Experimental Parkinson’s drug PRI-101 has shown promising preclinical results, effectively targeting and disassembling toxic α-synuclein protein aggregates that drive neurodegeneration.

Biotechnology company Priavoid GmbH has announced proof-of-concept data for its lead candidate PRI-101, an orally available peptide drug designed to target the underlying causes of neurodegeneration. The experimental drug has shown encouraging early results in preclinical studies, which raises hopes for a therapy that could slow or even alter the course of conditions like Parkinson’s disease.

The findings will be presented at the International Conference on Alzheimer’s and Parkinson’s Diseases and Related Neurological Disorders 2026 in Copenhagen.

Targeting toxic protein build-up

Parkinson’s disease, which affects more than six million people worldwide, is driven in part by the build-up of misfolded proteins known as α-synuclein. These proteins form toxic aggregates in the brain, contributing to the death of nerve cells and the progression of symptoms.

PRI-101 has been developed using Priavoid’s proprietary ‘detangler’ platform.

PRI-101 has been developed using Priavoid’s proprietary ‘detangler’ platform and is designed to bind to these harmful aggregates and break them apart. By converting them back into non-toxic forms, the drug aims to counteract the disease processes seen not only in Parkinson’s but also in related conditions such as multiple system atrophy and Lewy body dementia.

Promising preclinical findings

In a series of laboratory and animal studies, PRI-101 directly targeted and reduced pathological α-synuclein aggregates across multiple models of Parkinson’s disease.

In vitro experiments showed that the drug could disassemble preformed fibrils of α-synuclein and deactivate their ability to spread, with effects increasing over time and at higher concentrations. Ex vivo studies using post-mortem brain samples from patients with Parkinson’s disease, multiple system atrophy and Lewy body dementia also showed reduced levels of these aggregates.

Notably, in vivo studies found that treatment with PRI-101 was associated with longer median survival compared with placebo.

Further pharmacokinetic testing confirmed that PRI-101 can cross the blood-brain barrier and reach the brain in meaningful concentrations, a critical requirement for neurological treatments.

In more complex models, including human brain organoids and two different mouse models of Parkinson’s disease, the therapy reduced both α-synuclein aggregates and levels of phosphorylated α-synuclein.

Notably, in vivo studies found that treatment with PRI-101 was associated with longer median survival compared with placebo. Both short-term and long-term dosing led to reductions in protein aggregation in the brain, including in the substantia nigra, which is heavily affected in Parkinson’s disease. These changes were accompanied by measurable improvements in behavioural performance.

“Parkinson’s disease affects more than 6 million people worldwide and remains an area of profound unmet medical need, with patients still lacking therapies that meaningfully alter the course of disease,” said Dr Antje Willuweit, Director Preclinical Development at Priavoid GmbH. “Taken together, these preclinical data suggest that PRI-101 has the potential to be a first-in-class therapeutic candidate with disease-modifying potential for Parkinson’s disease and other related synucleinopathies. We look forward to advancing this candidate towards the clinic to address a substantial need for new disease-modifying therapeutic options.”

Next steps towards the clinic

While the findings are still at an early stage, they add to the development of treatments that go beyond symptom management and target the root causes of neurodegenerative disease.

Priavoid plans to continue advancing PRI-101 towards clinical development, with the aim of evaluating its safety and effectiveness in human patients. If successful, the approach could represent a new class of therapies designed to tackle protein aggregation.

Related topics
Bioinformatics, Cell Cultures, Cell-based assays, Drug Discovery, Drug Discovery Processes, In Vitro, Lab Automation, Organoids, Proteomics, Sequencing, Toxicology