Q&A With John McDonough, Executive Chair and CEO of Sunbird Bio

John McDonough
Executive chair and CEO
Sunbird Bio

Sunbird Bio announced a merger with Glympse Bio to accelerate the development of its proprietary protein-based diagnostic technology for Alzheimer’s. John McDonough, executive chair and CEO of Sunbird Bio, spoke with MDT about the merger and the diagnostic tech.

(MDT:) How will this merger impact Sunbird’s tech?

McDonough: We’re excited to have combined forces with Glympse Bio. We believe we’re bringing together two emerging industries leaders in the area of protein-based diagnostics. On the Sunbird side, we have developed and are bringing to market what we believe is the most advanced blood-based test for Alzheimer’s disease called Apex.

There are drugs receiving FDA clearance that clear a protein aggregation that forms in the brain. The protein is named beta-amyloid. Some drugs are targeting another protein called tau, but the beta-amyloid is the primary target. In all of these clinical trials, the only way to detect the aggregation of that protein is by using a PET scan, which is very expensive and fairly inaccessible. These tests are rarely reimbursed and used in the diagnosis of Alzheimer’s disease. Instead, the diagnosis is typically based on cognitive tests.

As the drugs enter the market, and for future clinical trials, there’s a desperate need for a blood-based test that is easy, cost effective, while also providing the equivalent of a PET scan result. There are some blood-based tests out there, but the tricky part of the problem is that we all have low concentrations of beta amyloid in our brains and bloodstream. It's the aggregated sticky form specifically that is the problem that we really nned to be able to detect.

(MDT:) What sort of tests can detect this?

McDonough: No blood test today can detect whether that protein has become sticky. What they’ll do is try and use different ratios of the protein in the bloodstream and try to approximate, but the data is not as good as a PET scan.

We’ve developed an ability to detect whether that protein has become sticky. The reason why we’re able to do that is because our Apex platform is about 10,000 times more sensitive than other detectors. More importantly, it’s based on the detection of extra cellular vesicles or exosomes, which are a byproduct of proteins. What happens is that sticky versions of AB42 will bind to these vesicles in the brain and pass through the blood-brain barrier at low concentration levels.

We have a detector that can specifically detect the extracellular vesicles and the protein, so that we can tell if we’re detecting the form of AB42 that aggregates. This has shown, in a study published in Nature Communications, to be about 90% as effective as a PET scan.

(MDT:) Can this technology be used for other applications?

McDonough: The detector itself is the secret sauce of the intellectual property that we’ve developed. It’s detecting at the nano-meter scale and has a very specific assay and diagnostic format. The ultrasensitive detector, coupled with the ability to have the sticky form of AB42 adhere to the vesicle passing through the blood-brain barrier that gives us the advantage. The detector itself can be used for other applications, such as detecting tau (another protein associated with Alzheimer’s disease), Parkinson’s disease, and several other applications.

With the Glympse platform, the activity of proteases can be detected. This is a completely novel approach to diagnostics. It uses a library of about 800 different proteases that we’re applying to early stage cancer detection and have demonstrated similar correlation in the field of liver cancer.

(MDT:) What makes testing for Alzheimer’s so difficult?

McDonough: There have been a couple of issues. If you look prior to the work that’s been done by Eisai and Eli Lilly, there was a debate around what was the actual source of Alzheimer’s disease. Most people thought that the protein was the culprit, but there was debate about that. Some firms developed medicines targeting the protein, but they didn’t succeed in reducing cognitive decline. These companies proved that they are successful and removing a higher percentage of the AB42 protein, so there’s clearly a threshold in how much you need to remove. Prior to these drugs, there weren’t any treatments.

Now that treatments are emerging, you need a test that can identify what they’re treating (the aggregated AB42 protein), but you also now need a test where you can monitor a patient who’s being treated so that you can see that the drug is working or not and to know when to take a patient off a drug or change dosage levels.

The whole need has shifted in less than a year due to breakthroughs on the drug side. The challenge for other bloodtests is that you’re not just trying to detect the AB42 protein, you need to detect the state of the protein (whether its sticky or not). Many detectors can’t do that and not everything passes through the blood-brain barrier. It’s a very unique case that needs a novel detection method in order to get to see the same thing that you see on an image with a PET scan.