Optimized and Automated Production of [18F]FFNP for Progesterone Receptor PET Imaging

Abstract [18F]FFNP is a promising investigational radiopharmaceutical for PET imaging of progesterone receptor (PR) expression in breast cancer. [18F]FFNP PET imaging enables noninvasive assessment of PR expression and serves as a valuable diagnostic tool for determining the functional endocrine status of ER+ breast tumors to guide endocrine therapy. In this study, we report a robust and fully automated radiosynthesis of [18F]FFNP using a commercially available radiosynthesizer. The ratio of the mesylate precursor to the K2.2.2/K2CO3 complex was found to be critical for optimizing radiochemical yield. The optimized and automated radiosynthesis process was completed within 50 min and successfully passed three consecutive validation runs, producing [18F]FFNP activity in 19.52–23.91% decay-corrected radiochemical yields at the end of synthesis. Approximately 215–265 mCi (7.96–9.81 GBq) of [18F]FFNP activity was obtained with high radiochemical purity (99.65–99.72%) and molar activity (16.83–37.40 Ci/μmol [623–1384 GBq/μmol]) in our cGMP-compliant PET Radiochemistry facility. All drug product specifications passed quality control (QC) testing and met the requirements for clinical investigational use.