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Biotech / Medical : Neuroscience -- Ignore unavailable to you. Want to Upgrade?


To: scott_jiminez who wrote (10)7/16/2000 10:10:46 PM
From: el paradisio  Respond to of 278
 
Scott,"far from being immune to hype"...I think,we should not neglect immune research ,because the first promising drug for AD may come from ELAN Corp. ,a vaccine AN-1792:

Scientists Announce Initial Results of Alzheimer Vaccine Treatment in Humans Research Confirms Vaccine's Mechanism of Action
WASHINGTON, D.C., Jul 11, 2000 /PRNewswire via COMTEX/ -- Initial results of an ongoing phase I clinical trial of a potential vaccine for Alzheimer's disease have shown that the vaccine is well tolerated in humans, according to scientists at Elan Pharmaceuticals, a division of Elan Corporation, plc.

The scientists reported their study results today at World Alzheimer Congress 2000.

In their animal research, Elan scientists identified how the compound works to clear plaques out of the brain. In the year since Elan scientists published their findings on the vaccine in transgenic mice -- mice genetically altered to develop Alzheimer's disease -- they have conducted additional safety trials on the compound AN-1792 in other animals, and are now conducting multi-dose phase I clinical trials in humans in coordination with their partner, American Home Products.

"We are extremely pleased with the progress of our phase I trials which have shown that AN-1792 is well tolerated by the patients," says Dale Schenk, Ph.D., Vice President of Discovery Research at Elan Pharmaceuticals. "During the course of our research, we also developed a greater understanding of how the vaccine works to clear amyloid plaques out of the brain and prevent additional plaques from forming."

Basic Science Findings

AN-1792 is a synthetic form of the naturally occurring beta amyloid protein, which has long been identified as the primary component of amyloid plaques. Scientists have hypothesized that amyloid plaques impede nerve cell function and cause nerve cell death in the brains of people with Alzheimer's disease. Although amyloid plaques are found in the brains of most individuals with Alzheimer's, it is not yet known whether plaques are a cause or a result of the disease process.

While conducting additional animal studies of AN-1792, scientists confirmed that the compound leads to an immune response that increases the clearance of beta amyloid plaques from the brain. During the immune response, anti-beta amyloid antibodies are formed that bind to the amyloid plaques. Simultaneously, certain cells that are a part of the immune system in the brain, microglial cells, are activated and begin engulfing the amyloid plaques.

"Amyloid plaques act as a brain invader," added Schenk. "We are optimistic that we can attack this invader at its source and eventually help the millions of people and families worldwide who are living with this devastating disease."

Clinical Findings

In total, about 100 patients in the United States and the United Kingdom will be involved in the phase I clinical trials of AN-1792. Patients in the U.S. received a single dose of the vaccine through injection and, according to the researchers, no obvious safety concerns have been identified. Phase I multiple dose trials currently are underway in the United Kingdom.

"Just a few years ago, talk of a potential vaccine for Alzheimer's disease would have been viewed with much skepticism and disbelief," says Bill Thies, Ph.D., Alzheimer's Association vice president of medical and scientific affairs. "Announcements like this that are grounded in solid scientific research give us tremendous hope. We now are testing the amyloid hypothesis with this vaccine and traditional drug therapy, and we are moving closer to identifying an intervention that will be able to alter the course of the disease."

Memantine is also promising approach,because of modulation of NMDA receptor.
As you remember,we have a reversible cholinesterase inhibitor,Aricept,produced by Pfizer....enchancing neuronal pathways of degenerating neurons...and increasing the concentration of acetylcholine.
The next direction of research,how to stop degeneration of the neurons,should go in the direction of :
1.Immuno...we may have an increase antibodies production against ACh neurons in the aging brain
2.Genes modulation
3.Cell replacement therapy
4.Enchancing cholinergic function,by modulating the receptor,
inhibition of cholinesterase,increase production of ACh.


BTW,I am interested in your opinion on Ritalin.
My personal,unpublished studies proved,that Ritalin is not a specific modulator of Dopamine,Adrenaline or Serotonin.
I my belive,Ritalin is acting only on the capillaries in the brain .High dosages can cause the stroke.
Regards,el



To: scott_jiminez who wrote (10)7/20/2000 2:19:40 PM
From: Biomaven  Read Replies (1) | Respond to of 278
 
scott,

I've certainly never claimed that memantine is a groundbreaking advance. Likely all we can expect from it is that it substantially slows decline in AD, and we don't yet know the longevity of any gains.

However, it seems to me that memantine is showing good enough results to make it an approvable drug:

Efficacy endpoints included the Clinician's Interview-Based Impression of Change (NYU CIBIC-plus), Activities of Daily Living (modified ADCS-ADL Inventory), and cognitive performance (Severe Impairment Battery, SIB). For CIBIC-plus, a mean difference of 0.36 points (p = 0.025; N = 181) was found. For the ADL total score, the mean difference between treatment groups was 3.37 points (p = 0.003; N = 181). This was consistent with Memantine's effect on cognitive performance: for SIB total scores, a 5.70-point mean difference (p = 0.002; N = 179) was shown.

Can any of the claimed AD advances involving other neurotransmitter systems that you mention show comparable or better data? Not that I'm aware of.

Do you consider Aricept to be a groundbreaking drug? I'd say it was an advance, but certainly not a dramatic advance. It currently has annualized sales of some $800 million.

Basically I'm looking at the memantine results from an investment perspective. If their AIDS dementia study show similar results to the AD studies, then I believe NTII will do well. (And of course they will do even better if diabetic neuropathy results hold up).

Peter