Optimization and scale-up of [68Ga]Ga-FAPI-46 production on a Modular-Lab PharmTracer platform for clinical application.

Background: Due to the increasing application of the fibroblast activation protein (FAP) targeting radiotracer [68Ga]Ga-FAPI-46 in cancer diagnostics by PET/CT, there is a need for a convenient way for routine production of high activities of this tracer. The aim of the current work is the optimization and scale-up of an automated method for [68Ga]Ga-FAPI-46 production on a PharmTracer module using two GalliaPharm generators. Results: Several labeling conditions were evaluated and the best results were obtained with 40 μg of precursor, 3 mg ascorbic acid as anti-radiolysis agent, 0.4 M sodium acetate buffer pH 4.5 and 15 min heating at 95 °C. Furthermore, Vitamin C was added to the final formulation as stabilizer to ensure product quality in a time frame of 3 h after the end of synthesis. The evaluation of 43 routine syntheses of [68Ga]Ga-FAPI-46 resulted in a decay-corrected yield of 91.1 ± 3.4 % and radiochemical purity of 99.8 ± 0.3 % as determined by radio-HPLC. All the quality control parameters were in accordance with specifications. Conclusions: In conclusion, we developed an efficient and robust method able to provide multiple doses of [68Ga]Ga-FAPI-46, enabling a better response to the clinical need for this radiopharmaceutical.