The aim of this project was to create and validate a generator-based theranostic compound for urologic oncology targeting PSMA^[2] and utilising the beta-emitting isotope rhenium-188 (¹⁸⁸Re).

The outcomes from the research project – which included a pre-clinical and first-in-human evaluation – have been published in the latest issue of the Journal of Nuclear Medicine.^[3]

The project has resulted in new intellectual property and a translational data package that may be used to advance this compound into a Phase I clinical trial. Telix is now progressing discussions regarding the further development of the compound with the goal of spinning-out this program into an innovative new company, in partnership with leading academic researchers, to further advance the program into the clinic.

The technology platform consists of a targeting agent that can be conjugated with a true-theranostic pair of radioisotopes: ^99mTc (technetium-99m) for imaging and ¹⁸⁸Re for therapeutic use. ¹⁸⁸Re is a highly differentiated therapeutic beta-emitting isotope that is regarded as an attractive option for radiopharmaceutical therapy applications due to its high energy output over a 16.9 hour half-life and its ability to be reliably produced at the point of care via a generator.^[4]  

Radiopharmaceuticals based on more common therapeutic radioisotopes (on market or in development) such as lutetium-177 (¹⁷⁷Lu) and actinium-225 (²²⁵Ac), are typically centrally manufactured in facilities that require significant investment and infrastructure to operate, such as reactors or cyclotrons. The ¹⁸⁸Re-based approach decentralises drug manufacturing and may be suitable for a wide variety of markets and clinical applications where radiopharmaceutical manufacturing infrastructure or supply chain is limited.

Dr Christian Behrenbruch, Group CEO and Managing Director of Telix, said, "This collaboration has demonstrated the benefit of a purely generator-based theranostic deployment model. Generator-based therapeutic radiopharmaceuticals have the potential to be produced "on-demand" in any nuclear pharmacy, and therefore have the potential to greatly expand access to therapy."

The lead researcher on this project; Professor Dr Frederik Giesel of Universitätsklinikum Düsseldorf, Department of Nuclear Medicine and Telix Scientific Advisory Board member, said, "Rhenium-188 is a high potential generator-based therapeutic nuclide which can provide access to on-demand radiolabelling at reasonable costs. Our initial research has demonstrated that the product is stable after radiolabelling, with good tumour uptake and low uptake in non-target organs. These are all favourable characteristics for progressing the theranostic tandem of ^99mTc and ¹⁸⁸Re in imaging and therapy."