NeuroVoices: Jeff Dage, PhD, on Clinical Implementation of Blood-Based Biomarkers in Alzheimer Disease

Blood-based biomarkers for Alzheimer disease (AD) are rapidly reshaping approaches to diagnosis, risk stratification, and early detection, particularly in the context of emerging disease-modifying therapies. Among these, assays targeting phosphorylated tau epitopes have gained significant attention for their potential to complement clinical evaluation, cerebrospinal fluid (CSF) analysis, and amyloid positron emission tomography. As clinicians increasingly encounter patients with cognitive symptoms, understanding how to incorporate these biomarkers into diagnostic pathways has become a central focus of contemporary AD care.

At the 2026 Alzheimer’s Association International Conference (AAIC), held July 12-15, in London, United Kingdom, a proprietary p-tau217 antibody technology from ALZpath was featured across multiple presentations, underscoring the growing role of this platform in advancing accurate, scalable blood-based diagnostics for AD.¹ These data contributed to a broader evidence base suggesting that p-tau217 assays may offer performance comparable to established CSF measures. Overall, the studies highlighted how industry, academia, and clinical stakeholders are working to refine assay performance, validate clinical use cases, and clarify how blood-based biomarkers can be used responsibly alongside traditional diagnostic tools.

In a new iteration of NeuroVoices, Jeff Dage, PhD, senior research professor of neurology at Indiana University School of Medicine and scientific advisory board member at ALZpath, discussed the evolving landscape of AD biomarkers. Dage reviewed the rapid progress in the field, with particular emphasis on the regulatory clearance of blood-based phosphorylated tau assays and their role as adjuncts to clinician-led diagnosis rather than stand-alone tools. He outlined how these tests may alter diagnostic pathways, improve identification of patients appropriate for disease-modifying therapies, and enhance the efficiency of clinical trials through screening and pharmacodynamic applications.

NeurologyLive: Can you provide an overview of the current state of AD biomarkers, particularly blood-based biomarkers?

Jeff Dage, PhD: The field of AD biomarkers has been changing rapidly just over the last few years with the discovery and development of phosphorylated tau 217 and how that has advanced into the regulatory world and gotten FDA cleared in order to be used in clinical diagnosis. Now, it's important to keep in mind that the clinician is the first line of diagnosis, and the blood test is currently there to aid in that diagnosis. But it has changed a lot, not only in patient care and management, but in terms of being available.

Now it's all about the implementation, and so there's a lot of change going on in how people think about implementing it. I think that implementation piece is probably where I'm seeing the most change and the most discussion. A lot of the science has been worked out, and the tests are performing really well.

What important advances in AD biomarker research do you think practicing clinicians and specialists should be aware of?

Probably the most important thing is what I had mentioned: the FDA clearance of the tests, because I really do think that brings a certain level of validity. So, clinicians now have these tests available. There’s a lot of them. Not all of them perform exactly the same, but there are quite a few choices.

It's really important to understand how to use them. The critical part is to do the clinical diagnosis first, and then use the test to aid in that diagnosis, to look at the etiology of what might be causing the symptoms.

Thinking about the prior probability of an Alzheimer diagnosis versus something else will really help clinicians engage the use of that test in the right way. I think that's probably the biggest thing to learn and to get up to speed on, so it doesn't end up being thought of in the wrong way in terms of how to use this test.

How do you think blood-based AD biomarkers have the potential to change diagnostic pathways for patients who are suspected of having or being at risk of AD?

Over the last probably decade, the diagnosis of AD has been largely just a clinical diagnosis. Only recently have people started using cerebrospinal fluid tests or amyloid PET imaging, and those are pretty infrequent because of availability and accessibility. Also, there wasn't as much of a need without the treatments. With the treatments becoming more available, understanding who has AD in terms of the amyloid pathologies really makes a big difference.

These care pathways are going to be enabled by the easy accessibility of the blood tests, and that blood test performance is on par with CSF testing. So, I think blood tests will be able to be a first line of aiding in that diagnosis. Once you have symptoms and they're diagnosed, you can aid that diagnosis by understanding the etiology and help that pathway determine which way to go—towards treatments or not towards treatments—and guide follow-up management, care, and further diagnostic work-up in terms of where there might be co-pathologies and things like that.

As biomarkers are increasingly incorporated into AD clinical trials, how have these tools changed the way researchers design studies?

I think that's one of the things I was most excited about when we were first discovering these tests, because I was working in a pharmaceutical company at the time, is: how do these enable more efficient clinical trials?

Really, that's what it's about. The clinical trial efficiency becomes a lot better. The costs go down. The time to enrollment can go up, and so you can afford to run more trials. And what that means, as a scientist, is you can do more experiments and understand which treatments might be able to advance the quickest.

I think biomarker use as a screening tool to enable efficient trials is one thing. But then you can think about other uses like target engagement or pharmacodynamic biomarker use, where you're looking at: does the drug get to the target, and does the drug do what it's supposed to do? That's really what pharmacodynamics is all about.

You can see that use, and that can make really efficient phase 1b or phase 2 clinical trials. If you have really good pharmacodynamic biomarkers, they'll help you understand that mechanistic hypothesis and help you understand and set the dose that you want to move forward with. So, they are really valuable, and there are a lot of biomarker choices now and a lot of platforms for use in clinical trials.

What directions do you see as most important for future biomarker development?

I think the biggest direction I hope it goes is developing novel biomarkers for other pathologies, other etiologies. A lot of the patients that are presenting with clinical symptoms will have multiple pathologies in their brain. The AD amyloid and neurofibrillary tangles of tau are just 2 of those pathologies. People could have synuclein or Lewy body pathology, TDP-43, even vascular pathology that might be contributing to symptoms.

We don't have biomarkers for all of those things—good biomarkers, fluid-based biomarkers, or affordable biomarkers. I think that area is where a lot of the research is going, and I hope it goes that way. In the meantime, we have a lot of great new platforms that enable multiple tests and ultra-sensitive tests, and I think that'll help advance our learnings as we conduct that science.

Is there anything else you would like to add about the use of AD biomarkers in practice or in clinical research?

When I think about this field, where it's going, and what I hear, one of the things that I think is really important to me is that clinicians in specialty care, primary care, family medicine, at all different levels, if they're considering or already diagnosing patients dementia living with dementia, I think it's really important to consider how to use this test and how to use it in the right way.

We don't want to overdiagnose. Some people who don't have symptoms might have a positive blood test. While we're trying to detect those that actually are living with mild cognitive impairment and might benefit from those treatments that are becoming available. We don't want to do the blood test and then stop trying to understand what all the other things are that could be causing the symptoms.

I think that's probably the biggest thing that I really want people to learn and to think about is the right way to use these tests. Then, for people who have never diagnosed people with mild cognitive impairment before and are going to start, take the time to get trained. Take the time to really understand how to use it.

Come to these events like AAIC and really understand how to do this in the best way possible because what this test does in terms of enabling us to detect the disease is an incredible advancement for people who are just starting to experience symptoms. They don't have to wait until they reach the stage of dementia.

I think that's going to be a critical thing is detecting it early to get the best outcome possible with the treatments. That won't happen if physicians are untrained or aren't aware. It just won't happen, to detect the disease and diagnose it appropriately fast enough. So, I really hope that people will take the time to really learn all about it.

Transcript edited for clarity. Click here for more coverage of AAIC 2026.

REFERENCES
1. ALZpath Demonstrates Global Clinical Impact at AAIC 2026, with Proprietary pTau217 Antibody Anchoring 86 Presentations Demonstrating Clinical and Diagnostic Value Across the Translational Pipeline. News release. ALZpath. July 13, 2026. Accessed July 14, 2026. https://alzpath.bio/alzpath-demonstrates-global-clinical-impact-at-aaic-2026-with-proprietary-ptau217-antibody-anchoring-86-presentations-demonstrating-clinical-and-diagnostic-value-across-the-translational-pipeline/