Sunbird Bio blood test may yield accurate Parkinson’s diagnosis

Sunbird Bio’s blood test to indirectly detect toxic clumps of alpha-synuclein protein in the brain, a hallmark of Parkinson’s disease, may help yield an accurate Parkinson’s diagnosis, according to data from a clinical study.

The company presented the results in a poster, “Using neural derived EV-bound biomarkers in blood for the accurate classification of alpha synuclein aggregation in the brain,” at the 17th Clinical Trials on Alzheimer’s Disease international conference, held Oct. 29-Nov. 1 in Madrid.

“We’re excited to share the first data from a clinical trial of our proprietary alpha-synuclein biomarker signatures, which validate the potential of our blood-based platform to provide the first clinical diagnostic test for Parkinson’s disease,” John McDonough, Sunbird’s executive chairman and CEO, said in a company press release. “These data also reinforce our technology’s ability to accurately and directly detect a number of aggregated proteins from the brain that are key to the diagnosis of a range of neurological disorders — all with a single blood draw.”

Parkinson’s is marked by the abnormal folding of the alpha-synuclein protein that makes it prone to clumping, or aggregating, into small, insoluble structures called fibrils in the brain, which can then come together to form Lewy bodies. These toxic structures are thought to contribute to Parkinson’s progressive dysfunction and the death of nerve cells that produce dopamine, a chemical messenger involved in motor control.

The gradual loss of dopamine in the brain results in the disease’s motor symptoms, which include slowness of movement, muscle rigidity, tremor, and impaired walking and balance.

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Parkinson’s diagnosis via symptoms, history, exam

No specific blood-based diagnostic tests are available for Parkinson’s, and establishing a diagnosis is mainly based on the patient’s symptoms, medical history, and a detailed physical examination.

Sunbird Bio is developing a potential diagnostic blood test for Parkinson’s. Created with the company’s proprietary APEX platform, the test is designed to predict the presence of alpha-synuclein clumps in the brain by detecting alpha-synuclein clumps bound to brain-derived extracellular vesicles (EVs) in the blood.

EVs are tiny vesicles filled with cargo, like proteins, DNA, and RNAs, that are released by most cells to help coordinate cell-to-cell communication.

According to Sunbird, while alpha-synuclein in the brain may naturally cross the blood-brain barrier, a highly selective membrane that controls what passes between the blood and the brain, alpha-synuclein clumps preferentially bind to EVs. This facilitates their transport within and out of the brain by crossing the blood-brain barrier.

By measuring alpha-synuclein aggregates bound to brain-derived EVs found in blood, the company developed a blood biomarker signature that may better reflect alpha-synuclein clumping in the brain compared with soluble, unbound alpha-synuclein proteins.

Sunbird Bio’s study evaluated the test’s ability to discriminate between EV-bound and unbound alpha-synuclein in the blood of 16 people with Parkinson’s and 24 age-matched, healthy people.

Results showed that while a Sunbird-designed control signature of unbound alpha-synuclein was unable to discriminate patients from healthy controls, the company’s signature of brain-derived EV-bound alpha-synuclein classify was able to do so with 86% accuracy.

The findings could also have important implications for Alzheimer’s disease, another neurodegenerative condition marked by alpha-synuclein aggregation.

“Research has only recently uncovered the pivotal role that alpha synuclein proteins play in the [development] of Parkinson’s disease and Alzheimer’s disease, and the ability to accurately detect the aggregation of these proteins from a blood test could transform how these diseases are diagnosed,” said Huilin Shao, PhD, founder of Sunbird.

The data “support the initiation of additional clinical trials incorporating more biomarkers and a broader array of blood samples to further evaluate our technology’s potential to accurately diagnose Parkinson’s disease and other synuclein-related neurological disorders,” Shao said.

Sunbird is developing tests to detect other aggregated proteins across neurological diseases, including tau and amyloid beta for Alzheimer’s and TDP-43 for Alzheimer’s and amyotrophic lateral sclerosis.