VisiMonitor™ ¹⁸F-FAraG PET Tracer

Molecular imaging technology has permitted an increasing development of the overall diagnostic accuracy of cancer in the last years. Design of individually suited therapies, accurate tumor staging, response evaluation, early detection of recurrence and distant lesions have also evolved accompanied by the development of novel molecular imaging technologies. To assess immunotherapy response early in the treatment cycle, Creative Biolabs launches the VisiMonitor™ ¹⁸F-FAraG PET tracer to provide a clinic treatment with an imaging tool for immune-modulating therapy.

Introduction of ¹⁸F-FAraG PET Tracer

• Positron emission tomography (PET)

PET has three key advantages including quantitative capability, high sensitivity, and limitless depth of penetration. In the last years, few PET tracers have been employed for imaging the immune system, and even less for specific imaging of distinct immune cell types such as activated T cells.

• ¹⁸F-FaraG

¹⁸F-FaraG is an analog of arabinosyl guanine (AraG) and a compound that is identified to have specific cytotoxicity towards T-lymphocytes and T-lymphoblastoid cells.

• ¹⁸F-FAraG PET tracer

¹⁸F-FAraG PET tracer is a novel imaging tool to visualize immune response. ¹⁸F-FAraG PET imaging of a murine aGVHD model enabled visualization of secondary lymphoid organs harboring activated donor T cells before clinical symptoms. In addition, tracer biodistribution in healthy humans has shown favorable kinetics (shown as Fig.1).

Fig.1 Whole body PET images of ¹⁸F-FAraG in a healthy human volunteer. (Ronald, 2017)

Mechanism of ¹⁸F-FAraG PET Tracer

Molecular imaging using novel tracers for PET can achieve the in situ detection of T-cells in living organisms. After transporting inside the cell by nucleoside transporters, ¹⁸F-FAraG is phosphorylated by cytoplasmic deoxycytidine and mitochondrial deoxyguanosine kinases, trapping PET probe in the cell. ¹⁸F-FAraG has exhibited high specificity for activated T-cells in vitro and in models of graft-versus-host disease, inflammatory arthritis and cancer. Moreover, ¹⁸F-FAraG imaging may provide a novel method for imaging of activated T cell dynamics in living subjects without toxicity since the tracer is given in very low (ng-μg) mass levels.

Applications of PET ¹⁸F-FAraG PET Tracer

• ¹⁸F-FAraG PET can be used to non-invasively image T-cell infiltration, and detect response to immunomodulatory therapy.
• ¹⁸F-FAraG PET can be employed for CD8 profiling of the tumors and evaluation of chemotherapy-based immune induction strategies.
• ¹⁸F-FAraG PET allows clinicians to utilize existing or novel interventions in a timely fashion and to monitor the outcome of such treatments effectively.
• ¹⁸F-FAraG PET assess the immune-related adverse effects. A whole body on-treatment ¹⁸F-FAraG PET scan may reveal accumulation of cytotoxic T cells in off-target tissues, such as the thyroid, heart, brain or lung, and allow timely intervention and potential prevention of severe adverse events.
• ¹⁸F-FAraG PET is agnostic to the therapy type and can be used for a wide range of T cell modulating therapies including checkpoint inhibitors, cancer vaccines, chemo- and radiation therapy, or a combination of immunotherapy and conventional medicines.

For more details about our VisiMonitor™ ¹⁸F-FAraG PET tracer, please do not hesitate to contact us.

References

1. Guglielmetti, C.; et al. Longitudinal imaging of T-cells and inflammatory demyelination in a preclinical model of multiple sclerosis using ¹⁸F-FAraG PET and MRI. J Nucl Med. 2021, 9: 120.259325.
2. Ronald, J.A.; et al. A PET imaging strategy to visualize activated T cells in acute graft-versus-host disease elicited by allogenic hematopoietic cell transplant. Cancer Res. 2017, 77(11): 2893-2902.
3. Levi, J.; et al. ¹⁸F-AraG PET for CD8 profiling of tumors and assessment of immunomodulation by chemotherapy. J Nucl Med. 2021, 62(6): 802-807.

For Research Use Only | Not For Clinical Use