CAMBRIDGE, Mass.– Sunbird Bio, a biotechnology company developing blood-based technologies for diagnosing and treating neurological disorders, presented new clinical data demonstrating that its sunbird αSyn assay accurately detected extracellular vesicle (EV)-bound aggregated alpha-synuclein from a simple blood draw. The results were shared in an oral presentation at the 18th annual Clinical Trials on Alzheimer’s Disease (CTAD) conference held December 1–4, 2025, in San Diego.
“We continue to build strong clinical evidence for our sunbird αSyn assay, which has repeatedly shown accurate detection of Parkinson’s disease from a blood sample,” said Richard Batrla, M.D., Ph.D., MBA, chief medical officer of Sunbird Bio. “These latest data reinforce that detecting post-translationally modified α-synuclein in plasma may help identify patients with related neurological conditions exhibiting α-synuclein co-pathology, supporting differential diagnosis and clinical trial stratification. We look forward to continued development of this technology and advancing its validation in additional clinical studies across biomarkers.”
The new findings come as there are currently no approved blood-based diagnostics for Parkinson’s disease. Sunbird Bio’s approach focuses on directly detecting EV-bound, aggregated alpha-synuclein proteins, which are more closely associated with brain pathology than unbound soluble forms.
Researchers evaluated the assay in three independent feasibility cohorts:
Cohort 1 included 34 early-stage Parkinson’s disease patients and 21 age-matched controls.
Cohort 2, an exploratory group, included 32 symptomatic Parkinson’s disease patients and 12 healthy individuals tested with an assay targeting an additional disease-associated post-translationally modified αSyn marker.
Cohort 3, a confirmatory cohort, included 41 symptomatic Parkinson’s disease patients and 39 age- and gender-matched controls evaluated with the same disease-associated marker used in Cohort 2.
Across all cohorts, investigators assessed the ability of the proprietary EV-based αSyn assay to distinguish between EV-bound and unbound soluble α-synuclein in plasma. The assay accurately classified Parkinson’s-positive samples with an average AUC of 0.814, indicating strong diagnostic performance. By contrast, soluble α-synuclein markers showed weak results, with an AUC of 0.534. According to the company, the findings highlight the importance of EV-bound α-synuclein as a more clinically meaningful indicator of disease biology.
The results may extend beyond Parkinson’s disease. Because α-synuclein aggregation is also present in other neurological conditions, including Alzheimer’s disease, the company believes its diagnostic platform could support broader disease detection, therapy development and patient stratification.
“Currently, there are no specific blood-based tests available for Parkinson’s disease, and a diagnosis is typically made based on symptoms, medical history and physician examination,” said Vijay Parthasarathy, Ph.D., MBA, chief product and strategy officer of Sunbird Bio. “There is a pressing need for blood-based diagnostics that enable early detection, disease monitoring and therapeutic stratification in synucleinopathies, and these encouraging results highlight the potential of our technology to meet that need for physicians and patients.”
Sunbird Bio’s αSyn diagnostic technology directly detects and measures EV-bound aggregated proteins in blood. The company’s expanding clinical evidence continues to show the promise of its platform as an accessible tool for disease detection, drug development, disease monitoring and personalized treatment selection in Parkinson’s disease, Alzheimer’s disease and other neurological disorders.
