The first whole body in-vivo analysis has shown a new radiotracer that can improve medical understanding of inflammation is safe and tolerable in healthy humans.
The new Positron Emission Tomography (PET) radiotracer LW223 targets the 18 kDa translocator protein (TSPO), which is significantly involved in inflammation and is prevalent in diseases such as brain disorders, heart disease, and cancer.
LW223 is the first fluorinated PET radiotracer with binding to human TSPO to be unaffected by the rs6971 polymorphism – a genetic mutation in humans which has thus far hindered TSPO PET inflammation imaging protocols in around 60% of the population – making it a promising clinical tool.
In new research published in the European Journal of Nuclear Medicine and Molecular Imaging, healthy volunteers were given an injection of LW223 PET, and their bodies were scanned for four hours.
The results showed that LW223 PET mainly leaves the body through the liver and intestines and does not significantly break down undesirably inside the body. The amount of radiation associated with this radiotracer is within safety limits, and the minimal radiation dosage compares well to other similar radiotracers in clinical use.
The findings support continued testing of LW223 PET in clinical trials, as it shows potential for safely tracking inflammation and other biological processes in human diseases.
It also contains fluoride as the radioactive element, which, with a physical half-life of about two hours, can be transported between clinical sites, making it immediately clinically and commercially viable in a way that other radioactive tracer isotope, such as Carbon-11, are not.
The research team is led by Professor Adriana Tavares at the University of Edinburgh’s Institute for Neuroscience and Cardiovascular Research, working with Professor Andrew Sutherland of the University of Glasgow and industry partners Life Molecular Imaging (LMI) and XingImaging, supported by Edinburgh Innovations, the University’s commercialisation service, and by the University of Glasgow’s Research and Innovation Services.
Professor Tavares said:
These first-in-human whole-body results mean we can now progress into applying the radiotracer in funded clinical trials in a variety of clinical applications, from myocardial infarction to multiple sclerosis. ”
Professor Sutherland said:
This is the first fluorinated PET tracer in 40 years that seems to be able to bind to the TSPO in humans regardless of the rs6971 polymorphism, and this represents a major development in the field of medicinal chemistry. ”
Dr Gilles Tamagnan, CEO of XingImaging, said:
Through this partnership, XingImaging is exploring the value of LW223 PET as a marker of neuroinflammation in Parkinson’s and Alzheimer’s disease, and we are optimistic about more encouraging results to come. ”
The paper First human whole-body biodistribution and dosimetry analysis of [18F]LW223, a novel TSPO PET radiotracer, is published in the European Journal of Nuclear Medicine and Molecular Imaging.
