Overexpression of urokinase-type plasminogen activator receptors (uPAR) represents an established biomarker for aggressiveness in most common malignant diseases, including breast (BC), prostate (PC) and urinary bladder cancer (UBC) and is therefore an important target for new cancer therapeutic and diagnostic strategies. In the study, uPAR Positron Emission Tomography (PET) imaging using a (68)Ga-labelled version of the uPAR targeting peptide (AE105) was investigated in a group of patients with BC, PC and UBC. The aim of this first-in-humans, Phase I, clinical trial was to investigate safety and biodistribution in normal tissues and uptake in tumor lesions.
Ten patients (6 PC, 2 BC and 2 UBC) received a single intravenous dose of (68)Ga-NOTA-AE105 (154 + 59 MBq; range 48-208 MBq). The biodistribution and radiation dosimetry were assessed by serial PET/CT scans (10 minutes, 1 and 2 hours p.i.). Safety assessment included measurements of vital signs with regular intervals during the imaging sessions and laboratory blood screening tests performed before and after injection. In a subgroup of patients, the in vivo stability of (68)Ga-NOTA-AE105 was determined in collected blood and urine. PET images were visually analyzed for visible tumor uptake of (68)Ga-NOTA-AE105 and Standardized Uptake Values (SUVs) were obtained from tumor lesions by manually drawing volumes of interest (VOIs) in the malignant tissue.
No adverse events or clinically detectable pharmacologic effects were found. The radioligand exhibited good in vivo stability and fast clearance from tissue compartments primarily by renal excretion. The effective dose was 0.015 mSv/MBq leading to a radiation burden of 3 mSv when using the clinical target dose of 200 MBq. In addition, radioligand accumulation was seen in primary tumor lesions as well as in metastases.
This first-in-humans, Phase 1 clinical trial demonstrates the safe use and clinical potential of (68)Ga-NOTA-AE105 as a new radioligand for uPAR PET imaging in cancer patients.
Journal of nuclear medicine : official publication, Society of Nuclear Medicine. 2016 Sep 08 [Epub ahead of print]
Dorthe Skovgaard, Morten Persson, Malene Brandt-Larsen, Camilla Christensen, Jacob Madsen, Thomas Levin Klausen, Soeren Holm, Flemming Littrup Andersen, Annika Loft, Anne Kiil Berthelsen, Helle Pappot, Klaus Brasso, Niels Kroman, Liselotte Hoejgaard, Andreas Kjaer
Department of Clinical Physiology, Nuclear Medicine & PET and Cluster for Molecular Imaging, Rigsho;, Curasight, Denmark;, Department of Oncology, Rigshospitalet, Denmark;, Copenhagen Prostate Cancer Center, Department of Urology, Abdominal Centre, Rigshospitalet;, Department of Plastic Surgery, Breast Surgery and Burns Treatment, Rigshospitalet, Denmark.