It’s a form of dementia that afflicts as many as 5.2 million people in the United States. It has no cure.
And as the population ages, the number of people afflicted with Alzheimer’s disease is expected to quadruple over the next 35 years, according to a study from the Johns Hopkins School of Public Health.
That means that by 2050, 1 in 85 people will be living with the disease.
Now doctors at the Alzheimer’s Disease Center at the University of Kansas Medical Center are hopeful a new drug called Solanezumab, made by Eli Lilly & Co., can delay or even prevent Alzheimer’s.
A Phase 3 trial, which tested efficacy and safety, was published in the New England Journal of Medicine early this year. According to that report, solanezumab was effective in slowing disease progression in mild cases of Alzheimer’s, although not in moderate or advanced cases.
“I’m massively hopeful,” says Michelle Niedens, director of education for the Kansas City chapter of the Alzheimer’s Association. “The general Phase 3 trial proved to be insignificant… but the exciting part was they differentiated based on stage. So those individuals who were in the early part of the disease, early stage, seemed to benefit heavily.”
Delaying onset
Although current treatments can slow cognitive decline in patients already diagnosed with the disease, there are no drugs that can delay or prevent its onset.
“They don’t stop the disease, but they help the symptoms, meaning the memory loss and changes in memory,” says Dr. Jeffrey Burns, a neurologist and co-director of the Alzheimer’s Disease Center.
The symptoms of Alzheimer’s – problems with memory, thinking and behavior that affect the ability to perform daily tasks – get worse as the disease progresses.
The average time from mild to severe disease is six years, but the progression can vary widely.
Caregivers are familiar with the progression, and many are at risk of developing the disease themselves, since it often runs in families.
“My mother died 25 years ago with Alzheimer’s disease, and I was a caregiver,” says Joann Bell, who is currently undergoing screening to participate in the Solanezumab study.
Bell says she didn’t know about her mother’s disease until a neighbor mentioned some odd behavior.
“(The neighbor) wasn’t sure if she knew how to make breakfast,” Bell says. And after Bell’s son visited and found that his grandmother had forgotten to buy food, Bell realized her mother could no longer live on her own.
KU is recruiting patients between the ages of 65 and 85, when Alzheimer’s is usually diagnosed, to be part of its drug trial.
“It’s a clinical trial that’s basically the cutting edge approach to preventing Alzheimer’s disease,” Burns says.
The study is being funded by grants from the National Institutes of Health and Eli Lilly and involves over 50 locations throughout the United States, Canada and Australia.
Clearing out amyloid
To participate, applicants will undergo cognitive screening to make sure they don’t have any early symptoms of Alzheimer’s, such as memory loss.
After that they’ll get a PET scan to see if they have “amyloid plaques” in their brain, a risk factor for the disease. Amyloid is a type of protein, and deposits in the brain have been linked to Alzheimer’s disease.
“We all have amyloid in our body,” Burns says. “… It’s a normal part of us, but when it goes up in the brain, that’s not something you see with everyone. You see it in people with Alzheimer’s disease.”
The ideal candidate would have no signs of early Alzheimer’s disease but would have amyloid plaques.
Whether amyloid causes Alzheimer’s or is a byproduct of the disease is a hotly debated topic among scientists.
“A key point is if somebody has amyloid in their brain, not everybody develops Alzheimer’s,” Burns says. “They’re at higher risk for the disease over the next five to 10 years, but not everybody will get Alzheimer’s… So it’s a risk factor.”
Solanezumab, the drug under study, works by attaching itself to amyloid proteins and making them visible to the immune system. Once the immune system detects it, the body’s natural immune defenses react as they would to bacteria or any other foreign body and clears the amyloid out of the body’s system.
Cause or effect?
The premise of the KU trial is that amyloid does cause Alzheimer’s and if it’s cleared out of the system before it causes any damage, then the disease will be prevented.
“Will it definitively answer the question of whether amyloid causes Alzheimer’s? Probably not definitively, but it’s definitely a test of that hypothesis,” Burns says.
“What’s the role of amyloid in Alzheimer’s? It’s not clear… Is it the smoke or is it the fire? This study will really help us take a big step forward in understanding what is the role and relevance of amyloid.”
As Alzheimer’s disease progresses to “severe,” patients lose the ability to carry on conversation, perform daily tasks such as feed or bathe themselves and respond to their environment. Such patients require full-time care.
“It’s difficult for people to watch this devastating illness that takes your memory, your dignity,” Bell says.
The experience with her mother inspired Bell and her husband to go through screening for the three-year-long KU study.
“My husband and I feel this is a crisis,” Bell says.
“To me information is power,” she adds. “And I’m already exercising and eating right, and if I then would proceed - if I have the amyloid - I know it takes a while for it to develop. And maybe I’ll be one of those to get the drug. Just to be part of the research is so exciting.”
For more information on the international trial visit the Anti-AmyloidTreatment in Asymptomatic Alzheimer’s trial (A4 for short) website. To participate in the Kansas City trial, visit the KU Alzheimer's Disease Center website and search "A-4," or call 913-588-0555
Stefani Fontana is an intern at KCUR.
