data were extracted from literature and administrative databases. Based on the analytical model, treatment with octreotide LAR would avoid 12 and 17 cases of GH and IGF-I elevated serum levels, respectively. Octreotide LAR was a cost-saving strategy, with net savings of R$10,448,324 (US$4,465,096) to SUS. Annual net savings per patient were R$18,928 (US$8,089). Treatment of acromegaly with octreotide LAR is a dominant strategy when compared to the treatment with lanreotide SR in Brazil. Sensitivity analysis did not alter the cost-saving status.O objetivo deste estudo é comparar o impacto econômico e o impacto nos pacientes com acromegalia do tratamento com dois diferentes análogos de somatostatina (octreotida LAR e lanreotide SR) no Brasil. Um estudo de custoefetividade foi realizado a partir da perspectiva do Sistema Único de Saúde (SUS). Foi desenvolvido um modelo analítico de decisão baseado no Protocolo Clínico e Diretrizes Terapêuticas de Acromegalia do SUS. Uma coorte hipotética de 276 pacientes foi seguida por dois anos. Dados foram obtidos da literatura e bases de dados oficiais do SUS. Baseado no modelo analítico, o tratamento com octreotida LAR evitaria 12 e 17 casos com níveis elevados de GH e IGF-I, respectivamente. Octreotida LAR foi uma estratégia econômica, gerando economia de R$10.448.324 (US$4.465.096) para o SUS. A economia anual por paciente foi de R$18.928 (US$8.089). O tratamento de acromegalia com octreotida LAR é estratégia dominante quando comparado com o tratamento com lanreotida SR no Brasil. A análise de sensibilidade não alterou seu status de econômica