New Fully Automated Preparation of High Apparent Molar Activity 68 Ga-FAPI-46 on a Trasis AiO Platform

Chiara Da Pieve, Marta Costa Braga, David R Turton, Frank A Valla, Pinar Cakmak, Karl-Heinz Plate, Gabriela Kramer-Marek

Abstract:A large number of applications for fibroblast activation protein inhibitors (FAPI)-based PET agents have been evaluated in conditions ranging from cancer to non-malignant diseases such as myocardial infarction. In particular, ⁶⁸Ga-FAPI-46 was reported to have a high specificity and affinity for FAP-expressing cells, a fast and high accumulation in tumor lesions/injuries together with a fast body clearance when investigated in vivo. Due to the increasing interest in the use of the agent both preclinically and clinically, we developed an automated synthesis for the production of ⁶⁸Ga-FAPI-46 on a Trasis AiO platform. The new synthetic procedure, which included the processing of the generator eluate using a strong cation exchange resin and a final purification step through an HLB followed by a QMA cartridge, yielded ⁶⁸Ga-FAPI-46 with high radiochemical purity (>98%) and apparent molar activity (271.1 ± 105.6 MBq/nmol). Additionally, the in vitro and in vivo properties of the product were assessed on glioblastoma cells and mouse model. Although developed for the preparation of ⁶⁸Ga-FAPI-46 for preclinical use, our method can be adapted for clinical production as a reliable alternative to the manual (i.e., cold kit) or modular systems preparations already described in the literature.