Treatment response and clinical outcomes of well-differentiated high-grade neuroendocrine tumors to 177Lu-DOTATATE.

2021 ◽  
Vol 39 (3_suppl) ◽  
pp. 368-368
Author(s):  
Kelley Lauren Coffman ◽  
Lisa Bodei ◽  
Tiffany Le ◽  
Ye Choi ◽  
Joanne F. Chou ◽  
...  

368 Background: 177Lu-DOTATATE is an approved therapy for somatostatin receptor (sstr) positive gastroenteropancreatic neuroendocrine tumors (NETs). There are little data available on response and outcomes for well differentiated (WD) high grade (HG) NETs treated with 177Lu-DOTATATE. Methods: Pts with WD HGNETs treated with 177Lu-DOTATATE at MSK from 2018-2020 were identified. Demographics, response to treatment, and progression-free survival (PFS) were determined. In pts with archival tumor tissue, next-generation sequencing (NGS) was performed through an institutional platform (MSK-IMPACT). Results: 19 pts were identified (mean age 54, 63% female). Site of tumor origin included: pancreas (14/19, 74%), small bowel (2/19, 10.5%), rectal (2/19, 10.5%), lung (1/19, 5%). Average tumor Ki-67 was 34.8 (range 22-56). All tumors were sstr avid on pre-treatment Ga68-DOTATATE PET/CT; none of the patients had sstr negative lesions detected. Median number of prior treatments (systemic and/or liver-directed) was 4 (range 2-7). All pts had progressive disease prior to initiation of 177Lu-DOTATATE. 13 pts (68%) completed all four treatment cycles; treatment was incomplete in 6 pts due to treatment-related toxicities (n = 3) and clinical progression (n = 3). Best response by radiographic report was available in 16 patients (84%):10/16 (63%) with partial response, 1/16 (6%) with stable disease, 5/16 (31%) with disease progression. One pt with stable disease as best response received two additional cycles of 177Lu-DOTATATE at progression. Median PFS (from date of first treatment with 177Lu-DOTATATE until progression/death) was 11.1 months (95% CI 10.6 to NA). Five pts (26%) experienced dose modifying toxicity with 177Lu-DOTATATE. The most common treatment-related toxicities were thrombocytopenia (9 pts, 47%; G3/4 in 1 pt, 5%), anemia (7 pts, 37%; G3/4 in 2 pts, 10.5%), leukopenia (6 pts, 32%; G3/4 in 0 pts), and AST/ALT elevation (4 pts, 21%; G3/4 in 0 pts). NGS results were available in the tumor tissue of 13 pts (68%). The most commonly observed alterations were in MEN1 (6/13, 46%) and DAXX (4/13, 31%). No RB1 alterations were identified. Conclusions: We observed a meaningful disease control rate of 69% during treatment of WD HGNETs with 177Lu-DOTATATE. In this heavily pre-treated population, more than half of pts received all four treatment cycles with treatment-related toxicities largely bone-marrow related, as expected, based on historical data. As would be expected in sstr avid tumors, the vast majority had alterations in chromatin remodeling genes (MEN1, DAXX) consistent with WD NETs, with no RB1 alterations identified.

2020 ◽  
Vol 38 (4_suppl) ◽  
pp. 617-617
Author(s):  
Patrick Walsh McGarrah ◽  
Timothy J. Hobday ◽  
Jason Scott Starr ◽  
Ayse T. Kendi ◽  
Rondell P. Graham ◽  
...  

617 Background: Currently, there is no published data on the efficacy of SSAs for well-differentiated G3 NETs. Randomized trials have demonstrated a progression-free survival (PFS) benefit and limited tumor response for lower grade 1-2 NETs, but the optimal systemic therapy for metastatic/unresectable G3 NETs is unknown. We sought to evaluate the efficacy of SSAs in G3 NETs. Methods: We performed a retrospective analysis of Mayo Clinic patients treated with SSAs for metastatic/unresectable G3 NETs, querying data from 1992 - present. Inclusion criteria were: centrally reviewed pathology confirming well-differentiated morphology, G3 based on WHO classification, SSA monotherapy, and radiological data available to assess response. Patients who had prior lines of treatment were included as long they subsequently were treated with single-agent SSA. Poorly-differentiated tumors were excluded. The primary endpoint was PFS. Best overall response was determined by radiographic regression, stabilization, or progression of tumor size. Results: Ninety patient records were reviewed, with 14 meeting inclusion criteria (diagnosed 2014 – 2018). Median Ki-67 proliferative index was 25%. Two patients (14%) had a partial response to SSA therapy, five (36%) had stable disease, and seven (50%) had progressive disease. The estimated median PFS was 4.4 months (95% CI 2.9 – 24). Of the 7 patients with stable disease or partial response, the median time to progression was 8.7 months. Three patients had stable disease for greater than 9 months (24, 29 and 42 months, respectively). Overall survival was not estimable. There was no association of Ki-67 index with PFS based on a proportional hazards model. Conclusions: This is the first report on the efficacy of SSAs for G3 NETs. Although half of the patients in our series had at least stable disease, the PFS was modest at only 4.4 months. Given their favorable side-effect profile compared to cytotoxic chemotherapy, SSAs may present an attractive option to be further explored in a prospective fashion. We are presently updating this data by reassessing response using RECIST criteria.


2021 ◽  
Vol 39 (3_suppl) ◽  
pp. 366-366
Author(s):  
İzzet Dogan ◽  
Didem Tastekin ◽  
Senem Karabulut ◽  
Burak Sakar

366 Background: The study aimed to evaluate patients' outcomes and prognosis with metastatic gastrointestinal neuroendocrine tumors (mgNET) who treated temozolomide and capecitabine (CAPTEM). Methods: The data of forty-three patients were retrospectively evaluated. Clinicopathological features and treatment approaches were recorded. Kaplan-Meier analysis was used for overall survival (OS) and progression-free survival (PFS). Prognostic factors were assessed with Cox-regression analysis. Results: Median age was 59 (27-85) years. The number of male and female patients was 23 (%53.5) and 20 (%46.5), respectively. Pancreas (%51.2) was the most common site of the tumor. The number of patients with well- and poorly-differentiated mgNET was 38 (%88.4) and 5 (%11.6), respectively. The most common metastatic sites were liver (%62.8), lymph node (%58.1), and bone (%18.6). Eleven (%25.6) of the patients previously had undergone surgery, and some patients received radiotherapy (%9.5), chemotherapy (%19), and nuclear therapy (%9.3). Also, patients received octreotide (%86) or lanreotide (%14) with CAPTEM. In patients with well-differentiated mgNET, median PFS was 17.4 months, and disease control ratio %79.4 (%3-complete response, %38.2-partial response, and %38.2-stable response). No response observed in patients with poorly differianted mgNET, and the median PFS was calculated as 4.5 months. Grade 1-2 toxicity was observed in 34 (%79.1) of the patients, and grade 3-4 toxicity in 8 (%18.6). Four (%9.5) patients discontinued therapy for the toxicity. The most common toxicities were anemia (%37.2), thrombocytopenia (%25.6), and fatigue (%16.3). At a median follow-up of 33.8 (2.9-172.73) months, the ratio of five-years OS was %61. In multivariate analysis; gender (p=0.008), age (p=0.007), and Ki-67 levels (p=0.011) were a statistically significant for OS. However, the site of the tumor (p=0.186), number of metastatic sites (p=0.255), and type of somatostatin receptor ligand (p=0.903) were not. Conclusions: In the study, we showed that CAPTEM + somatostatin receptor ligands (octreotide or lanreotide) were effective and well-tolerated in patients with well-differentiated mgNET. But, it was not effective in patients with poorly-differentiated mgNET. Male gender, aged over 60 years, and tumor with a high level of Ki-67 were negative prognostic factors.


2012 ◽  
Vol 30 (15_suppl) ◽  
pp. e14598-e14598
Author(s):  
Juan Manuel O'Connor ◽  
Veronica Pesce ◽  
Guillermo Ariel Mendez ◽  
Claudia Bestani ◽  
Fabiana Marmissolle ◽  
...  

e14598 Background: Somatostatin receptor expression (SSTR), mainly subtypes 2 and 5, is a feature of well differentiated GEP-NETs. Such expression has a prognostic and predictive value for the use of somatostatin analogs.Ki 67, present during the cycle phases (G1, S, G2 y M) is a nuclear antigen associated with cell proliferation. The correlation between both clinical and pathological factors is under active investigation in patients with GEP-NETs. Methods: An analysis including 100 patients in the database of the Argentum Group was performed. Consecutive patients were included during the 2006-2007 period. In all cases, a centralized revision of the sample was conducted for diagnosis confirmation.The study of SSTR receptors in tissue and Ki67 was conducted using IHQ.The Kaplan-Meier method was used to analyse survival. Log-rank test was used for the comparative analysis of the variables of interest. Results: The expression of at least one of the SSTRs 2 (a) or 5 was found in 86% and 62% of cases respectivevly in this population. The univariate analysis showed significant differences in the expression of SSTR2 (a) but not in the expression of SSTR 5.The expression of the proliferative index (Ki 67) was associated with significant differences in relation to OS at 5 years, 84% (Ki 67 under or equal to 2%), 66% (Ki 67 between 3 and 15%) and 13% (Ki 67 over 15%). The OS at 5 years in patients with SSTR 2/5 positive and Ki 67 under 2% was 86%, 64% in pts. with SSTR 2/5 positive and Ki 67 over 2% and 20 % in pts. with SSTR 2/5 negative, independent Ki 67 (p .0023). Conclusions: The expression of at least one of the SSTRs 2 (a) or 5 was found in 86% and 62% of cases respectivevly in this population. In the population with GEP-NETs under study, a subgroup of patients with a better prognosis was identified in association with the expression of SSTR 2/5 and Ki67 below 2%. The assessment of SSTR 2(a) and 5 in tissues, together with the study of the proliferative index are a useful tool for prognosis assessment in these patients.


2021 ◽  
Vol 13 ◽  
pp. 175883592110180
Author(s):  
Satya Das ◽  
Arvind Dasari

Gastroenteropancreatic (GEP) neuroendocrine tumors (NETs) represent the most common subtype of NETs. The incidence of all NETs, and specifically GEP NETs, has risen exponentially over the last three decades. Only within the past several years have these tumors been appropriately classified, allowing for meaningful drug development. Broadly, some of the most exciting drug classes being developed for patients with well-differentiated GEP NETs include newer types of peptide receptor radionuclide therapy (PRRT) or combinations which increase the potency of lutetium-177 (177Lu)-Dotatate, novel multi-target receptor tyrosine kinase inhibitors (RTKIs) and immunotherapy modalities, beyond checkpoint inhibitors, which seek to unleash the immune system against NETs. Specifically looking at newer types of PRRT, somatostatin receptor antagonists and alpha-emitter radionuclides each have demonstrated the ability to elicit greater DNA damage than 177Lu-Dotatate in preclinical models. Early clinical experiences with each of these agents suggest they may be more cytotoxic than 177Lu-Dotatate. Other approaches seeking to build upon the DNA damage created by 177Lu-Dotatate include combinations of PRRT with radiosensitizers such as heat shock protein 90 inhibitors, hedgehog inhibitors, chemotherapy combinations, and triapine. Many of these combinations have just begun to be tested clinically. With regards to novel RTKIs, some of the ones which have demonstrated potent cytoreductive potential include cabozantinib and lenvatinib. Other RTKIs which are further along the clinical development spectrum and have demonstrated benefit in randomized trials include surufatinib and pazopanib. And though single-agent immune checkpoint inhibitors have not demonstrated significant anti-tumor activity in patients with GEP NETs, outside of certain biomarker selected subsets, somatostatin receptor-directed chimeric antigen receptor (CAR) T cells and vaccines such as SurVaxM, which targets survivin, represent two means through which NET-directed immunity may be modulated. The potential of these agents, if clinically realized, will likely improve outcomes for patients with well-differentiated GEP NETs.


2021 ◽  
Vol 12 ◽  
Author(s):  
Mayank Patel ◽  
Isabel Tena ◽  
Abhishek Jha ◽  
David Taieb ◽  
Karel Pacak

Neuroendocrine tumors overexpress somatostatin receptors, which serve as important and unique therapeutic targets for well-differentiated advanced disease. This overexpression is a well-established finding in gastroenteropancreatic neuroendocrine tumors which has guided new medical therapies in the administration of somatostatin analogs, both “cold”, particularly octreotide and lanreotide, and “hot” analogs, chelated to radiolabeled isotopes. The binding of these analogs to somatostatin receptors effectively suppresses excess hormone secretion and tumor cell proliferation, leading to stabilization, and in some cases, tumor shrinkage. Radioisotope-labeled somatostatin analogs are utilized for both tumor localization and peptide radionuclide therapy, with 68Ga-DOTATATE and 177Lu-DOTATATE respectively. Benign and malignant pheochromocytomas and paragangliomas also overexpress somatostatin receptors, irrespective of embryological origin. The pattern of somatostatin receptor overexpression is more prominent in succinate dehydrogenase subunit B gene mutation, which is more aggressive than other subgroups of this disease. While the Food and Drug Administration has approved the use of 68Ga-DOTATATE as a radiopharmaceutical for somatostatin receptor imaging, the use of its radiotherapeutic counterpart still needs approval beyond gastroenteropancreatic neuroendocrine tumors. Thus, patients with pheochromocytoma and paraganglioma, especially those with inoperable or metastatic diseases, depend on the clinical trials of somatostatin analogs. The review summarizes the advances in the utilization of somatostatin receptor for diagnostic and therapeutic approaches in the neuroendocrine tumor subset of pheochromocytoma and paraganglioma; we hope to provide a positive perspective in using these receptors as targets for treatment in this rare condition.


2020 ◽  
Vol 38 (15_suppl) ◽  
pp. TPS4660-TPS4660
Author(s):  
Aman Chauhan ◽  
Charles Kunos ◽  
Riham El Khouli ◽  
Jill Kolesar ◽  
Heidi Weiss ◽  
...  

TPS4660 Background: Radiolabeled somatostatin analogues provide a means of delivering targeted radiation with a high therapeutic index to NETs that express somatostatin receptors (SSTRs). Radiolabeled somatostatin analogue Lutetium Lu 177 Dotatate (Lutathera) is a beta-emitting radionuclide, recently FDA approved for use in SSTR positive gastroenteropancreatic neuroendocrine tumors (GEPNETS) in the US based on the NETTER-1 Phase III trial. Despite favorable PFS and safety profile, the drug has limited cytoreductive capability with a 17% ORR. We hypothesize that addition of an effective radiation sensitizer could help improve antitumor activity of Lutathera. Ribonucleotide reductase (RNR) is the only enzyme responsible for conversion of ribonucleoside diphosphate to deoxyribonucleotide diphosphate (dNDP), the key building blocks for DNA synthesis. Radiation is a potent inducer of DNA double-strand breaks (DSBs), and RNR is the rate-limiting enzyme in the repair of DNA in this setting. Triapine is an inhibitor of RNR. This study will test the hypothesis that radiation sensitizer triapine can be safely combined with peptide receptor radionuclide therapy and ultimately may improve antitumor activity of Lutetium Lu 177 Dotatate. Methods: This study is an investigator initiated, NCI sponsored, multicenter phase 1 trial of triapine and Lutetium Lu 177 Dotatate in well-differentiated somatostatin receptor-positive gastroenteropancreatic neuroendocrine tumor (GEP-NETs) after the failure of at least one line of prior systemic cancer treatment. A total of 29 patients will be enrolled in the dose escalation with help of Bayesian optimal interval design (BOIN) and dose expansion cohorts. The study will be open through the NCI ETCTN (National Cancer Institute Experimental Therapeutics Clinical Trials Network) program. Patients will be treated with 177 lutetium dotatate in combination with triapine. Triapine will be administered orally (100 mg once a day starting dose) from D1-14 with each dose of PRRT [200 mCi]. Primary endpoint is to evaluate recommended phase II dose (RP2D). Secondary endpoints are to evaluate safety, pharmacokinetics, and clinical activity (ORR and PFS). We are also evaluating NETEST, a novel blood based test that evaluates levels of 51 neuroendocrine tumor gene transcripts. In addition, the study will correlate clinical outcome with baseline somatostatin receptor density, somatic tumor mutations and germline mutations. Clinical trial information: 04234568 .


2019 ◽  
Vol 37 (15_suppl) ◽  
pp. e15696-e15696
Author(s):  
Salman Rafi Punekar ◽  
Lena Masri-Lavine ◽  
Cristina Hajdu ◽  
Elliot Newman ◽  
Daniel Jacob Becker

e15696 Background: Small studies suggest that a new pathologic entity of high-grade (by Ki-67 or mitotic index) well-differentiated (by histologic features) neuroendocrine tumors (NETs) exist throughout the GI tract, but the prognosis and characteristics of affected patients are unknown. We sought to further characterize the prognosis and demographics of patients with high-grade (HG) well-differentiated (WD) colorectal NET. Materials and Methods: We used the Surveillance Epidemiology and End Results (SEER) database to study patients with NETs of the colon and rectum diagnosed from 2000 to 2015. We identified patient demographics, clinical and tumor characteristics, and studied associations with tumor grade. We compared overall survival (OS) between patients with low-grade (LG)(grade 1-2) well-differentiated (ICD-0-3 = carcinoid), high-grade (grade 3-4) well-differentiated, and high-grade poorly-differentiated NETs (ICD-0-3 = small cell neuroendocrine). We used logistic regression to detect associations with grade and Cox proportional hazards models to examine predictors of survival. Results: We identified 5,894 cases with colorectal carcinoid tumor (5780 [98.1%] LG and 114 [1.9%] HG); the cohort was 68% white, 48% male, and had a median age of 54. Patients diagnosed with HG carcinoid tumors were more likely to be of older age (OR 2.23; 95% CI 1.19-4.19 for age 60-69 vs < 50) and unmarried (OR 1.56; 95% CI 1.02-2.38), and less likely to be diagnosed after 2010 (OR 0.09; 95% CI 0.06-0.15). OS for patients with HG carcinoids (median 36 m; 95% CI 13-92) fell in between OS for those with HG small cell NETs (median 7 m; 95% CI 6-8), and LG carcinoid tumor (median not reached, > 120 m). Among patients with carcinoid tumors, black patients (HR 1.31; 95% CI 1.03-1.67, older patients (HR 3.60; 95% CI 2.50-5.19 for age 60-69 vs < 50), unmarried patients (HR 1.52; 95% CI 1.24-1.87), and those with HG features (HR 3.85; 95% CI 2.88-5.15) had worse survival. Conclusions: We defined a subset of high-grade well-differentiated NETs, more commonly diagnosed in older, unmarried patients, with a prognosis between that of high grade small cell NETs and low grade carcinoid tumors. Our analysis adds the first national registry study to the literature in support of a new classification of non-pancreatic high-grade well differentiated NETs.


Cancers ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1516
Author(s):  
Thorsten Derlin ◽  
Natalia Bogdanova ◽  
Fiona Ohlendorf ◽  
Dhanya Ramachandran ◽  
Rudolf A. Werner ◽  
...  

Background: We aimed to characterize γ-H2AX and 53BP1 foci formation in patients receiving somatostatin receptor-targeted radioligand therapy, and explored its role for predicting treatment-related hematotoxicity, and treatment response. Methods: A prospective analysis of double-strand break (DSB) markers was performed in 21 patients with advanced gastroenteropancreatic neuroendocrine tumors. γ-H2AX and 53BP1 foci formation were evaluated in peripheral blood lymphocytes (PBLs) at baseline, +1 h and +24 h after administration of 7.4 GBq (177Lu)Lu-DOTA-TATE. Hematotoxicity was evaluated using standard hematology. Therapy response was assessed using (68Ga)Ga-DOTA-TATE PET/CT before enrollment and after 2 cycles of PRRT according to the volumetric modification of RECIST 1.1. Results: DSB marker kinetics were heterogeneous among patients. Subclinical hematotoxicity was associated with γ-H2AX and 53BP1 foci formation (e.g., change in platelet count vs change in γ-H2AX+ cells between baseline and +1 h (r = −0.6080; p = 0.0045). Patients showing early development of new metastases had less γ-H2AX (p = 0.0125) and less 53BP1 foci per cell at +1 h (p = 0.0289), and demonstrated a distinct kinetic pattern with an absence of DSB marker decrease at +24 h (γ-H2AX: p = 0.0025; 53BP1: p = 0.0008). Conclusions: Assessment of γ-H2AX and 53BP1 foci formation in PBLs of patients receiving radioligand therapy may hold promise for predicting subclinical hematotoxicity and early treatment response.


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