Positron emission tomography (PET) is a functional imaging technique that uses radioactive substances known as radiotracers to visualize and measure changes in metabolic processes, and in other physiological activities including blood flow, regional chemical composition, and absorption. Different tracers are used for various imaging purposes, depending on the target process within the body.
Cerebral amyloid angiopathy (CAA) is a form of angiopathy in which amyloid beta peptide deposits in the walls of small to medium blood vessels of the central nervous system and meninges. The term congophilic is sometimes used because the presence of the abnormal aggregations of amyloid can be demonstrated by microscopic examination of brain tissue after staining with Congo red. The amyloid material is only found in the brain and as such the disease is not related to other forms of amyloidosis.
Pittsburgh compound B (PiB) is a radioactive analog of thioflavin T, which can be used in positron emission tomography scans to image beta-amyloid plaques in neuronal tissue. Due to this property, Pittsburgh compound B may be used in investigational studies of Alzheimer's disease.
[18F]Fluorodeoxyglucose (INN), or fluorodeoxyglucose F 18, also commonly called fluorodeoxyglucose and abbreviated [18F]FDG, 2-[18F]FDG or FDG, is a radiopharmaceutical, specifically a radiotracer, used in the medical imaging modality positron emission tomography (PET). Chemically, it is 2-deoxy-2-[18F]fluoro-D-glucose, a glucose analog, with the positron-emitting radionuclide fluorine-18 substituted for the normal hydroxyl group at the C-2 position in the glucose molecule.
Bapineuzumab is a humanized monoclonal antibody that acts on the nervous system and may have potential therapeutic value for the treatment of Alzheimer's disease and possibly glaucoma. However, in 2012 it failed to produce significant cognitive improvements in patients in two major trials, despite lowering key biomarkers of AD, amyloid brain plaque and hyperphosphorylated tau protein in CSF.
Gadobutrol (INN) (Gd-DO3A-butrol) is a gadolinium-based MRI contrast agent (GBCA).
Solanezumab is a monoclonal antibody being investigated by Eli Lilly as a neuroprotector for patients with Alzheimer's disease. The drug originally attracted extensive media coverage proclaiming it a breakthrough, but it has failed to show promise in Phase III trials.
Avid Radiopharmaceuticals is an American company, founded by Dr. Daniel Skovronsky, and based at the University City Science Center research campus in Philadelphia, Pennsylvania. The company has developed a radioactive tracer called florbetapir (18F). Florbetapir can be used to detect beta amyloid plaques in patients with memory problems using positron emission tomography (PET) scans, making the company the first to bring to market an FDA-approved method that can directly detect this hallmark pathology of Alzheimer's disease.
Brain positron emission tomography is a form of positron emission tomography (PET) that is used to measure brain metabolism and the distribution of exogenous radiolabeled chemical agents throughout the brain. PET measures emissions from radioactively labeled metabolically active chemicals that have been injected into the bloodstream. The emission data from brain PET are computer-processed to produce multi-dimensional images of the distribution of the chemicals throughout the brain.
Crenezumab is a fully humanized monoclonal antibody against human 1-40 and 1-42 beta amyloid, which is being investigated as a treatment of Alzheimer's disease. Crenezumab is highly homologous to solanezumab, another monoclonal antibody targeting amyloid-β peptides. In June 2022, the US National Institutes of Health announced that the drug failed as a medication for early-onset Alzheimer's disease following the results of a decade-long clinical trial.
Florbetapir (18F), sold under the brand name Amyvid, is a PET scanning radiopharmaceutical compound containing the radionuclide fluorine-18 that was approved for use in the United States in 2012, as a diagnostic tool for Alzheimer's disease. Florbetapir, like Pittsburgh compound B (PiB), binds to beta-amyloid, however fluorine-18 has a half-life of 109.75 minutes, in contrast to PiB's radioactive half life of 20 minutes. The longer life allows the tracer to accumulate significantly more in the brains of people with AD, particularly in the regions known to be associated with beta-amyloid deposits.
Aducanumab, sold under the brand name Aduhelm, is a medication designed to treat Alzheimer's disease (AD). It is a monoclonal antibody that targets aggregated forms (plaque) of amyloid beta (Aβ) found in the brains of people with Alzheimer's disease to reduce its buildup. It was developed by Biogen and Eisai. Aducanumab is given via intravenous infusion.
Florbetaben, sold under the brand name Neuraceq, is a diagnostic radiotracer developed for routine clinical application to visualize β-amyloid plaques in the brain. It is a fluorine-18 (18F)-labeled stilbene derivative.
Lecanemab, sold under the brand name Leqembi, is a monoclonal antibody medication used for the treatment of Alzheimer's disease. Lecanemab is an amyloid beta-directed antibody. It is given via intravenous infusion. The most common side effects of lecanemab include headache, infusion-related reactions, and amyloid-related imaging abnormalities, a side effect known to occur with the class of antibodies targeting amyloid.
Flortaucipir (18F), sold under the brand name Tauvid, is a radioactive diagnostic agent indicated for use with positron emission tomography (PET) imaging to image the brain.
Julie C. Price is an American medical physicist and professor of radiology at Massachusetts General Hospital (MGH), Harvard Medical School (HMS), as well as the director of PET Pharmacokinetic Modeling at the Athinoula A. Martinos Center at MGH. Price is a leader in the study and application of quantitative positron emission tomography (PET) methods. Prior to this, Price worked with Pittsburgh colleagues to lead the first fully quantitative pharmacokinetic evaluations of 11C-labeled Pittsburgh compound-B (PIB), one of the most widely used PET ligands for imaging amyloid beta plaques. As a principal investigator at MGH, Price continues work to validate novel PET methods for imaging biological markers of health and disease in studies of aging and neurodegeneration, including studies of glucose metabolism, protein expression, neurotransmitter system function, and tau and amyloid beta plaque burden.
Donanemab is a biological drug in Phase III clinical trials to determine whether it slows the progression of early Alzheimer's disease. Donanemab has shown positive results in its first trials. Donanemab was developed by the Eli Lilly and Co. and is under clinical development as a possible treatment for Alzheimer's disease. There is currently no approved cure or disease-modifying treatment for Alzheimer's disease except for lecanemab.
Piflufolastat F-18, sold under the brand name Pylarify among others, is a radioactive diagnostic agent used for positron emission tomography (PET) imaging. It is given by intravenous injection.
Hartmuth Christian Kolb is a German chemist. He is considered one of the founders of click chemistry.
Anti-amyloid drugs, also known as anti-amyloid antibodies (AAA), are a class of monoclonal antibodies developed to treat Alzheimer's disease. The first drug in the class to be developed, in the early 2000s, was bapineuzumab, but it did not show effectiveness in later-stage trials. The first drug to be FDA approved was aducanumab in 2021.
