What is Vizamyl - Flutemetamolo and what is it used for?
Vizamyl is a radiopharmaceutical (a medicine containing small amounts of a radioactive substance) containing the active ingredient flutemetamol (18F), intended for diagnostic use only. Vizamyl is used in the brain spectroscopic technique in patients with memory disorders, to allow doctors to detect the presence or not of significant amounts of β-amyloid plaques in the brain. Β-amyloid plaques are deposits sometimes present in the brains of people with memory problems caused by dementia (such as Alzheimer's disease, dementia with Lewy bodies and Parkinson's disease) as well as in the brains of some elderly without symptoms of dementia. The spectroscopic technique used with Vizamyl is called positron emission tomography (PET).
How is Vizamyl - Flutemetamol used?
Vizamyl can only be obtained with a prescription and PET scans with Vizamyl should only be requested by physicians experienced in the clinical management of patients with diseases such as Alzheimer's disease and other dementias. Vizamyl is available as a solution for intravenous injection approximately 90 minutes before acquiring a PET image. The acquired image is examined by medical experts in nuclear medicine, specially trained to interpret PET scans with Vizamyl. Patients should discuss the results of the PET exam with their doctor.
How does Vizamyl - Flutemetamolo work?
The active ingredient in Vizamyl, flutemetamol (18F), is a radiopharmaceutical that emits low amounts of radiation and works by binding to βŸ-amyloid plaques in the brain. The radiation emitted can be detected at the PET scan, allowing doctors to know if a significant number of plaques is present or not. If the PET scan shows few plaques or no β-amyloid plaque (negative scan), it is unlikely that the patient is affected by Alzheimer's disease. However, a positive scan by itself is not sufficient to establish a diagnosis in patients with memory disorders, since the presence of plaques is observed in patients with different neurodegenerative dementias as well as in symptom-free elderly. Doctors will then have to interpret the scans in the light of a clinical evaluation.
What benefit has Vizamyl - Flutemetamolo shown during the studies?
Vizamyl was examined in a main study involving 176 patients at a very advanced age, who had allowed autopsy after death to definitively determine the presence or not of significant amounts of β-amyloid plaques cerebral. The study analyzed the sensitivity of PET scans (ie the precision of such scans in identifying patients with a significant amount of plaques in the brain) examined by experts. At the end of the study, 68 autopsies were conducted to definitively detect the presence or absence of significant quantities of β-amyloid plaques in the brain. Comparing the results of autopsies with PET scans showed a sensitivity of scans ranging between 81% and 93%. This means that PET scans have correctly identified 81-93% of patients with significant amounts of plaques in the brain as positive. In a subsequent review, the data of the original 68 patients were analyzed together with the results obtained from subjects who died after the conclusion of the original study, bringing to 106 the total number of patients evaluated. In this new examination, most experts interpreted scans with a sensitivity of around 91% (ie 91% of patients with plaques were identified) and a specificity of 90% (the absence of plaques was correctly detected in 90% of patients without plaques)
What is the risk associated with Vizamyl - Flutemetamolo?
The most common side effects of Vizamyl (which may affect 1-10 patients in 100) are hot flushes, nausea, chest discomfort and increased blood pressure. For the full list of all side effects and restrictions with Vizamyl, see the package leaflet. Vizamyl releases a very low amount of radiation, with a very low risk of cancer or hereditary abnormalities.
Why has Vizamyl - Flutemetamol been approved?
The Agency's Committee for Medicinal Products for Human Use (CHMP) decided that Vizamyl's benefits are greater than its risks and recommended that it be approved for use in the EU. The committee noted that the PET scans acquired with Vizamyl detected the presence of a significant number of β-amyloid plaques in the brain with a high sensitivity and specificity, and that the scans provided information similar to those obtained at autopsy. This is considered a significant improvement in diagnostic performance in patients with memory disorders that are evaluated for Alzheimer's disease and other types of dementia. However, there remains a risk of false positive results (in the case of patients without plaques that are evaluated as positive) and, consequently, scans with Vizamyl should not be used as the sole diagnostic method for dementia, but used in conjunction with the clinical evaluation of the patient. Regarding safety, Vizamyl involves exposing the patient to small amounts of radiation, which fall within the range of other authorized radiopharmaceuticals, for which the safety profile is acceptable. However, the CHMP noted that due to the limited effects of currently available treatments for Alzheimer's disease, there is no solid evidence that acquiring PET scans with Vizamyl allows for an immediate improvement in patient management or benefits for the patient. Furthermore, the usefulness of Vizamyl in predicting the development of Alzheimer's disease in patients with memory disorders or in monitoring patients' response to therapy has not been demonstrated.
What measures are being taken to ensure the safe and effective use of Vizamyl - Flutemetamolo?
A risk management plan has been developed to ensure that Vizamyl is used as safely as possible. Based on this plan, safety information has been included in the summary of product characteristics and the package leaflet for Vizamyl, including the appropriate precautions to be followed by healthcare professionals and patients. In addition, the company that markets Vizamyl will provide access to a training course for all nuclear medicine specialists who could use the medicine in the European Union to ensure accurate and reliable reading of PET scans. Further information is available in the summary of the risk management plan.
More information about Vizamyl - Flutemetamol
On 22 August 2014, the European Commission issued a marketing authorization for Vizamyl, valid throughout the European Union. For more information about Vizamyl therapy, read the package leaflet (also part of the EPAR) or contact your doctor or pharmacist. Last update of this summary: 08-2014.
