But recent paradigm shifts, spurred by a BrightFocus-sponsored 2014 conference, have many researchers starting to focus on attacking Alzheimer’s as early as possible, even during the decades-long ‘prodromal’ phase—the period during which biochemical changes have started to occur in the brain but symptoms have not yet started to appear. New drugs, targeted towards Alzheimer’s at these earliest stages, are being introduced to slow the progression of the disease and offer new hope that goes beyond the reach of all currently approved treatments.
What Does the Latest Research Show?
Up until now, Alzheimer’s has been thought of largely as a disease that begins when symptoms start to show. Unfortunately, there are no treatments to slow the course of the disease once it hits this point--only to treat the effects of these systems. Now, new research and clinical science are coming together to describe Alzheimer’s as a continuum, with a virtually invisible “preclinical” stage that might last a decade or longer and begins with no symptoms and even no cellular changes that could be picked up on a biomarker. The end of this phase is marked by changes that can be detected through testing but show no other outward presentations--in fact, up until this point the disease is virtually indistinguishable from the profile of typical aging.
The next phase, known as “prodromal” Alzheimer’s, equates with a condition now known as mild cognitive impairment (MCI) and may hold the sweet spot for the latest developments in Alzheimer’s treatment.
But even with these exciting breakthroughs, it may be difficult to quantitatively measure the effectiveness of these new preclinical disease-modifying drugs.
Why Is It Difficult to Quantify Treatment Effectiveness?
Because early stage Alzheimer’s is so difficult to detect, there is debate about how best to measure the effectiveness of preclinical disease-modifying drugs—especially using traditional yardsticks. A variety of alternative measurements have been proposed, ranging from purely physiologic effects, such as amyloid beta accumulation and hippocampal atrophy, to cognition changes, assessments of social functioning, and things like self care and independence (sometimes referred to as "activities of daily living", or ADL), and behavioral factors like agitation and anxiety. However, opinions differ about how "clinically meaningful" each of these endpoints would be, and there are questions of reliability, variability, and other uncertainties.
The Future of Alzheimer’s Treatment
Even as researchers work to determine a system to measure the effectiveness of new drugs, it’s apparent that the rule book for Alzheimer’s treatment is changing. Trials designed to test disease-modifying Alzheimer's drugs will probably look a lot different from your typical Phase 3 clinical trials, and may include things like online cognitive self-assessments, caregiver input, measuring functional well-being in addition to cognitive changes, and continued efforts to account for variables—apart from treatment success or failure—that may affect a person’s clinical outcome.
This Promising Science article is excerpted from a longer article by BrightFocus Health and Science Writer Martha Taggart, "BrightFocus-Funded Discovery Could Lead to Drugs that Slow Alzheimer's Disease Progression."
BrightFocus is a part of the Accelerate Cure/Treatments for Alzheimer’s Disease (ACT-AD) coalition, committed to advancing the fields of research in Alzheimer’s treatment. We are proud to sponsor events such as the conference described above and other events, studies, and efforts to move us closer to a cure. If you’d like to read more about the latest breakthroughs in Alzheimer’s research, or breakthroughs in glaucoma or macular degeneration, visit the research we fund section.
This content was last updated on: June 29, 2015