Early trials suggest injections of a new “silver bullet” drug might help slow memory loss in people who don’t quite yet have Alzheimer’s, but who have some symptoms and who have the brain-clogging “plaques” that define the disease.
The new drug, called aducanumab, is what’s called a monoclonal antibody. It’s a lab-engineered immune system protein designed to attack a compound called amyloid that, for some reason, builds up and clogs the brains of Alzheimer’s patients.
Some people start to get this buildup for years before they actually have true symptoms of Alzheimer’s. Drugmaker Biogen tried their injections in a group of these people to see if it might be possible to delay or even prevent Alzheimer’s.
"This is the first trial to find significant reduction in the build-up of the hallmark amyloid brain plaques of Alzheimer’s and slowing of decline in memory and thinking abilities in individuals at risk for Alzheimer’s," said Maria Carrillo, scientific officer at the Alzheimer’s Association, which was not involved in the research.
"This is the first trial to find significant reduction in the build-up of the hallmark amyloid brain plaques of Alzheimer’s."
And some tests of memory and brain functions showed those who got the highest doses appeared to lose those functions at a slower rate that people given placebo injections. However, side-effects that include brain swelling trouble some experts.
Biogen released details for 166 patients who have been trying the injections, or dummy injections, for just over a year. The amyloid plaques were reduced noticeably in those who got the two highest doses of the drug, but not in those who got the lowest dose or a placebo.
On one test, called the Mini Mental State Examination or MMSE, patients who got a placebo got about 3 points worse over a year. But those who got the lowest dose of aducanumab worsened by just two points and those who got the highest dose didn’t even lose one point on the test after a year, the company told the 12th International Conference on Alzheimer's and Parkinson's Diseases and Related Neurological Disorders in Nice, France.
The most common side-effect was a type of brain swelling. It seemed to pass once a patient's dose was lowered, Biogen said, but it's a worrying symptom, and was worst in patients given the highest dose. Inflammation of the brain has caused companies to dump some earlier experimental Alzheimer's treatments.
Headache, was common, too, in 22 percent of people who got the drug, compared to five percent of those given placebo.
Dr. Dean Hartley, director of science initiatives at the Alzheimer’s Association, is encouraged to see the effects on cognition, or brain function.
“We think that’s of value, because most of these phase I trials are really just used to determine safety and tolerance,” Hartley told NBC News.
It’s especially important for the Alzheimer’s field, because so many drugs have failed to help the disease at all. Some early vaccines meant to attack early stages of the disease didn't work. One caused dangerous brain inflammation, and another reduced the amyloid but didn’t make patients any better.
“We’ve known we all have beta amyloid in our brains, but we don’t understand why it starts to clump together. The thinking is that clumping is toxic to the brain,” said Hartley. It’s possible this particular drug is homing in better than previous drugs on the amyloid that actually causes symptoms, he said.
More advanced studies will be needed, for sure, Hartley cautions. Drugs often look promising for Alzheimer’s in early stages but don’t look so good once they get into advanced trials.
“I’m not popping the champagne cork yet,” agrees the Alzheimer Association’s Dr. James Hendrix. “We need phase 3 trials for a longer period of time.”
But some companies that had been working on Alzheimer’s drugs have given up. “I think this is another piece that is very important to bringing other pharmaceutical companies back into the field,” Hartley said. “We’re hoping there may be that positive signal that will lead people to believe there is a good investment here.”
Biogen is clearly encouraged and is jumping straight to Phase 3 trials- the last stage of testing before a drug is submitted for Food and Drug Administration approval.
“I’m not popping the champagne cork yet."
“This is the first time an investigational drug for Alzheimer’s disease has demonstrated a statistically significant reduction on amyloid plaque as well as a statistically significant slowing of clinical impairment in patients with prodromal or mild disease,” said Dr. Alfred Sandrock, chief medical officer at Biogen. “Based on these results, we are advancing the aducanumab clinical program to Phase 3 with plans to initiate enrollment later this year.”
Other companies are also developing monoclonal antibodies for Alzheimer's. Biogen's share price headed up Friday after the news was released, which suggests investors think it's a good bet.
Experts project that the number of Americans living with Alzheimer’s will triple in the next 40 years, which means that 13.8 million will have the mind-robbing disease by 2050. It’s the sixth leading cause of death in the United States, directly implicated in more than 83,000 deaths each year.
There’s no cure and treatments are very poor. Doctors hope that people can find better ways to prevent it, to blunt the effects of what will otherwise be a tsunami of disease. They're also looking at ways to test early for signs of Alzheimer's, in case it's easier to treat before people even develop symptoms.
For now, people have a few options to try and prevent the disease—including exercise, a little brain training and a healthy diet.