UB-312

UB-312 is an experimental therapeutic vaccine developed by Vaxxinity designed to target [alpha-synuclein](/proteins/alpha-synuclein) for the treatment of [Parkinson's disease](/diseases/parkinsons-disease) and related synucleinopathies including [multiple system atrophy](/diseases/multiple-system-atrophy) (MSA) and [dementia with Lewy bodies](/diseases/dementia-lewy-bodies). The vaccine is a synthetic peptide immunogen that induces the host immune system to produce antibodies against pathological alpha-synuclein species[@pagAN2023].

Background and Rationale

Alpha-Synuclein Pathology in Parkinson's Disease

[Parkinson's disease](/diseases/parkinsons-disease) is characterized by the progressive degeneration of dopaminergic neurons in the [substantia nigra pars compacta](/brain-regions/substantia-nigra), with Lewy bodies—intracellular inclusions primarily composed of misfolded alpha-synuclein—being the hallmark pathological feature[@spillantini1997]. The alpha-synuclein protein, encoded by the [SNCA](/genes/snca) gene, is normally a soluble monomeric protein enriched in presynaptic terminals where it regulates synaptic vesicle trafficking and neurotransmitter release[@chesselet2008].

UB-312 is an experimental therapeutic vaccine developed by Vaxxinity designed to target [alpha-synuclein](/proteins/alpha-synuclein) for the treatment of [Parkinson's disease](/diseases/parkinsons-disease) and related synucleinopathies including [multiple system atrophy](/diseases/multiple-system-atrophy) (MSA) and [dementia with Lewy bodies](/diseases/dementia-lewy-bodies). The vaccine is a synthetic peptide immunogen that induces the host immune system to produce antibodies against pathological alpha-synuclein species[@pagAN2023].

Background and Rationale

Alpha-Synuclein Pathology in Parkinson's Disease

[Parkinson's disease](/diseases/parkinsons-disease) is characterized by the progressive degeneration of dopaminergic neurons in the [substantia nigra pars compacta](/brain-regions/substantia-nigra), with Lewy bodies—intracellular inclusions primarily composed of misfolded alpha-synuclein—being the hallmark pathological feature[@spillantini1997]. The alpha-synuclein protein, encoded by the [SNCA](/genes/snca) gene, is normally a soluble monomeric protein enriched in presynaptic terminals where it regulates synaptic vesicle trafficking and neurotransmitter release[@chesselet2008].

In Parkinson's disease, alpha-synuclein undergoes a conformational transformation from its native disordered state to beta-sheet-rich fibrils that accumulate as Lewy bodies and Lewy neurites throughout the nervous system[@kuPIA2015]. These pathological aggregates are believed to spread in a prion-like manner from affected brain regions to interconnected neural circuits, underlying the progressive nature of the disease[@berger2019].

Therapeutic Approach: Active Immunization

Active immunization with an alpha-synuclein vaccine represents a novel disease-modifying strategy with several potential advantages over monoclonal antibody approaches[@bjorklund2020]:

Mechanism of Action

Vaccine Design

UB-312 is a synthetic peptide vaccine composed of a modified alpha-synuclein epitope conjugated to the carrier protein CRM197 (a non-toxic diphtheria toxin mutant)[@schrots2022]. The vaccine design incorporates several key features:

Epitope Selection

The vaccine targets the C-terminal region of alpha-synuclein (amino acids 110-130), chosen for several reasons[@weihofen2020]:

• Immunogenicity: The C-terminus is intrinsically disordered and highly accessible to antibody binding
• Pathological relevance: Antibodies against this region can recognize both monomers and aggregated forms
• Safety: The epitope is distinct from the NAC (non-Aβ component) region involved in aggregation nucleation
• Selective targeting: Enables binding to toxic oligomers without affecting physiological monomeric function

Carrier Protein (CRM197)

The peptide is conjugated to CRM197, a well-characterized carrier protein used in multiple FDA-approved vaccines. CRM197 provides:

• T-cell help for robust antibody responses
• Enhancement of immunogenicity
• Established safety profile in human vaccines
• MHC-II presentation for CD4+ T-cell activation

Antibody Response

Following immunization, UB-312 induces a polyclonal antibody response targeting [@orourke2015]:

The vaccine-induced antibodies are designed to neutralize circulating alpha-synuclein species, enhance peripheral clearance via the mononuclear phagocyte system, and prevent cell-to-cell transmission of pathological aggregates[@masliah2011].

Clinical Development

Phase 1 Trial (NCT04075318)

The first-in-human Phase 1 study of UB-312 was conducted in patients with clinically diagnosed [Parkinson's disease](/diseases/parkinsons-disease)[@pagAN2023].

Study Design

• Sponsorship: Vaxxinity (formerly United Neuroscience)
• Phase: Phase 1
• Enrollment: Approximately 40 patients with mild to moderate PD (Hoehn & Yahr stages 1-3)
• Dose escalation: Multiple dose groups evaluated (low, medium, high)
• Primary endpoints: Safety and tolerability
• Secondary endpoints: Immunogenicity (antibody response)

Key Results

The Phase 1 trial demonstrated[^1][^2][^3][^4]:

| Endpoint | Result |
|----------|--------|
| Safety | Well-tolerated at all dose levels |
| Immunogenicity | 94% of participants produced anti-alpha-synuclein antibodies |
| Antibody persistence | Detectable antibodies at 12+ months |
| Serious adverse events | None related to the vaccine |

Immunogenicity Data

• Seroconversion rate: 94% of vaccinated subjects developed anti-alpha-synuclein IgG antibodies
• Antibody titers: Dose-dependent response observed
• IgG subclass: Predominantly IgG1 and IgG4 subclasses
• Affinity: High-affinity antibodies capable of recognizing oligomeric forms

Long-term Extension Study

An extension study is ongoing to evaluate[^1][^2][^3][^4]:

• Duration: Up to 3 years of follow-up
• Objectives: Long-term safety and antibody durability
• Clinical outcomes: Motor and non-motor symptom progression
• Booster response: Memory antibody response to booster doses

Pharmacokinetics and Pharmacodynamics

Administration

• Route: Intramuscular injection
• Formulation: Peptide adjuvanted with Alum or alternative adjuvant
• Dosing schedule:
• Primary series: 3-4 priming doses at weeks 0, 4, 8
• Boosters: Every 6-12 months to maintain titers

Antibody Kinetics

• Onset: Antibodies detectable by week 4-8
• Peak: Maximum titers achieved 4-8 weeks after final priming dose
• Duration: Antibody levels maintained with periodic boosters
• Memory response: Booster doses induce rapid anamnestic response

Peripheral Sink Hypothesis

A key mechanism by which anti-alpha-synuclein antibodies may benefit [Parkinson's disease](/diseases/parkinsons-disease) patients involves the peripheral sink effect[^5][^6][^7]:

Safety Profile

Adverse Events

UB-312 has shown a favorable safety profile in clinical trials:

| System | Common Events | Frequency |
|--------|-------------|-----------|
| Local | Injection site pain/erythema | Mild, transient |
| Systemic | Fatigue, headache | Common |
| Constitutional | Flu-like symptoms | Transient |
| Immune | No autoimmune encephalitis | Not observed |
| CNS | No ARIA-like events | Not observed |

Safety Advantages Over Passive Immunization

One potential advantage of active vaccination over monoclonal antibody approaches[^8][^9][^10]:

• No ARIA risk: Unlike anti-amyloid antibodies, no amyloid-related imaging abnormalities observed
• Chronic dosing: Can be administered less frequently than IV antibodies
• Cost: Lower manufacturing costs enable broader access

Comparison to Other Alpha-Synuclein Approaches

Other Immunotherapeutic Agents in Development

| Agent | Company | Approach | Status |
|-------|---------|----------|--------|
| UB-312 | Vaxxinity | Active vaccine | Phase 1 |
| PRX002 | Prothelia/Roche | Passive antibody | Phase 1/2 |
| BIIB054 | Biogen | Passive antibody | Phase 2 |
| Lu AF82422 | Lundbeck | Passive antibody | Phase 1 |

Strategic Positioning

UB-312 represents a differentiated approach[^9][^10][^11]:

Current Status and Future Directions

As of 2026, UB-312 remains in Phase 1 development with ongoing extension studies. Vaxxinity has been evaluating options for advancing the program, including potential Phase 2 trial designs and partnership opportunities.

Challenges and Considerations

The alpha-synuclein immunotherapy field has faced challenges[^8][^9][^10]:

• Clinical trial design: Validating PD progression biomarkers
• Patient selection: Identifying appropriate patient populations
• Endpoint selection: Relating biomarker changes to clinical outcomes
• Combination therapy: Potential for combination with dopaminergic treatments

Future Development Path

Potential next steps for UB-312 include:

Regulatory Considerations

Fast Track Designation

Alpha-synuclein-targeting immunotherapies have received regulatory attention:

• FDA Fast Track: For disease-modifying PD therapies
• EMA PRIME: European priority medicines designation
• Breakthrough Therapy: For programs with substantial preclinical support

References

See Also

• [Parkinson's Disease](/diseases/parkinsons-disease)
• [Alpha-Synuclein](/proteins/alpha-synuclein)
• [Alpha-Synuclein Prion-Like Spreading](/mechanisms/alpha-synuclein-prion-like-spreading)
• [Synucleinopathies](/mechanisms/synucleinopathy)
• [Dementia with Lewy Bodies](/diseases/dementia-lewy-bodies)
• [Multiple System Atrophy](/diseases/multiple-system-atrophy)
• [Therapeutic Targetability Rankings](/mechanisms/therapeutic-targetability-rankings)

External Links

• [ClinicalTrials.gov](https://clinicaltrials.gov/)
• [Vaxxinity](https://www.vaxxinity.com/)
• [Michael J. Fox Foundation](https://www.michaeljfox.org/)
• [Parkinson's Progression Markers Initiative](https://www.ppmi-info.org/)

[^2]: [Schrots et al., Design and synthesis of alpha-synuclein peptide vaccines](https://pubmed.ncbi.nlm.nih.gov/34897854/)

[^3]: [Oourke et al., Strain-specific features of alpha-synuclein inclusions](https://pubmed.ncbi.nlm.nih.gov/26450512/)

[^4]: [Chu et al., Alpha-synuclein pathology in Parkinson's disease](https://pubmed.ncbi.nlm.nih.gov/31141339/)

[^5]: [Masliah et al., Passive immunomodulation with antibodies](https://pubmed.ncbi.nlm.nih.gov/21296672/)

[^6]: [Westhoff et al., Immunogenicity of alpha-synuclein peptide vaccines](https://pubmed.ncbi.nlm.nih.gov/32178912/)

[^7]: [Bjorklund et al., Promises and challenges of immunotherapies](https://pubmed.ncbi.nlm.nih.gov/32891423/)

[^8]: [Bhatia et al., Update on alpha-synuclein immunotherapy](https://pubmed.ncbi.nlm.nih.gov/34160278/)

[^9]: [Foltynie et al., Alpha-synuclein therapeutics in clinical trials](https://pubmed.ncbi.nlm.nih.gov/35623376/)

[^10]: [Weihofen et al., Structure-based design of alpha-synuclein vaccines](https://pubmed.ncbi.nlm.nih.gov/32123197/)