A pair of drugs has been selected for evaluation in a platform trial that aims to accelerate the development of treatments for progressive supranuclear palsy (PSP).

The trial is being conducted by researchers at the University of California, San Francisco; the University of California, San Diego; and Massachusetts General Hospital.

Drugs for Other Tauopathies Might Work for PSP

PSP is one of three movement-based FTD disorders, and, like corticobasal syndrome (CBS), is associated with a decline in motor function similar to Parkinson’s disease. PSP, like CBS and ALS-FTD, is driven by a pathology associated with the tau protein.

Because of this shared protein, drugs that work for other tauopathies like ALS-FTD or Alzheimer’s disease might work for PSP. Researchers at UCSF previously announced they intended to conduct a “platform trial” where multiple existing drugs would be evaluated simultaneously against the same control group. The trial’s design allows multiple drugs to be assessed successively, which lets the studies continue even if some drugs do not work.

Researchers with PSP Platform Trial named two experimental drugs to be evaluated in the first study round: AADvac1, created by Axon Neuroscience, and AZP2006, created by Alzprotect. The drugs have distinct mechanisms of action for managing dysfunctional tau, and both have demonstrated positive results in earlier trials.

AADvac1 is an immunotherapy that targets PSP-associated tau proteins, triggering the production of antibodies that bind to tau and prevent it from spreading. Rather than directly “attacking” tau, AZP2006 helps restore lysosome function and modulate the production of the neuroprotective protein progranulin, which can reduce tau aggregation and neuroinflammation. The two drugs will be evaluated over 12 months, followed by a 12-month open-label extension, where control participants will receive working drugs instead of placebos. Additional medications to be evaluated will be announced later this year.

“This public-private partnership represents an unprecedented opportunity to accelerate the development of treatments for PSP,” said Adam Boxer, MD, PhD, a professor at the UCSF Department of Neurology and principal investigator for the trial (and a member of the AFTD Medical Advisory Council).

“By bringing together innovative therapeutic approaches like AADvac1 and AZP2006 in an efficient clinical trial design, we aim to address the urgent needs of patients and their families in less time, at a lower cost, and with fewer patients on placebo than traditional clinical trials,” Dr. Boxer said.

According to a press release from the participating organizations, enrollment for the trial will begin at the end of 2025. Recruitment will focus on people with PSP Richardson syndrome (PSP-RS), the most common subtype of the disorder. The scientists behind the study have emphasized the goal of enrolling a population of participants that are fully representative of the U.S., with the trial providing language support and covering transportation and accommodation costs. To receive news on enrollment for the PSP Platform Trial, sign up for status updates on CurePSP’s website.

Are you interested in participating in a study like the PSP Platform Trial? Sign up for the FTD Disorders Registry to keep up to date on trials seeking participants and other opportunities to participate in FTD research. If you have questions about this or other clinical trials, contact AFTD’s HelpLine at 1-866-507-7222 or info@theaftd.org.