Good manufacturing procedure production of [18F]SynVesT-1, a radioligand for in vivo positron emission tomography imaging of synaptic vesicle glycoprotein 2A

Abstract

[¹⁸F]SynVesT-1 (also known as [¹⁸F]SDM-8 or [¹⁸F]MNI-1126) is a potent and selective synaptic vesicle glycoprotein 2 (SV2A) positron emission tomography (PET) imaging agent. In order to fulfill the increasing clinical demand of an ¹⁸F-labeled SV2A PET ligand, we have developed a fully automated procedure to provide a sterile and pyrogen-free good manufacturing procedure (GMP)-compliant product of [¹⁸F]SynVesT-1 suitable for clinical studies in humans. [¹⁸F]SynVesT-1 is synthesized via a rapid copper-mediated radiofluorination protocol. The procedure was developed and established on a commercially available module, TracerMaker (ScanSys Laboratorieteknik ApS, Copenhagen, Denmark), a synthesis platform originally developed to conduct carbon-11 radiochemistry. From ~130 GBq (end-of-bombardment), our newly developed procedure enabled us to prepare [¹⁸F]SynVesT-1 in an isolated radioactivity yield of 14,220 ± 800 MBq (n = 3), which corresponds to a radiochemical yield (RCY) of 19.5 ± 0.5%. The radiochemical purity (RCP) and enantiomeric purity of each of the final formulated batches exceeded 98%. The overall synthesis time was 90 min and the molar activity was 330 ± 60 GBq/μmol (8.9 ± 1.6 Ci/μmol). The produced [¹⁸F]SynVesT-1 was stable over 8 h at room temperature and is suitable for in vivo PET imaging studies in human subjects.