Leading Alzheimer’s researchers are optimistic that effective treatments to significantly slow or even halt the symptoms of this agonizing and ultimately fatal disease will be available within the next five years.
The hope springs from important breakthroughs on several fronts. Advances in high-powered imaging through PET (positron emission tomography) scans are giving researchers better diagnostic tools with which to view the brain. And a renewed interest in different brain proteins is providing greater clues as to which ones are responsible for kick-starting this devastating disease in the first place.
These discoveries have led to a flurry of clinical trials and studies now under way, and that’s good news for Alzheimer’s patients. Researchers say the work being done today could bring about a host of new drugs to treat the disease better and more effectively than anything currently on the market. These new therapies could potentially stop the progression of the disease before symptoms, like memory loss and confusion, ever start — something that’s not possible with the drugs now being prescribed.
Says Dr. Marc Diamond, founding director of the Center for Alzheimer’s and Neurodegenerative Diseases at the University of Texas Southwestern and one of the leading voices on Alzheimer’s research: “It’s an incredibly exciting time right now.”
A devastating disease
To truly understand just how catastrophic an illness Alzheimer’s is, consider that it is the only cause of death among the top 10 in the U.S. that can’t yet be prevented, cured or even slowed. Someone diagnosed with cancer, heart disease or even HIV/AIDS has a better chance of surviving — and having a better quality of life while battling the disease — than a person diagnosed with Alzheimer’s.
According to the Alzheimer’s Association, there are now 5.3 million Americans age 65 and older living with the disease. The total direct cost to the U.S. economy of caring for those with Alzheimer’s: a staggering $226 billion, with half being borne by Medicare.
Delaying the onset of the disease by just five years, research studies show, could decrease Medicare spending by 50 percent. That’s an important point to consider, because economists forecast that unless something is done to cure or even slow the symptoms, the number of people with Alzheimer’s will rise to 16 million by 2050 and cost the U.S. economy $1.1 trillion. The portion covered by Medicare will balloon to $589 billion.
Closer to home, the financial burden of caring for someone with Alzheimer’s can be devastating. According to a recent study by the Annals of Internal Medicine, the cost of caring for a person with Alzheimer’s in the last five years of life is $287,038.
That’s far higher than the costs incurred for a person who died from cancer or heart disease. The reason: Alzheimer’s patients need the kind of care at the end of their lives — bathing, dressing and eating — that’s not covered by insurance. This puts a tremendous burden on a spouse or, in many cases, adult children who may be trying to save for their own retirement or have college tuitions to pay.
One point that all the experts we spoke with agree on is that federal funding for Alzheimer’s research needs to increase — and soon. Currently, just under $1 billion a year is allocated for Alzheimer’s research. That’s far less than the $5 billion spent on cancer or the $3 billion on HIV/AIDS research, according to the Alzheimer’s Association.
“This is clearly the underfunded and understudied problem of the 21st century,” says Dr. Bruce Miller, director of the Memory and Aging Center at the University of California, San Francisco. “We’ve made a lot of progress in therapies around heart disease, cancer and stroke, and we need to move faster in Alzheimer’s research. If we can’t find better therapies for an aging brain, as a society we will dramatically suffer.”
“The cost of caring for a person with Alzheimer’s in the last five years of life is $287,038.”
A lack of effective drugs
The FDA-approved drugs now on the market and most widely prescribed to treat Alzheimer’s — Aricept and Namenda — are helpful but limited, doctors say. “What’s available now are symptomatic treatments that simply give a patient maybe six to 12 months of doing just a little bit better,” says Dr. Reisa Sperling, a leading Alzheimer’s researcher and professor of neurology at Harvard Medical School. Even the newest drug on the market — Namzaric — is basically a combination of two existing drugs and claims only to slow the worsening of symptoms for a while. Like Aricept and Namenda, Namzaric has no effect on stopping or preventing the underlying disease.
But now it seems like the focus — and promise — of Alzheimer’s research is beginning to shift. For the past two decades the Holy Grail in research has been an influential brain protein called beta-amyloid. Over time this protein can build up outside the brain’s neurons and form what’s known as amyloid plaque. The hypothesis for decades has been that it’s this plaque buildup that ultimately leads to Alzheimer’s in certain patients.
As a result, the overwhelming focus in the field has been on beta-amyloid. “For the past 15 or 20 years, if a researcher was not studying beta-amyloid, the chances of getting funding or grant money was quite low,” says Dr. Jim Sullivan, vice president of discovery for AbbVie, a pharmaceutical company involved in Alzheimer’s research.
The problem with this singular approach is that, in patients with moderate to severe Alzheimer’s symptoms, lowering beta-amyloid levels does not make a difference in the severity of the disease or its progression. Further complicating the picture is the fact that, thanks to the brain images now possible with PET scans, it has been proved that individuals can have significant levels of amyloid in their brain and not show signs of Alzheimer’s or any other type of dementia.
These findings have ignited renewed interest in other cognitive culprits; chief among them is another brain protein, called tau. Unlike beta-amyloid, which forms and builds up outside the neurons in the brain, tau develops inside the neurons. From there it can do its damage by traveling to neighboring cells and acting as a sort of virus that corrupts the normal protein of these other cells. For this reason, researchers believe tau may play an even more direct and influential role than beta-amyloid in the development of Alzheimer’s and other forms of dementia.
Dr. Diamond of the University of Texas describes the relationship between these two proteins this way: “If [beta-amyloid] unlocks the barn door and let’s the tau out, then tau is the horse that goes running off,” he says. “It’s the progression of tau as it moves through your brain that actually causes Alzheimer’s dementia, but it’s the [beta-amyloid] that sets you up to get that pathology.”
Searching for a better treatment
If the past several decades were focused on developing drugs that might improve life for patients with symptoms of Alzheimer’s, current research is all about arresting — or even preventing — the disease before the first symptoms ever appear. Says Dr. Miller of UC San Francisco: “We know now that prevention of this disease is feasible and something our field will conquer.”
In other diseases, such as certain types of cancer or heart disease, genetic screenings are often the first line of defense. However, that approach is hotly debated when it comes to screening for Alzheimer’s. “I don’t think we should be screening for the presence of beta-amyloid in the general population until we have something effective to offer people,” says Dr. Sperling.
In the case of individuals with a family history of Alzheimer’s, the testing may be warranted, Dr. Miller says. But he adds it still leads to an uneasy choice. “There are those individuals who might argue that it’s a person’s right to know if they’re going to get the disease,” he says.
And then there are doctors who argue that giving people this information does not improve the quality of life but in fact worsens it, because there are no effective treatments to stop the disease, he adds.
In the meantime, multiple studies and trials involving both tau and beta-amyloid are now under way to figure out how to prevent Alzheimer’s. On the tau front, pharmaceutical company AbbVie and C2N Diagnostics are in Phase 1 of a clinical trial to test a tau antibody in patients with progressive supranuclear palsy (PSP), a neurological disease closely related to Alzheimer’s. Early next year, the company will start Phase 1 testing of the antibody with Alzheimer’s patients. The goal, says Dr. Sullivan, is to slow down the progression of the disease by blocking the spread and accumulation of tau in the brain.
“Someone in the U.S. develops Alzheimer’s every 67 seconds.”
At Harvard, Dr. Sperling is the project leader for a clinical study that is exploring if lowering beta-amyloid buildup in otherwise healthy patients with no memory loss can prevent Alzheimer’s from developing down the road. The so-called A4 study (Anti-Amyloid Treatment in Asymptomatic Alzheimer’s Disease) is a public/private partnership between the National Institutes of Health (NIH) and pharmaceutical company Eli Lilly and will include approximately 1,000 people ages 65 to 85 over the next three and a half years.
Half the group will receive the drug being tested, and half will get a placebo. Every six months, patients will undergo cognitive testing to see if there is any difference in their memory and recall. At three points during the study, they will have a brain PET scan to see if their amyloid buildup has changed.
“This is analogous to what we do with cholesterol, by trying to do things that keep it in check so that we can prevent heart attacks and strokes before they happen,” Dr. Sperling says.
Whether it’s through the tau protein or beta-amyloid, preventing Alzheimer’s is the major focus of researchers today. “I think our best bet with Alzheimer’s is to act before there are symptoms,” she says. “Because by the time that happens, there’s more than just a head full of amyloid. There’s already loss of key neurons and brain shrinkage that we’re not going to be able to bring back.”
— By Susan Caminiti, special to CNBC.com