Preliminary diagnostic performance of [68Ga ]-NeoBOMB1 in patients with gastrin-releasing peptide receptor-positive breast, prostate, colorectal or lung tumors (NeoFIND)

346 Objectives: Gastrin-releasing peptide receptor (GRPR) is a potential target for imaging and treatment in patients suffering from a variety of tumors. NeoBOMB1 is a novel DOTA-coupled high-affinity GRPR antagonist with excellent in vivo stability. [68Ga]-NeoBOMB1 was well tolerated and had variable tumor-specific uptake in patients with advanced gastrointestinal stromal tumors in a previous phase 1/2a study (MITIGATE; EudraCT 2016-002053-38).1 The aim of NeoFIND was to characterize the targeting properties of [68Ga]-NeoBOMB1 in patients with other malignancies known to overexpress GRPR. Methods: NeoFIND (NCT03724253) was an open-label, multicenter, phase 2 study in adults with luminal breast cancer, adenocarcinoma of the prostate, colorectal carcinoma, non-small-cell lung cancer or small-cell lung cancer who had at least one malignant lesion and a biopsy taken within 6 months of enrollment. Eligible patients with metastatic breast or prostate cancer could choose to enter a whole-body dosimetry subgroup. Patients received a single intravenous dose of [68Ga]-NeoBOMB1 (3 MBq/kg; maximum 250 MBq; minimum 150 MBq) and underwent static PET/CT imaging. Primary outcome measures included tumor distribution and secondary outcomes included safety and whole-body dosimetry. Results: The 19 patients enrolled had a median age of 66.0 years (range, 51-81) and eight (42%) were female. All patients had advanced disease (stage IV, n = 16 [84%]; stage IIIA-C, n = 3 [16%]) and 68% of patients had received previous systemic cancer therapy. Immunohistochemical analyses revealed GRPR overexpression in biopsies from all patients, taken either from primary tumors (47%) or metastases (53%). PET imaging detected uptake of [68Ga]-NeoBOMB1 in at least one primary or metastatic lesion in 17/19 patients (Table). In 9 patients (47%), at least half of the primary or metastatic lesions that were detected with conventional imaging (e.g. MRI, [18F]-fluorodeoxyglucose PET) were also detected with [68Ga]-NeoBOMB1. Two serious adverse events and 25 adverse events were reported during the study and none of these were considered related to [68Ga]-NeoBOMB1. Two patients with breast cancer entered the dosimetry subgroup and their effective whole-body doses were 0.0203 and 0.0151 mSv/MBq, respectively. Conclusions: [68Ga]-NeoBOMB1 uptake allowed detection of primary and metastatic lesions in patients with different tumor types, although tumor-specific uptake was variable and warrants further investigation. [68Ga]-NeoBOMB1 was well tolerated, with no related adverse events, consistent with the safety profile in previous studies. Whole-body dosimetry data were consistent with previous results in patients with gastrointestinal stromal tumors.1 The findings support further clinical development of NeoB (formerly known as NeoBOMB1) in a theragnostic approach using [68Ga]-NeoB to identify patients with GRPR-positive malignancies who may be considered for subsequent therapy with [177Lu]-NeoB. References: 1. Gruber L et al. Eur J Nucl Med Mol Imaging 2019;46 Suppl 1:S68 Funding: This study was funded by Advanced Accelerator Applications (AAA), a Novartis company. AAA develops and markets nuclear medicines for cancer.