Flutemetamol (¹⁸F) (trade name Vizamyl, by

GE Healthcare GE HealthCare is a subsidiary of American multinational conglomerate General Electric incorporated in New York and headquartered in Chicago, Illinois. As of 2017, it is a manufacturer and distributor of diagnostic imaging agents and radiopharma ...

) is a

PET scan 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, ...

ning

radiopharmaceutical Radiopharmaceuticals, or medicinal radiocompounds, are a group of pharmaceutical drugs containing radioactive isotopes. Radiopharmaceuticals can be used as diagnostic and therapeutic agents. Radiopharmaceuticals emit radiation themselves, which ...

containing the radionuclide

fluorine-18 Fluorine-18 (18F) is a fluorine radioisotope which is an important source of positrons. It has a mass of 18.0009380(6) u and its half-life is 109.771(20) minutes. It decays by positron emission 96% of the time and electron capture 4% of the time ...

, used as a diagnostic tool for Alzheimer's disease.

Adverse effects

Adverse effects of flutemetamol include headache,

nausea Nausea is a diffuse sensation of unease and discomfort, sometimes perceived as an urge to vomit. While not painful, it can be a debilitating symptom if prolonged and has been described as placing discomfort on the chest, abdomen, or back of the ...

, dizziness, flushing and increased blood pressure.

Mechanism of action

After the substance is given intravenously, it accumulates in

beta amyloid Beta (, ; uppercase , lowercase , or cursive ; grc, βῆτα, bē̂ta or ell, βήτα, víta) is the second letter of the Greek alphabet. In the system of Greek numerals, it has a value of 2. In Modern Greek, it represents the voiced labiod ...

plaques in the patient's brain, which thus become visible via positron emission tomography (PET).

Manufacturing and distribution

Flutemetamol (¹⁸F) can be produced within five to six hours. It then undergoes a quality check and is ready to be distributed immediately after. The product must be used within a certain time frame for maximum efficacy. Because of the limited time window, flutemetamol is not produced until an order has been placed. Flutemetamol is typically administered intravenously in 1 to 10 mL doses. Average costs for PET scans without insurance coverage are around $3,000. Currently Medicare does not cover use of amyloid imaging agents except for in clinical trials. Because of this, there is a low market for flutemetamol.

History

Flutemetamol was first approved for use in the US by the

Food and Drug Administration The United States Food and Drug Administration (FDA or US FDA) is a List of United States federal agencies, federal agency of the United States Department of Health and Human Services, Department of Health and Human Services. The FDA is respon ...

(FDA) in 2013 for intravenous use.

Clinical trials

Two clinical trials were conducted for flutemetamol (¹⁸F). The first compared PET scans of terminally ill patients with flutemetamol to

post mortem An autopsy (post-mortem examination, obduction, necropsy, or autopsia cadaverum) is a surgical procedure that consists of a thorough Physical examination, examination of a Cadaver, corpse by dissection to determine the cause, mode, and manner o ...

standard-of-truth assessments of cerebral cortical neuritic plaque density. The second trial assessed intra-reader reproducibility of PET scans using flutemetamol.

Clinical trial 1

Of the 176 patients imaged in this trial had a median age was 82, with 57 of patients being female. The initial flutemetamol PET scan resulted in 43 positive and 25 negative results for cerebral cortisol amyloid status. 69 of the initial patients died within 13 months of the flutemetamol PET scan. The autopsy for 67 of those patients determined the global brain neuritic plaque density category. Of those 67 patients 41 were positive and 26 were negative. These results correlate with the pre-mortem scan.

Clinical trial 2

The second clinical trial included 276 subjects with a median age of 72. The trial measured the effectiveness of an electronic training program for flutemetamol image interpretation using PET scans from trial 1 among other subjects with a variety of cognitive impairment. Final results met the pre-specified success rate with a

Fleiss' kappa statistic Fleiss' kappa (named after Joseph L. Fleiss) is a statistical measure for assessing the reliability of agreement between a fixed number of raters when assigning categorical ratings to a number of items or classifying items. This contrasts with ...

of 0.83.

Society and culture

Economics

GE Healthcare's largest marketing aspect for flutemetamol is that it is the only FDA approved amyloid imaging agent for colour image interpretation.

References

{{Diagnostic radiopharmaceuticals Alzheimer's disease Radiopharmaceuticals Organofluorides