BioArctic AB announced today that the US Food and Drug Administration (FDA) Office of Orphan Products Development has granted orphan drug designation to exidavnemab for the treatment of Multiple System Atrophy (MSA), a rare and fatal neurodegenerative disorder.
The designation, announced on March 17, 2025, represents a significant milestone in addressing the substantial unmet medical need for MSA patients, who currently have no disease-modifying treatment options available.
A Novel Approach to Treating MSA
Exidavnemab is a monoclonal antibody specifically designed to target and eliminate aggregated forms of alpha-synuclein, including oligomers, protofibrils, and fibrillar forms. These protein aggregates are implicated in the pathogenesis of synucleinopathies such as MSA and Parkinson's disease.
The drug's mechanism of action focuses on promoting the clearance of these toxic alpha-synuclein aggregates, potentially reducing their spread and harmful effects throughout the brain. By preserving neuronal function and survival, exidavnemab aims to slow disease progression in MSA patients.
"The orphan drug designation for exidavnemab underscores the critical need for innovative treatments for MSA, a devastating condition with poor prognosis," said Oskar Bosson, VP Communications and IR at BioArctic. "This regulatory milestone will help accelerate our development program for patients who currently have no disease-modifying options."
Understanding Multiple System Atrophy
MSA is characterized by pathological alpha-synuclein aggregation that causes progressive damage to nerve cells in the brain. The disease affects both the central and autonomic nervous systems, leading to severe impairments in balance, movement, and basic autonomic functions including breathing, digestion, and bladder control.
The prognosis for MSA patients is particularly grim, with most surviving only 6 to 10 years after symptoms first appear. Few patients live beyond 15 years post-symptom onset. In the United States, MSA affects fewer than 42,000 individuals, qualifying it as a rare disease under FDA guidelines.
Regulatory Benefits and Development Path
The FDA's Orphan Drug Designation program is designed to encourage the development of treatments for rare diseases affecting fewer than 200,000 people in the United States. For BioArctic, this designation provides several valuable incentives, including:
- Tax credits for qualified clinical trials
- Exemption from prescription drug user fees
- Potential seven-year marketing exclusivity upon FDA approval
These benefits could significantly reduce development costs and accelerate the path to market for exidavnemab, should clinical trials demonstrate safety and efficacy.
BioArctic's Expanding Neurodegenerative Disease Portfolio
The Swedish biopharma company has established itself as a significant player in the neurodegenerative disease space. BioArctic is the originator of Leqembi® (lecanemab), developed in partnership with Eisai and recognized as the world's first drug proven to slow the progression of early Alzheimer's disease.
The company's research portfolio extends beyond MSA and Alzheimer's to include Parkinson's disease, ALS, and enzyme deficiency diseases. Many of BioArctic's development programs utilize its proprietary BrainTransporter™ technology, which enhances drug delivery across the blood-brain barrier.
The Challenge of Synucleinopathies
Synucleinopathies represent a group of neurodegenerative disorders characterized by abnormal accumulation of alpha-synuclein protein in the brain. Besides MSA, this category includes Parkinson's disease and Lewy body dementia.
Exidavnemab's development for MSA could potentially inform treatment approaches for other synucleinopathies, expanding its therapeutic potential beyond this rare disease indication.
Looking Toward Clinical Development
While the orphan drug designation marks an important regulatory milestone, exidavnemab remains an investigational agent. BioArctic has emphasized that there is no guarantee the drug will successfully complete clinical development or gain health authority approval.
The company has not yet disclosed specific timelines for clinical trials in MSA patients, but the orphan designation is expected to facilitate and expedite the development process.
For patients suffering from this rapidly progressive and fatal disease, the development of exidavnemab represents a potential ray of hope in a therapeutic landscape currently devoid of disease-modifying options.
