Abstract Library

#4669 Efficacy and safety of [177Lu]Lu-edotreotide vs. everolimus in patients with grade 1 or grade 2 gastroenteropancreatic neuroendocrine tumours: COMPETE phase 3 trial

Introduction: Patients with metastatic gastroenteropancreatic neuroendocrine tumours (GEP-NET) have limited therapeutic options.

Conference:

Presenting Author:

Authors: Capdevila J, Amthauer H, Ansquer C, Deshayes E, Garcia-Carbonero R,

Keywords: radiopharmaceutical therapy, neuroendocrine tumour, [177Lu]Lu-edotreotide, progression-free survival, gastroenteropancreatic,

#4666 Merkel cell neuroendocrine carcinoma of the skin: High response rates to short course palliative radiotherapy – Typical clinical scenarios

Introduction: Merkel cell carcinomas (MCC) are a rare, aggressive skin neuroendocrine carcinomas, with peak incidence in the elderly. MCC often presents as a firm, red/purple painless nodule with a short history of increasing size. Surgery is considered the 1st line treatment but elderly patients, in particular, have comorbidities which may preclude radical surgery requiring reconstruction. In advanced MCC, immunotherapy (IO) is 1st line systemic treatment. Chemotherapy is used 2nd line or if contraindications for IO but can be challenging in an elderly population. There may be an emerging role for PRRT due to the presence of somatostatin receptors on MCC. Radiotherapy (RT) can be used for non-surgical candidates, or those with unresectable or metastatic disease. Adjuvant post-operative irradiation (PORT) may provide additional benefit in risk reduction and improves local control.

Conference:

Presenting Author:

Authors: Saunders E, Sizer B, Collins J, Skelly R, Srinivasan G,

Keywords: Merkel cell, skin, radiotherapy,

#4630 Radiolabelled somatostatin receptor (SSTR) antagonist vs. agonist for peptide receptor radionuclide therapy (PPRT) in patients with SSTR positive neuroendocrine tumours – A retrospective basket study

Introduction: PRRT with lutetium-177 labelled somatostatin receptor (SSTR) agonists ([177Lu]Lu-DOTATATE or [177Lu]Lu-DOTATOC (177Lu-TOC) has limited response rate and durability. The SSTR antagonist [177Lu]Lu-DOTA-JR11 (177Lu-JR11) offers potentially increased tumour doses with better efficacy.

Conference:

Presenting Author: Eigler C

Authors: Eigler C, Mushaweh A, McDougall L, Bauman A, Christ E,

Keywords: Somatostatin Receptor, Neuroendocrine Tumour, DOTA-JR11, DOTA-TOC, Peptide Receptor Radionuclide Therapy,

#4619 Targeted beta- plus auger and conversion electron therapy with terbium-161 labelled somatostatin receptor antagonist DOTA-LM3 – BETA plus phase 0 study

Introduction: Radioligand therapy with lutetium-177 labelled somatostatin receptor (SSTR) agonists (177Lu-DOTATATE or 177Lu-DOTATOC) showed limited response rate and durability. The novel SSTR antagonist DOTA-LM3 labelled with terbium-161, which co-emits conversion and Auger electrons in addition to β- particles, potentially increasing tumour doses and offering a more effective treatment for micro metastases.

Conference:

Presenting Author: Fricke J

Authors: Fricke J, Westerbergh F, McDougall L, Christ E, Nicolas G,

Keywords: Radionuclide therapy, PRRT, Auger electrons, Conversion electrons, Terbium-161, radiolabelled somatostatin antagonist, neuroendocrine tumour,

#4601 Pembrolizumab combined with cisplatin or carboplatin and etoposide in treatment naïve advanced Merkel cell carcinoma (MCC): The phase II PANDORA Trial

Introduction: MCC is a rare and aggressive skin neuroendocrine tumour with high metastatic potential and mortality. Therapeutic options in metastatic/unresectable MCC are based on immunotherapy or platinum-based chemotherapy. However, a subgroup of patients (pts) has primary immunoresistance disease, so it would be important discover active upfront combinations. PANDORA trial [NCT 06086288] is an open-label, multicentre, single-arm phase II trial evaluating the activity and safety of pembrolizumab (PEM) combined with platinum-based chemotherapy as 1st line treatment in pts with metastatic, unresectable or recurrence MCC. Supported in part by a research grant from Investigator-Initiated Studies Program of MSD.

Conference:

Presenting Author: Oldani S

Authors: Oldani S, Morano F, Cingarlini S, Di Giacomo A, Borghesani M,

Keywords: Pembrolizumab, clinical trial, Merkel cell carcinoma, chemio-immunotherapy,