Amyvid, Alzheimer's Brain Plaque Imaging Test, OKed By FDA

WASHINGTON, April 7 (Reuters) - U.S. regulators gave the nod to an imaging test from Eli Lilly and Co. that can for the first time help doctors detect brain plaque tied to Alzheimer's disease, the company said.

The U.S. Food and Drug Administration approved the radioactive dye, called Amyvid, to help doctors rule out whether patients have Alzheimer's, the most common form of dementia, Lilly announced late on Friday.

The dye binds to clumps of a toxic protein called beta amyloid that accumulates in the brains of patients with Alzheimer's. Doctors can then see the plaque light up on a positron emission tomography, or PET, scan.

Patients with Alzheimer's always have some brain plaque, so its absence in the test would tell doctors to look for other causes of mental decline, such as depression or medications, Lilly has said.

But Lilly, which plans to sell the drug through its unit Avid Radiopharmaceuticals Inc, said the test should not be used to diagnose Alzheimer's, since brain plaque can also be tied to other neurologic conditions and may occur naturally in older people with normal mental states.

An FDA advisory panel recommended against approving the dye last year, saying doctors might have trouble interpreting scans of the plaque, and the FDA rejected Amyvid last March.

Since then, Eli Lilly said it has worked to identify better ways of training doctors to use the test.

Dr. Daniel Skovronsky, CEO of Avid, said one in five patients who are diagnosed with Alzheimer's turn out not to have the disease after an autopsy.

"The approval of Amyvid offers physicians a tool that, in conjunction with other diagnostic evaluations, can provide information to help physicians evaluate their patients," he said in the company's statement from Friday.

There is currently no cure for Alzheimer's, a mind-robbing disease that affects more than 35 million people worldwide and gets worse with age.

But an early hint that something is wrong might improve the success of drugs meant to prevent or delay disease progression, researchers believe.

Avid has been in the lead in the race for imaging agents for Alzheimer's, which are estimated to have a potential global market anywhere from $1 billion to $5 billion.

General Electric Co and Bayer AG are developing rival products.

Lilly, as well as Pfizer Inc, are the farthest along in developing experimental medicines to treat Alzheimer's. Lilly expects to release final data for its contender, solanezumab, as soon as this summer.

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Comments

[Tim Strane]

11:51 AM on 04/10/2012

Point of clarification: Amyvid is not a "dye". The term dye has been broadly and incorrectly applied to iodine containing materials that are used as radiographic contrast materials. These iodine containing materials are not radioactive and have a rather significant rate of adverse reaction in patients, so it is important to determine if a patient has had a prior study with these materials and if a reaction has occured. Amyvid contains a radioactive isotope fluorine 18, that allows it's location in the body to be determined during the imaging study. The rate of adverse reactions with radioactive imaging agents is very very small.

[Joseph Leslie]

01:36 AM on 04/10/2012

They paid for Dick Cheney to get a heart (his first one) so why won't they pay for Alzheimer's testing!

[aribritt]

11:40 PM on 04/09/2012

What's the point in testing for a disease for which there is no cure or treatment allowing the sufferers to lead a high quality life? Insurance companies, rightly, will not pay for the genetic testing to see whether family members have a gene anomaly which predisposes them to the disease because there is no treatment for it. My Mom is suffering from dementia, likely Alzheimer's judging by the progression, and the only reason I'm allowing her medical caregivers keep her on the drugs that supposedly slow the disease is because the theory is that it will keep her performing some activities of daily living, like toileting herself, a little longer. I refuse to be genetically tested for the gene though because while I may be a carrier doesn't mean it's going to manifest in me. My Mom had blonde hair and is blue eyed and I'm a brunette with brown eyes. Clearly I'm a carrier of the blonde blue eyed gene but just as clearly they did not manifest. Common sense would prevail that one should only know genetic predisposition if there is something concrete that can be done to prevent the disease or cure the illness. Healthcare costs would go down if the big drug companies, like Eli Lilly in this case, would stop giving doctors expensive toys to play with and would actually produce drugs and tests that have a real chance of curing a disease or giving disease sufferers back their quality of life.

[jyrkpcnp]

09:20 PM on 04/09/2012

"Senility" was once used as a trash-can term for dementia. Now "Alzheimer's" is the new trash-can term for dementia. Nice that there is now an FDA test to show amyloid plaque in the brain, but so what? There are so many other conditions and forms of dementia that can confuse a test like this. So the test is positive? So what? Then what? It doesn't tell a cause, nor a treatment that makes a particle of difference, except perhaps to retard the dementia for 6-12 months. How much does this scan cost, and will insurance pay for it????? Wish this were a medical miracle, but it's just another expensive test until proven otherwise.

[Writerofzion]

05:48 PM on 04/09/2012

I agree with the doctor's comments. The causes of dementia have to be defined and corrected and this test doesn't do much of that. It will just result in more medications to patients who need investigation. My sister had profound hearing loss and was diagnosed with dementia instead. So sad.

[palmdesertsandra]

05:28 PM on 04/09/2012

This comment isn't about Alzheimers, it's about a Huffington Post video ala AOL. Carissa Loethen has probably galvanized the Society of Plumbers by voicing that "plumbers aren't that smart."
I wholeheartedly disagree, as I would sure like to know how they can fix everything near running water, and I don't agree that marrying a plumber is "marrying down." By the way Carissa it's older than they not "older than them." I sure wish AOL had a comments area for people like me who have to resort to other areas to get their message across. Also to comment on women not marrying older rich men, I think that we have realized (finally) that when you do that you live their life (as many of these May - December brides can attest" not yours - life is just too short to not live it to the fullest.

[Joseph Leslie]

01:39 AM on 04/10/2012

I'm married to a woman who is 26 years younger than me! Don't knock it until you've tried it! We have 2 children that we made with no medical help. She is happy with me and I with her.

[palmdesertsandra]

09:16 PM on 04/10/2012

Mr. Leslie, there are always exceptions to everything. Let's hear from the wifey now.

[DrMaxChartrand]

03:11 PM on 04/09/2012

Loss of astroglia, long-term acidosis, and cortical inflammation in the long-term are causes of dementia---uncorrected hearing impairment in older adults is the item that gets the shortest shrift, however, by the medical field. No diagnosis in mental health is valid in older adults that does not first ascertain and remove hearing loss before concluding diagnosis. I think we can safely say that at about 90% of those placed on AD medication are instead suffering from significant hearing loss that, once addressed, resolves most of the memory issues. See research out of Brandeis and Johns Hopkins, and the University of Pittsburgh.

[jgamble28]

03:05 PM on 04/09/2012

HOw wonderful that there is now a test for Alzhiemers disease. I hope one day there will be a cure for it.

[DrMaxChartrand]

03:15 PM on 04/09/2012

Please, see my remarks below yours--this is not a reliable test for Alz and certainly does not point to a cure. Because the causes (cortical inflammation, hearing loss, unresolved infection, medication, heavy metal accumulations, chronic hypotension, nutritional deficiencies, chronic dehydration, etc.) vary from individual to individual the "cure" will involve a varied subset of factors that need to be assessed individually. We've had this amyloid plaque theory and the tests you are reading about now for a long, long time, and they are have long proven unreliable. Nothing beats getting to the underlying cause.

[jgamble28]

04:30 PM on 04/10/2012

Thanks for your reply DrMaxChartrand. I understand what your saying.

[DrMaxChartrand]

03:05 PM on 04/09/2012

Findings from my doctoral students on this issue:

1. Abnormal accumulations of beta amyloid (the protein in plaques) and tau (the protein in tangles) are not harmful, and are simply end-stage signs of earlier problems

2. Recent research indicates that beta amyloid may be protective – a normal immune response and an anti-oxidant against future damage

3. The accumulation of beta amyloid that can be seen at autopsy (and in new brains scans) is not well correlated with dementia

4. The focus on these abnormal proteins has crowded out funding needed to research other hypotheses & over-promotes questionable medication.

[DrMaxChartrand]

02:58 PM on 04/09/2012

Sorry to see the FDA succumb to using the wrong model for Alzheimer's Disease. The evidence of plaques, which research shows actually protects surviving brain neurons in the face of loss of astroglia cells, does not correlate well with degree of dementia. It merely signals that underlying problems exist--probably reminiscent of those found in neuropathies (i.e., loss of myelin, free radical destruction, etc). The sad truth is that AD is very difficult to diagnose, and more often than not is either a misdiagnosis or over-diagnosis, because hearing loss is usually the main undetected, uncorrected culprit. But who is tesing auditory acuity and separating out such non-dementia components before concluding their diagnosis? Almost no one! Shame on the industry for conveniently overlooking another elephant in the living room, which consigns millions to being mistreated/overtreated with potentially unsafe drugs that make the problem worse. No mental health evaluation of the elderly is valid without first ascertaining and correcting hearing loss.

[croshatch]

12:06 AM on 04/10/2012

" hearing loss is usually the main undetected, uncorrected culprit."

I know you're a doctor (you say you are) and I am not but I have to disagree with this statement. Yes, hearing loss could be an explanation in some cases but "usually"? My mother has dementia and there is absolutely no indication that her condition is due to hearing loss. In fact, she seems to hear perfectly well but is unable to communicate in a meaningful way. Having spent some time in the home my Mother shares with other dementia patients, I see little indication of hearing loss being the root of their problems.

[Emereaux]

02:26 PM on 04/09/2012

At least this is a first step in the right direction. Just because there is a learning curve in diagnosing Alzheimers doesn't mean you shouldn't use it.

[DrMaxChartrand]

03:07 PM on 04/09/2012

The model on Alzheimer's is quite wrong, I'm afraid. Having been involved in research on this for more than 30 years I am dissapointed that this approach is being used as an indicator of the presence of AD...it is instead an indicator of other issues, such as developing neuropathy, acidosis, inflammation, and long-standing unresolved infections. See the findings of my doctoral students above, once HP editors approve it. Thank you.

[-swift]

10:28 AM on 04/09/2012

I have a brain cloud...

[my 1 cent due to economy]

07:32 PM on 04/09/2012

You mean you were diagnosed with something called a brain cloud and didn't ask for a second opinion?! It's always gonna be something with you, isn't it Joe?

[-swift]

07:48 PM on 04/09/2012

We are a tiny but dedicated fan group.