Molecular neuropsychiatry firm Genomind said this week that it has signed an exclusive licensing agreement with Emory University to commercialize blood-based protein biomarkers for Alzheimer's disease.
The deal marks Genomind's entry into both the proteomics and Alzheimer's spaces. To date, the firm has focused primarily on genetic testing for psychiatric disorders. In 2011, it launched its Genecept assay, which provides patient genetic information that physicians can use to guide treatment of conditions including depression, bipolar disorder, schizophrenia, anxiety disorders, obsessive-compulsive disorder, and attention deficit hyperactivity disorder.
The licensing agreement covers analyses — led by Emory researcher William Hu — of Alzheimer's plasma proteome datasets generated by the Alzheimer's Disease Neuroimaging Initiative, Washington University in St. Louis, and the University of Pennsylvania. According to Jay Lombard, chief scientific officer and medical director of Genomind, the company hopes to develop markers for use in an initial screening test for Alzheimer's and as aids for identifying and tracking modifiable risk factors for the disease.
Hu was lead author on a 2012 Neurology paper in which he and other members of the ADNI consortium analyzed more than 1,000 samples from these three datasets, identifying four proteins that appeared to be linked to the disease (PM 8/17/2012).
Using Rules-Based Medicine's (now Myriad RBM) Human DiscoveryMAP immunoassay platform, the researchers measured levels of 190 proteins in a 333-patient cohort collected by clinicians at Washington University, and in a separate 267-patient cohort, collected by researchers at the University of Pennsylvania.
A comparison of these two cohorts identified 17 analytes associated with very mild dementia/MCI/Alzheimer's. The researchers then validated these findings via comparison with data from an independent 566-patient ADNI cohort run on the same Human DiscoveryMAP platform, identifying protein apoE, B-type natriuretic protein, C-reactive protein, and pancreatic polypeptide as the four markers that appeared linked to Alzheimer's across all three cohorts.
While these four proteins were the most promising biomarkers to emerge from the Neurology study, Genomind plans to mine the full 190-protein dataset for potentially useful markers, Lombard told ProteoMonitor. He observed that the study's findings were encouraging, however, in that the identified plasma markers appeared to track with the cerebrospinal fluid markers β-amyloid and tau, currently the gold standards of Alzheimer's protein biomarkers.
Given that result, Lombard said that Genomind envisions building a panel that could help determine if patients should be passed on for CSF marker analysis via lumbar puncture. Currently, he said, patients without "overt clinical symptoms of cognitive dysfunction" are typically put under observation, receiving additional assessments every six months to a year.
"This is the wrong approach," Lombard said, suggesting that such patients could potentially be helped by earlier intervention.
"The idea is to make available a low cost protein-based test to allow us to identify patients who are at higher risk [of Alzheimer's] and thereby triage them to the appropriate neurological centers to allow for decisions on further diagnostic work-up and interventions," he said.
Additionally, Lombard said, the markers could prove useful in identifying and assessing patient interventions.
For instance, he said, the licensed data suggests that "many of the conventional risk factors that are usually associated with cardiovascular disease and metabolic syndrome also have significant overlap with [Alzheimer's]."
Such findings, he said, argue against what he called the "therapeutic nihilism" common in discussions of Alzheimer's diagnosis – the notion that "if I'm at risk of Alzheimer's or I have MCI, there is really nothing you can offer me."
"That many of those risk factors are identified by protein biomarkers opens up the possibility that applying very low tech and uncomplicated interventions based on recognition of these biomarkers could potentially mitigate progression of the disease," he noted.
Additionally, the markers could provide physicians with "a tool to longitudinally assess [such] interventions," Lombard said.
Genomind also plans to apply the markers to more conventional drug development work, he said. Biomarkers are seen as potentially key tools for the selection of clinical trial cohorts in Alzheimer's drug development. Past Alzheimer's drug failures have been blamed on the use of cohorts too far along in disease progression to respond well to therapy. This notion has led to the hope that better results might be obtained by testing patients in earlier stages of the disease.
The CSF markers Aβ and tau have begun making their way into clinical trials for this purpose. Plasma protein markers are desirable, however, because they are easier and less expensive to access than CSF markers.
To date, however, research into Alzheimer's plasma protein markers has met with less success than CSF work. A prominent 2007 Nature Medicine study led by Stanford University researchers identified 18 plasma markers that the authors said could classify Alzheimer's patients with accuracy of close to 90 percent and identify patients that would progress from mild cognitive impairment to Alzheimer's. A subsequent study, however, was unable to reproduce these results (PM 1/30/2012).
In addition to Emory and Genomind, a number of other parties are pursuing plasma markers for the disease. Last year, for instance, Proteome Sciences, the UK's National Institute for Health Research, and Millipore completed a 1,000-sample validation study of blood-based Alzheimer's markers, identifying three separate panels – each containing between 11 and 16 proteins – that can distinguish between controls, mild cognitive impairment, and Alzheimer's (PM 3/30/2012).
Also last year, researchers from Australia's University of Newcastle published an analysis of the ADNI plasma protein data, which identified a number of potentially diagnostic protein signatures, including a 10-analyte panel that distinguished between controls and mild cognitive impairment patients who progressed to Alzheimer's with sensitivity and specificity of roughly 90 percent (PM 4/6/2012).
In May, a different team of Australian researchers identified a set of plasma proteins that could help predict patient levels of the Alzheimer's disease-associated molecule beta-amyloid (PM 5/3/2013).
Lombard declined to say whether Genomind would commercialize tests emerging from the Emory licensing deal as laboratory-developed tests or submit them to the US Food and Drug Administration for 510(k) clearance. The company offers its Genecept test out of its CLIA lab.