Development and evaluation of improved in-house procedure for radiolabelling of theranostic agent [177Lu]Lu-PSMA-617

Abstract Background Recent focus in the treatment of prostate cancer is directed towards the development and application of theranostic agents such as [ 177 Lu]Lu-PSMA-617. It combines a PSMA-specific peptidomimetic with a therapeutical radionuclide 177 Lu and it is used in radioligand therapy that selectively delivers ionizing radiation into tumor cells. This study reports the automated radiosynthesis and quality control of an in-house [ 177 Lu]Lu-PSMA-617 preparation and a direct comparison of its properties with the reference product (Pluvicto ® ). Results The radiopharmaceutical was obtained with > 95% radiochemical purity and > 96% radiochemical yield. The addition of ethanol improved radiochemical yield. The obtained product maintained > 98% radiochemical purity for up to 72 h in isotonic saline and human serum at 25 °C and 37 °C. The use of carrier-added 177 Lu for the in-house product and non-carrier-added 177 Lu for the reference product was confirmed by ICP-MS and gamma spectrometry methods. Conclusion Comparative quality control demonstrated generally equivalent quality attributes of in-house prepared product and the reference product, supporting in-house product suitability for routine clinical application at activities up to 7.4 GBq. This experiment showed that in-house production of 177 Lu-labeled theranostics is cost-effective method and can be automatized resulting in high quality and efficient production.