[F-18]siPSMA and [F-18]siTATE:

a pair of SiFA-based ligands ready to compete with the clinically established Ga-68 ligands.

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​​​F-18 is ready to compete with Ga-68

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​The development of theranostic radiohybrid PSMA inhibitors ​(rhPSMAs) by A.Wurzer and H.J.Wester at the Institute for Pharmaceutical Radiochemistry, Technical University Munich (TUM) and the subsequently clinical evaluation of [F-18]rhPSMAs by M. Eiber and colleagues at the Department of Nuclear Medicine (TUM) demonstrated for the very first time that ​an F-18-labeled silicone fluorine acceptor ​based radiopharmaceutical ​is stable against defluorination in-vivo and​, ​​if carefully designed, can ​​show ​ pharmacokinetics suitable for PET imaging even at early time points ​after injection. ​​Due to the​ outstanding labeling and imaging characteristics, [F-18]rhPSMA are being clinically developed by Blueearth Diagnostics (UK). Based on this initial success story, ​a series of purely diagnostic [F-18]siPSMA inhibitors have been developed by the same group​.

In addition, an automated process has been developed ​allowing to produce F-18-labeled SiFA-cinjugated radiopharmaceuticals in <1000sec (from end of bombardment to end of production/completed formulation). The process was established on a cassette system comprising of two stopcock manifolds. 

Moreover, ​F-18-labeled SiFA-conjugated ​ocreotate, named ​[F-18]SiFAlin-TATE (siTATE), has been successfully ​compared with​ [Ga-68]DOTA-TOC ​in 13 patients with NET. The authors concluded that ​the favorable characteristics of [F-18]SiFAlin-TATE, the ​simple labeling procedure, and the promising clinical performance enable improved logistics and diagnostic possibilities for PET imaging of NET. ​

In summary, and taking into accout that additional SiFA-peptides are being currently evaluated, we can conclude that the number of clinically revevant, SiFA-based F-18-labeled peptide and peptide-like radiopharmaceuticals will rapidly grow. The ease of production of F-18-labeled SiFA-conjugated radiopharmaceuticals will make them   ​enormously competitive. It seems that the time ​has come ​to take a close look whether and to what extend F-18 can substitute Ga-68 in the rapidly-growing field ​of theranostics. ​

References:    

siPSMA: Di Carlo D. et al. Eur J Nucl Med Mol Imaging (2019) 46 (Suppl 1): S16 (

patent application ​been filed)   

siTATE: Ilhan H et al., Eur J Nucl Med Mol Imaging. 2019 Sep 6.  ​

GMP Production of

[F-18]siPSMA and [F-18]siTATE:

​• very fast production (<15min)

• at room temperature, thus without volatile 18F-activity

• high yields

• small and simple module

• small and simple cassette and reagent kit

• unparalleled cost efficiency

** results from >400 clinical GMP production (starting activities from 30-100GBq)

*   using 100 GBq [18F]fluoride and 150 nmol precursor (typical value)

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References:    

Wurzer A et al. J Nucl Med. 2019 (accepted) 

​​​siGRP Module

​​​For production of the ​[​F-18]siPSMA and [F-18]SiFAlin-TATE and new upcoming SiFA-Tracers we have designed a dedicated GRP Module that provide considerable advantages:

Production of [F-18]SiFA-based radiopharmaceuticals ​

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References:    

Wurzer A et al. ​ (manuscript in preparation)