PBR28-PET in Inflammatory Joint disease (ASTRID)
Research type
Research Study
Full title
An imaging study to evaluate the specificity of the translocator protein (TSPO) radioligand, [11C]PBR28 in patients with Inflammatory Joint diseases (ASTRID)
IRAS ID
216737
Contact name
Azeem Saleem
Contact email
Sponsor organisation
Imanova
Duration of Study in the UK
1 years, 6 months, 0 days
Research summary
The Translocator Protein (TSPO) located within the cells such as macrophages reaches high levels of expression in inflammatory conditions. PBR28 is a chemical substance that binds to TSPO (a TSPO ligand). When radioactivity in the form of carbon-11 is tagged to PBR 28 ([11C]PBR28 - called a radioligand) and is administered, its uptake in the inflammatory body regions can be measured using positron emission tomography (PET). We are currently evaluating uptake of PBR28 in the joints of patients with rheumatoid and psoriatic arthritis as an academic collaborative study. Interim results have shown that a higher uptake is observed in the joints of patients with rheumatoid and psoriatic arthritis compared to the joints of healthy volunteers.
However, it is possible that the radioligand that is taken up in the joints of patients gets attached to cells that do not express TSPO (known as non-specific binding) and/or is a reflection of other inflammation associated processes such as increased vascularity. In order to evaluate the specific binding ability of PBR28, we plan to do a TSPO blocking study by administering XBD173 (a TSPO targeting drug) to bind to TSPO and block binding of the PET ligand and measuring the radioligand uptake. Such a blocking study will help us to work out how much of a PET signal represents “specific binding” (of the radioligand to the target of interest), and how much represents “non-specific binding” (of the radioligand to many other structures which are not of interest).
This study will therefore aim to evaluate the specificity of PBR28 binding in the joints of patients with inflammatory joint disease. Up to 12 with Inflammatory Joint disease (IJD) will be evaluated in this study. The study is sponsored by Imanova. Subjects will be recruited at NHS sites and all subjects will have their scans done at Imanova Ltd, London. We expect the study to last up to 18 months.REC name
West Midlands - Black Country Research Ethics Committee
REC reference
17/WM/0082
Date of REC Opinion
20 Mar 2017
REC opinion
Further Information Favourable Opinion