ALS drug repurposed for PET imaging

Experts from St. Jude Children’s Research Hospital have successfully repurposed a common drug so that it can be used in PET imaging of the brain. 

Edaravone, commonly sold under the brand name Radicava, is an antioxidant medication used to treat amyotrophic lateral sclerosis (ALS) and occasionally stroke. However, experts recently discovered the drug can also be used to examine the central nervous system on PET imaging, which could improve the diagnosis of numerous neurodegenerative diseases. 

Researchers radiolabeled the drug so that they could follow its movement and breakdown in the body to help visualize oxidative stress on the brain. Oxidative stress has been implicated in many neurodegenerative diseases. Caused by an accumulation of reactive oxygen and nitrogen species (RONS), oxidative stress inhibits the body’s ability to eliminate toxins, resulting in cell damage and eventually causing neurodegeneration.

The team believes that by assessing imaging for signs of oxidative stress, it may be possible to diagnose conditions like Alzheimer’s prior to the onset of cognitive decline.  

Since edaravone is an antioxidant, it naturally interacts with RONS. When radiolabeled and administered to patients, it releases positrons that can be visualized on PET scans. On imaging, the tracer lights up in areas where RONS have built up, thus giving providers insight into areas that might have undergone cellular damage. 

“The goal in imaging is to promote contrast, so we want something that engages with its target rapidly but then also rapidly clears so you can see your target right away,” explained corresponding author Kiel Neumann, PhD, with the St. Jude Department of Radiology. “What was unique about this drug is that when it reacts with oxidative stress, it undergoes a massive structural and polarity change which keeps it in the cell and promotes contrast.”  

In addition to its excellent bonding ability, the drug can also be utilized during PET exams for treatment, improving both the detection and treatment of neurodegenerative conditions, the group suggested. 

“Ultimately, our goal is to use this to impact clinical care.” Neumann said. “Therapeutic intervention using this technology for clinical disease management is the future.” 

Learn more about the research here.