Radiopharmaceutical production and stability studies of rhPSMA-7.3 on a Siemens Explora GN Synthesis Module

1128 Objectives: The purpose of this work was to implement the production of rhPSMA-7.3 F 18 on a Siemens GN Explora module and evaluate drug stability over a 10-hour time frame. Radiohybrid ligands are a new class of theranostic prostate-specific membrane antigen (PSMA)-targeting agents which can be radiolabeled with F-18 or a radiometal. In this study we radiolabeled the trifluoroacetate precursor with F-18 at room temperature followed by solid-phase purification. Each batch was prepared targeting a radioactive concentration at end of synthesis (EOS) of approximately 100 mCi/mL. Typical final volumes were in the 25mL range. Methods: The stability of rhPSMA-7.3 F 18 was assessed on a total of 9 vials (3 different vial manufacturers). Quality control testing of the final product vial was conducted at EOS. Each vial was then stored inverted with drug product at controlled room temperature (CRT). Stability indicating tests were performed at least 10 hours post-EOS. Each batch was analyzed for long lived radionuclides (radionuclidic purity). Results: All quality control testing requirements were satisfied at both timepoints. As summarized in the Table, the quality of the product at EOS was equivalent to that at expiry (10 hrs). The results demonstrate the stability of the rhPSMA-7.3 F 18 formulation in each of the three manufacturer vials filled with drug product at specific concentrations >100 mCi/mL over a period of 10 hours stored at CRT. Conclusions: The observed equivalency in the quality of the drug product over a significant time frame indicates that the formulation is stable and supports commercialization of rhPSMA-7.3 F 18 with potential to distribute over significant distances.