FDA Approves Tauvid® To Help Diagnose Alzheimer’s Disease
On May 28, 2020, the FDA approved Tauvid (flortaucipir F18) to image “tau pathology.” Tau pathology is a characteristic of Alzheimer’s disease in the brain. Tauvid is the first drug used to image tau pathology for adults being evaluated for Alzheimer’s disease.1
Tauvid is a radioactive drug given by intravenous injection. It binds to areas in the brain with tau pathology. Brain scanning can then identify the presence of tau pathology.
The drug is a big advance for our ability to diagnose Alzheimer’s disease. This can help people better plan for the future and make informed choices about their health.2
What is tau pathology?
We have an important protein called “tau” in our neurons. Normally, healthy tau proteins stabilize structures that form the skeletons of neurons. Without a stable skeleton, neurons cannot communicate properly. Imagine our network of highways, which needs to be maintained to allow us to transport goods and people across the country.3
But sometimes, tau proteins may become unable to perform their maintenance job. When this happens, tau proteins accumulate and form neurofibrillary tangles (NFTs). The tangled form of tau prevents healthy tau from working. This leaves the cell skeleton unstable and blocks neuron communication, causing dementia.3
How tau pathology happens is complicated and not completely understood. But scientists are studying and testing many therapies for Alzheimer’s disease that prevent tangle formation.4
How does Tauvid work?
Tauvid contains flortaucipir F18, which is a chemical that binds specifically to tau tangles. It is also a radioactive drug. This means that it contains an unstable atom that releases a particle to become stable. Brain scans then detect these particles to identify the location and amount of tau tangles.5
A positive scan would show Tauvid signals in specific regions of the brain. This would support the presence of widespread tau pathology and contribute to an Alzheimer’s disease diagnosis.5
Tau pathology imaging gives doctors information to help manage people’s health. And it can help families make more informed plans and choices about people’s well-being.2
How was Tauvid studied?
Two clinical trials evaluated the success of Tauvid imaging. The first study enrolled 156 terminally ill people who agreed to Tauvid imaging and post-mortem brain donation. Five doctors read the Tauvid scans of 64 of these people. The study compared their readings to the analysis of the post-mortem brains. Doctors reading Tauvid images had high chances of correctly identifying people with tau pathology. They had average-to-high chances of identifying people without tau pathology.1,5
The second study included the same people and an additional 159 people with cognitive impairment being evaluated for Alzheimer’s disease. Five different doctors interpreted their Tauvid scans. The study showed good agreement between doctors’ assessments.1,5
These studies analyzed Tauvid in people with more severe dementia. It may be less effective in people at earlier stages of cognitive decline.1
What else should I know about Tauvid?
The most common side effects of Tauvid are headache, injection site pain, and increased blood pressure. These were the only side effects reported in more than 10 of the 1921 participants in clinical trials.5
Because it is a radioactive drug, Tauvid may cause cancer. But as long as Tauvid is stored and handled properly, the benefits usually outweigh the risks. Radioactive drugs may cause birth defects or negative effects on breastfed infants. Pregnant or lactating women should discuss these risks with their doctor. Tauvid is not able to diagnose chronic traumatic encephalopathy (CTE). People with CTE show different forms of tau pathology than people with Alzheimer’s disease.5
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