Breaking News
May 3, 2019 - Vaping and Smoking May Signal Greater Motivation to Quit
May 3, 2019 - Dementia looks different in brains of Hispanics
May 3, 2019 - Short-Staffed Nursing Homes See Drop In Medicare Ratings
May 3, 2019 - Study of teens with eating disorders explores how substance users differ from non-substance users
May 3, 2019 - Scientists develop new video game that may help in the study of Alzheimer’s
May 3, 2019 - Arc Bio introduces Galileo Pathogen Solution product line at ASM Clinical Virology Symposium
May 3, 2019 - Cornell University study uncovers relationship between starch digestion gene and gut bacteria
May 3, 2019 - How to Safely Use Glucose Meters and Test Strips for Diabetes
May 3, 2019 - Anti-inflammatory drugs ineffective for prevention of Alzheimer’s disease
May 3, 2019 - Study tracks Pennsylvania’s oil and gas waste-disposal practices
May 3, 2019 - Creating a better radiation diagnostic test for astronauts
May 3, 2019 - Vegans are often deficient in these four nutrients
May 3, 2019 - PPDC announces seed grants to develop medical devices for children
May 3, 2019 - Study maps out the frequency and impact of water polo head injuries
May 3, 2019 - Research on Reddit identifies risks associated with unproven treatments for opioid addiction
May 3, 2019 - Good smells may help ease tobacco cravings
May 3, 2019 - Medical financial hardship found to be very common among people in the United States
May 3, 2019 - Researchers develop multimodal system for personalized post-stroke rehabilitation
May 3, 2019 - Study shows significant mortality benefit with CABG over percutaneous coronary intervention
May 3, 2019 - Will gene-editing of human embryos ever be justifiable?
May 3, 2019 - FDA Approves Dengvaxia (dengue vaccine) for the Prevention of Dengue Disease in Endemic Regions
May 3, 2019 - Why Tonsillitis Keeps Coming Back
May 3, 2019 - Fighting the opioid epidemic with data
May 3, 2019 - Maggot sausages may soon be a reality
May 3, 2019 - Deletion of ATDC gene prevents development of pancreatic cancer in mice
May 2, 2019 - Targeted Therapy Promising for Rare Hematologic Cancer
May 2, 2019 - Alzheimer’s disease is a ‘double-prion disorder,’ study shows
May 2, 2019 - Reservoir bugs: How one bacterial menace makes its home in the human stomach
May 2, 2019 - Clinical, Admin Staff From Cardiology Get Sneak Peek at Epic
May 2, 2019 - Depression increases hospital use and mortality in children
May 2, 2019 - Vicon and NOC support CURE International to create first gait lab in Ethiopia
May 2, 2019 - Researchers use 3D printer to make paper organs
May 2, 2019 - Viral infection in utero associated with behavioral abnormalities in offspring
May 2, 2019 - U.S. Teen Opioid Deaths Soaring
May 2, 2019 - Opioid distribution data should be public
May 2, 2019 - In the Spotlight: “I’m learning every single day”
May 2, 2019 - 2019 Schaefer Scholars Announced
May 2, 2019 - Podcast: KHN’s ‘What The Health?’ Bye-Bye, ACA, And Hello ‘Medicare-For-All’?
May 2, 2019 - Study describes new viral molecular evasion mechanism used by cytomegalovirus
May 2, 2019 - SLU study suggests a more equitable way for Medicare reimbursement
May 2, 2019 - Scientists discover first gene involved in lower urinary tract obstruction
May 2, 2019 - Researchers identify 34 genes associated with increased risk of ovarian cancer
May 2, 2019 - Many low-income infants receive formula in the first few days of life, finds study
May 2, 2019 - Global study finds high success rate for hip and knee replacements
May 2, 2019 - Taking depression seriously: What is it?
May 2, 2019 - With Head Injuries Mounting, Will Cities Put Their Feet Down On E-Scooters?
May 2, 2019 - Scientists develop small fluorophores for tracking metabolites in living cells
May 2, 2019 - Study casts new light into how mothers’ and babies’ genes influence birth weight
May 2, 2019 - Researchers uncover new brain mechanisms regulating body weight
May 2, 2019 - Organ-on-chip systems offered to Asia-Pacific regions by Sydney’s AXT
May 2, 2019 - Adoption of new rules drops readmission penalties against safety net hospitals
May 2, 2019 - Kids and teens who consume zero-calorie sweetened beverages do not save calories
May 2, 2019 - Improved procedure for cancer-related erectile dysfunction
May 2, 2019 - Hormone may improve social behavior in autism
May 2, 2019 - Alzheimer’s disease may be caused by infectious proteins called prions
May 2, 2019 - Even Doctors Can’t Navigate Our ‘Broken Health Care System’
May 2, 2019 - Study looks at the impact on criminal persistence of head injuries
May 2, 2019 - Honey ‘as high in sugars as table sugar’
May 2, 2019 - Innovations to U.S. food system could help consumers in choosing healthy foods
May 2, 2019 - FDA Approves Mavyret (glecaprevir and pibrentasvir) as First Treatment for All Genotypes of Hepatitis C in Pediatric Patients
May 2, 2019 - Women underreport prevalence and intensity of their own snoring
May 2, 2019 - Concussion summit focuses on science behind brain injury
May 2, 2019 - Booker’s Argument For Environmental Justice Stays Within The Lines
May 2, 2019 - Cornell research explains increased metastatic cancer risk in diabetics
May 2, 2019 - Mount Sinai study provides fresh insights into cellular pathways that cause cancer
May 2, 2019 - Researchers to study link between prenatal pesticide exposures and childhood ADHD
May 2, 2019 - CoGEN Congress 2019: Speakers’ overviews
May 2, 2019 - A new strategy for managing diabetic macular edema in people with good vision
May 2, 2019 - Sagent Pharmaceuticals Issues Voluntary Nationwide Recall of Ketorolac Tromethamine Injection, USP, 60mg/2mL (30mg per mL) Due to Lack of Sterility Assurance
May 2, 2019 - Screen time associated with behavioral problems in preschoolers
May 2, 2019 - Hormone reduces social impairment in kids with autism | News Center
May 2, 2019 - Researchers synthesize peroxidase-mimicking nanozyme with low cost and superior catalytic activity
May 2, 2019 - Study results of a potential drug to treat Type 2 diabetes in children announced
May 2, 2019 - Multigene test helps doctors to make effective treatment decisions for breast cancer patients
May 2, 2019 - UNC School of Medicine initiative providing unique care to dementia patients
May 2, 2019 - Nestlé Health Science and VHP join forces to launch innovative COPES program for cancer patients
May 2, 2019 - Study examines how our brain generates consciousness and loses it during anesthesia
May 2, 2019 - Transition Support Program May Aid Young Adults With Type 1 Diabetes
May 2, 2019 - Study shows how neutrophils exacerbate atherosclerosis by inducing smooth muscle-cell death
May 2, 2019 - Research reveals complexity of how we make decisions
More Alzheimer’s Drug Trial Failures: Are Researchers on the Wrong Track?

More Alzheimer’s Drug Trial Failures: Are Researchers on the Wrong Track?

WEDNESDAY, April 10, 2019 — Amyloid beta has long been a prime suspect in Alzheimer’s disease, since abnormal levels of the protein form disruptive plaques between patients’ brain cells.

But drug trials aimed at lowering amyloid levels have repeatedly failed to save people’s brains, and some researchers now believe the focus needs to shift to other potential culprits.

Researchers pulled the plug early on the latest failed clinical trial, after patients’ brain power continued to decline even though the amyloid beta blocker verubecestat successfully lowered amyloid levels in their brains and spinal fluid.

The disappointing verubecestat results appear in the April 11 issue of the New England Journal of Medicine, alongside a research letter announcing similarly negative preliminary findings from the clinical trial of another amyloid blocker called atabecestat.

These negative results jibe with those of earlier trials, and present “pretty strong evidence that amyloid-lowering is the wrong target,” said Dr. David Knopman. He’s a professor of neurology with the Mayo Clinic who wrote an editorial accompanying the new reports.

Knopman noted that the verubecestat trial showed that amyloid levels declined slightly in the brain and fairly substantially in the spinal fluid following treatment with the drug, but patients’ brain structure wizened and their ability to reason and remember still declined.

“They hit the target and yet people got worse, consistently worse, both in terms of brain structure and brain cognition,” Knopman said.

The odd thing is that amyloid beta plaques remain a “very good marker of Alzheimer’s-related cognitive impairment,” Knopman said. When these plaques are found, it’s very likely the person is suffering from Alzheimer’s.

Because of this, it’s very important that research focused on amyloid beta continues, said Rebecca Edelmayer, director of scientific engagement at the Alzheimer’s Association.

“There’s still a preponderance of evidence that amyloid beta is a hallmark protein of the disease, and I think we need to continue to understand the role it plays in the disease,” said Edelmayer, who wasn’t involved with the studies.

“The trials that are still underway looking at part of the amyloid signaling cascade need to be completed so we can learn from each of these trials, whether there are positive or negative results,” she said.

At the same time, the Alzheimer’s Association has already broadened the scope of its research funding to focus on other means by which the disease could be treated or prevented, Edelmayer said.

Amyloid clinical trial results are all popping up now because, as one of Alzheimer’s key symptoms, amyloid beta plaques were one of the first therapeutic targets to be pursued, she said.

“It makes sense we’re seeing amyloid in the news most frequently because these are the ideas that were started 10 to 15 to 20 years ago,” which is about as long as it takes for science to fully explore such avenues, Edelmayer said.

In the intervening years, many other processes and potential treatment targets have started to be pursued in the quest for a cure.

Research teams still are investigating the role of the other major hallmark of Alzheimer’s disease: the tangles of tau proteins that collect within neurons and potentially harm communication between synapses.

“We know these two hallmarks of the disease are present and helping us define some of those clinical symptoms, but we don’t yet know why these healthy proteins in our brain turn to something that becomes aberrant or pathological or destructive in the brain,” Edelmayer said.

Other treatment targets being investigated include chronic inflammation in the brain, the health of cerebral blood vessels, the role of the immune system and the contribution of genetics, Edelmayer and Knopman said.

“There’s a huge diversity of therapeutic mechanisms that are being looked at,” Knopman said. “We will leave no stone unturned when it comes to this disease.”

Some researchers are also advancing theories by which viruses or bacteria might be the culprit.

A study presented last week at the annual meeting of the American Association of Anatomists argued that the bacteria P. gingivalis, which causes gum disease, could be associated with Alzheimer’s. Other earlier research has drawn a similar potential link to the herpes simplex virus.

The “infection” theory of Alzheimer’s is still in its infancy, however, Knopman noted.

“I do not believe the evidence provides any avenues at this point for treatment other than the obvious sledgehammer of giving antivirals to Alzheimer’s patients, which is hardly justified based on the slimness of the data,” Knopman said.

The verubecestat trial ended in February 2018, a year prior to completion of its first phase, after 1,454 patients had been enrolled, the new report says. A data and safety monitoring committee concluded that the drug would not outperform a placebo at either of two doses being tested.

The atabecestat trial also ended early, in May 2018, due to adverse events related to liver health. The 557 participants are still being tracked as part of a safety follow-up.

More information

The Mayo Clinic has more about brain changes related to Alzheimer’s.

© 2019 HealthDay. All rights reserved.

Posted: April 2019

Tagged with:

About author

Related Articles