Progressive Supranuclear Palsy (PSP), Corticobasal Syndrome (CBS), and behavioral variant Frontotemporal Dementia (bvFTD) are devastating brain diseases caused by abnormal buildup of a protein called 4R tau. Currently, there is no approved imaging tool to track disease progression in these conditions—making it difficult to test new treatments in clinical trials.

[¹⁸F]PI-2620 is an advanced brain imaging tracer designed to detect tau buildup using positron emission tomography (PET), a technique that allows scientists to visualize changes in the brain in living individuals. Early studies suggest it can identify areas affected by 4R tau, especially in PSP and CBS. However, we don’t yet know whether this tracer can reliably track changes in tau over time.

This study is led by Dr. Alexis Moscoso of ZRO Imaging as Principal Investigator and conducted at the Complejo Hospitalario Universitario de Santiago de Compostela (CHUS) under the clinical leadership of Dra. Virginia Pubul Núñez, with funding support from Biogen. The study will follow individuals with PSP, CBS, bvFTD, and healthy controls over 12 months. Participants will undergo PET scans with [¹⁸F]PI-2620 at three timepoints to see if tracer uptake increases in areas known to be affected by disease. We will also assess whether changes in PET signal relate to worsening symptoms.

To strengthen the study’s design, we are seeking $599,992 in co-funding from the Alzheimer’s Drug Discovery Foundation (ADDF). This will support three critical enhancements:

1.     Adding a CBS patient group to broaden disease coverage;

2.     Performing amyloid PET scans to rule out overlapping Alzheimer’s disease; and

3.     Including MRI scans to track brain shrinkage alongside PET changes.

By validating [¹⁸F]PI-2620 as a biomarker of disease progression, this study will help accelerate treatment development for 4R tauopathies. It will also provide important insights into how tau pathology, brain structure, and symptoms evolve together—laying the groundwork for smarter, more targeted clinical trials.