Abstract Library

#4417 Efficacy of immune checkpoint inhibitors (ICI) in patients with advanced pancreatic NETs displaying high TMB and MMR alterations following treatment with alkylating agents

Introduction: Alkylating chemotherapy (ALK) is frequently used in patients with PanNETs. It may favour grade progression and acquisition of a hypermutator phenotype associated with frequent alterations of the MMR genes, suggesting a potential benefit of ICI.

Conference:

Presenting Author:

Authors: de Mestier L, Apostolidis L, Koumarianou A, Hernando Cubero J, Riechelmann R,

Keywords: immune checkpoint inhibitor, immunotherapy, hypermutagenicity, alkylating agents, tumour mutational burden, mismatch repair,

#4392 Updated results of first-line chemotherapy combined with an immune checkpoint inhibitor for advanced extrapulmonary neuroendocrine carcinoma: A single arm, phase II study

Introduction: NEC is a rare, aggressive cancer with limited response to standard first-line chemo (etoposide + cisplatin/carboplatin, EP/EC).

Conference:

Presenting Author:

Authors: Cao D, Li X, Li R, Wang X, Yang Y,

Keywords: neuroendocrine carcinoma, First-line, chemotherapy, camrelizumab,

#4291 Novel genomic score predicts survival with immune checkpoint blockade in neuroendocrine neoplasms

Introduction: Immune checkpoint inhibition (ICI) has activity in Grade 3 (G3) neuroendocrine neoplasms (NENs) but predictive biomarkers of overall survival (OS) are currently lacking.

Conference:

Presenting Author:

Authors: Brar T, Sukrithan V, Le D, Xu M, Olowookere C,

Keywords: Neuroendocrine Neoplasm, Immunotherapy, Ipilimumab, Nivolumab, Immune checkpoint inhibitor, biomarker, genomic score,

#4289 Temozolomide-associated hypermutation and response to immunotherapy in advanced pulmonary neuroendocrine tumours

Introduction: Temozolomide (TMZ) cytotoxicity depends on an intact DNA mismatch repair (MMR) pathway and low levels of O6-methylguanine DNA methyltransferase (MGMT). However, absence of MGMT-mediated repair coupled with defective MMR (dMMR) may lead to enrichment of C:G to A:T transitions throughout the genome, a marked increase in tumour mutational burden (TMB), and loss of TMZ-induced cytotoxicity. This resistance mechanism is called TMZ-associated hypermutation (TAH). Theoretically, this effect could lead to sensitivity to checkpoint inhibitor immunotherapy.

Conference:

Presenting Author: Buikhuisen W

Authors: Buikhuisen W, Badrising S, Moonen L, Derks J, Monkhorst K,

Keywords: Pulmonary NET, whole genome sequencing, temozolomide signature, immunotherapy,

#4228 Evaluation of the impact of indoleamine 2,3-deoxygenase (IDO) enzyme activity in neuroendocrine tumors (NETs)

Introduction: Indoleamine 2,3-deoxygenase (IDO) enzyme, by inducing L-tryptophan (Trp) depletion and L-kynurenine (kyn) accumulation, contributes to the formation of an immunosuppressive microenvironment. Some studies highlighted that patient with cancer in treatment with immune checkpoint inhibitors (ICI) and with low Kyn/Trp values showed a better PFS and OS, but there are no data for NETs.

Conference:

Presenting Author: Mancini C

Authors: Mancini C, Mazzilli R, Zamponi V, Motta C, Salerno G,

Keywords: neuroendocrine tumor, IDO enzyme, Kyn/Trp ratio, immunotherapy,