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Takeda and Zinfandel Pharmaceuticals Initiate Phase 3 TOMMORROW Trial of AD-4833 for the Delay of Onset of Mild Cognitive Impairment Due to Alzheimer’s Disease in Subjects Selected Using a Genetic-Based Biomarker Risk Assignment Algorithm

Takeda Pharmaceutical Company Limited (“Takeda”) and its partner, Zinfandel Pharmaceuticals, Inc. (“Zinfandel”), recently announced the initiation of TOMMORROW, a global Phase 3 clinical trial investigating a genetic-based biomarker risk assignment algorithm (risk assignment algorithm) to predict risk of mild cognitive impairment (MCI) due to Alzheimer’s disease (AD) within a five year period and to evaluate the efficacy of the investigational low dose pioglitazone (designated AD-4833 for this use) in delaying the onset of MCI due to AD in cognitively normal individuals at high risk as determined by the risk assignment algorithm.

The risk assignment algorithm is comprised of apolipoprotein E (APOE) and TOMM40 genotypes and age. Age and APOE genotype have previously been shown to indicate elevated risk of AD. The addition of TOMM40 is hypothesized to further refine the risk determination.

“To date, there have been a number of avenues investigated with the goal of altering the course of Alzheimer’s disease but results have been unsuccessful,” said Allen Roses, M.D., Chief Executive Officer, Zinfandel. “This is why the TOMMORROW trial is important. The potential to identify an individual’s risk for developing MCI due to AD warrants further investigation.”

AD is a devastating disease and diagnoses are increasing as the world’s population ages. Currently 35.6 million people worldwide are living with some form of dementia. Studies show that individuals with MCI are at an increased risk of developing AD or another dementia with conversion rates of approximately 15 percent per year.

“AD-4833 is a member of a class of drugs known as PPAR (peroxisome proliferator-activated receptor)-gamma agonists which available data show may have a beneficial role in delaying symptoms of MCI due to AD,” noted Stephen Brannan, M.D., Central Nervous System Development Therapeutic Area Head, Takeda. “TOMMORROW is a significant study and represents a novel clinical milestone and trial for the Alzheimer’s community as it evaluates pre-symptomatic patients.”

Source: Taleda Pharmaceutical Company Limited

Researchers Agree that Alzheimer’s Test Results Could be Released to Research Participants

A leading group of Alzheimer’s researchers contends that, as biomarkers to detect signals of the disease improve at providing clinically meaningful information, researchers will need guidance on how to constructively disclose test results and track how disclosure impacts both patients and the data collected in research studies. A survey conducted by a group including experts from the Perelman School of Medicine at the University of Pennsylvania found that a majority of Alzheimer’s researchers supported disclosure of results to study participants. The study is published online in Neurology.

“While this is not a call to immediately tell subjects their biomarker results, it does show that the field is moving to a point where experts want to share valid and meaningful results with participants,” said co-senior author Jason Karlawish, MD, professor of Medicine and Medical Ethics and Health Policy. “As we gain more data on the predictive abilities of these measurements, we will need models and methods to effectively reveal results.”

The study surveyed 139 Alzheimer’s clinical trial leaders and coordinators from the Alzheimer’s Disease Neuroimaging Initiative (ADNI) in April 2012, just before the U.S. Food and Drug Administration approved the amyloid-binding radiotracer known as Amyvid (florbetapir). 73 percent of respondents supported disclosing amyloid imaging results to study participants with mild cognitive impairment, whereas 58 percent supported giving amyloid imaging results to those with normal cognition.

Six themes emerged from the survey, regarding participant preferences and cognition levels, researchers’ requests to develop standardized counseling procedures, participant education, and standardization of data-gathering, and concerns regarding potential harms and benefits to participants, as well as the ways disclosure could impact study results.

Currently, ADNI has a policy to not disclose results to participants, but the survey showed a growing trend of experts who would favor revising this policy. In addition to finding amyloid imaging results valuable, Alzheimer’s experts also valued other biomarker data collected in ADNI, such as spinal fluid tests, PET imaging, and other psychometric tests, suggesting that if amyloid imaging results were allowed to be disclosed, it would likely lead to disclosure of other test results.

Study: Using AD biomarker research results for clinical care [Neurology] 

Source: EurekAlert!

Elevated Levels of Copper in Amyloid Plaques Associated with Neurodegeneration in Mouse Models of AD

Metals such as iron, copper, and zinc are important for many biological processes. In recent years, studies have shown that these nutritionally-essential metals are elevated in human Alzheimer’s disease (AD) brains and some animal models of AD. Scientists are now exploring whether these metals are causing the neurodegeneration seen in AD or are indicative of other ongoing pathologic processes.

In a new study, investigators used synchrotron x-ray fluorescence microscopy to image metal ions in the brain, focusing on the amyloid plaques that are the hallmark of AD. They found that, in two AD mouse models that exhibit neurodegeneration, the plaques contained about 25% more copper than an AD mouse model that shows little neurodegeneration. Looking at other metals, they found that none of the mouse models had significant increases in iron and very little increases in zinc. Metal content was not related to the age of the plaque. The study is reported in the current issue of Biomedical Spectroscopy and Imaging.

“Since excess copper should not be ‘free’ in the brain to bind to the plaques, these data suggest that the cellular control of copper is altered in AD, which may lead to toxic reactions between free copper ions and neurons,” comments lead investigator Lisa M. Miller, PhD, a biophysical chemist in the Photon Sciences Directorate at Brookhaven National Laboratory. In previous work, Dr. Miller’s group found very high levels of copper in human AD plaques.

Since elevated iron in the AD brain is well documented in both human brains and AD mouse models, the researchers measured iron content in the cortex of all three mouse models. They found that iron content was doubled in all AD mouse model cortices compared to controls, whether or not the models showed neurodegeneration. Upon further investigation, spectroscopic data revealed that the excess iron was present in the ferric (oxidized) state and consistent with the iron storage protein ferritin. “The increase in iron may be a reflection of changes in metalloprotein content and metal storage within the brain that is not well understood,” says Dr. Miller.

Nevertheless, since iron in ferromagnetic and detectable through MRI, Dr. Miller suggests that in the future iron may be used as a biomarker for AD at early stages of disease, even before plaques are formed.

Source: Elevated copper in the amyloid plaques and iron in the cortex are observed in mouse models of Alzheimer’s disease that exhibit neurodegeneration [Biomedical Spectroscopy and Imaging]

Source: EurekAlert!

Spinal Fluid Biomarkers of AD and Brain Functional Network Integrity on Imaging Studies

Both Aß and tau pathology appear to be associated with default mode network integrity before clinical onset of Alzheimer disease (AD), according to a study by Liang Wang, M.D., and colleagues at Washington University in St. Louis, Missouri.

Accumulation of Aß and tau proteins, the pathologic hallmarks of AD, starts years before clinical onset. Pathophysiological abnormalities in the preclinical phase of AD may be detected using cerebrospinal fluid (CSF) or neuroimaging biomarkers, according to the study background.

A total of 207 older adults with normal cognition participated in the cross-sectional group study. Researchers examined the relationship between default mode network integrity and cerebrospinal fluid biomarkers of Alzheimer disease pathology in cognitively normal older individuals using resting-state functional connectivity magnetic resonance imaging.

According to the study results, decreased cerebrospinal fluid Aß42 and increased cerebrospinal fluid phosphorylated tau181 were independently associated with reduced default mode network integrity, with the most prominent decreases in functional connectivity observed between the posterior cingulate and medial temporal regions (regions of the brain associated with memory). Observed reductions in functional connectivity were unattributable to age or structural atrophy in the posterior cingulate and medial temporal areas.

Study: Cerebrospinal Fluid Aβ42, Phosphorylated Tau181, and Resting-State Functional Connectivity [JAMA Neurology]

Source: EurekAlert!

New Biomarker Could Reveal Alzheimer’s Disease Years Before Onset

A study published recently reported the identification of what may be the earliest known biomarker associated with the risk of developing Alzheimer’s disease (AD). The results suggest that this novel potential biomarker is present in cerebral spinal fluid (CSF) at least a decade before signs of dementia manifest.

“If our initial findings can be replicated by other laboratories, the results will change the way we currently think about the causes of Alzheimer’s disease,” said Dr. Ramon Trullas, research professor at the CSIC Institute of Biomedical Research of Barcelona and lead author of the study that was published in Annals of Neurology. “This discovery may enable us to search for more effective treatments that can be administered during the preclinical stage.”

Difficult Diagnosis

Alzheimer’s disease affects more than five million Americans and is the sixth leading cause of death in the United States. At present, the only way to accurately diagnose the disease is by post-mortem neuropathological analysis. The relationship of currently known biomarkers with the cause of the disease is unclear, making it nearly impossible to diagnose preclinical stages of the disease with any real certainty.

The CSIC researchers demonstrated that a decrease in the content of mitochondrial DNA (mtDNA) in CSF may be a preclinical indicator for Alzheimer’s disease; furthermore, there may be a directly causative relationship. The hypothesis is that decreased mtDNA levels in CSF reflect the diminished ability of mitochondria to power the brain’s neurons, triggering their death. The decrease in the concentration of mtDNA precedes the appearance of well-known biochemical Alzheimer’s biomarkers (the Aβ1-42, t-tau, and p-tau proteins), suggesting that the pathophysiological process of Alzheimer’s disease starts earlier than previously thought and that mtDNA depletion may be one of the earliest predictors for the disease.

In addition to enabling an investigation of the potential causal relationship of mtDNA and Alzheimer’s progression, the use of mtDNA as an index of preclinical Alzheimer’s disease provides an important advantage over previous biochemical markers: the detection of this novel nucleic acid biomarker is unhampered by the technical difficulties associated with protein detection. mtDNA can be readily quantified by real-time quantitative PCR (qPCR) or droplet digital PCR (ddPCR).

Quantitation of mtDNA

Prior to this study, researchers had not reported that circulating cell-free mtDNA could be detected in human CSF. But with this study, Dr. Trullas’ team was able to both detect and reproducibly quantitate mtDNA using qPCR, carefully optimized by adhering to the MIQE guidelines.

To validate their qPCR findings, Dr. Trullas’ team used Bio-Rad Laboratories’ QX100™ Droplet Digital™ PCR system. Unlike qPCR assays, the QX100 system provides an absolute quantification of target DNA molecules without the need for a standard curve. In addition, an important factor for their CSF analysis was that the Droplet Digital PCR system did not require sample purification to remove PCR inhibitors, as is necessary for qPCR assays.

“Droplet Digital PCR allowed us to validate our initial qPCR measurements because it provides absolute quantitation at the single-molecule level without relying on a standard curve,” said Dr. Trullas. “As the technology becomes more widely adopted, we anticipate that Droplet Digital PCR will be the future of detecting mtDNA in cerebral spinal fluid.”

Dr. Trullas hopes that other laboratories and hospitals will successfully replicate his group’s research results, confirming that reduced mtDNA levels should be investigated as a possible cause of Alzheimer’s disease. By finding a way to block this degeneration, clinicians may be able to diagnose and treat Alzheimer’s disease before symptoms appear.

Study: Low CSF concentration of mitochondrial DNA in preclinical Alzheimer’s disease [Annals of Neurology]

Source: Bio-Rad