TABLE 1.

Immunization

Agent	Sponsor	Type of Therapy	Phase of Development	Clinical Trial Identifier	Status/Findings
Active immunization
AFFITOPE PD01A, (AFF008 Series of studies)	Affiris	Specific active immunotherapy (a synthetic peptide)	Phase 1	2011–002650–31, 2013–001774–20, 2014–002489–54, and 2015–004854–16 (EuraCT numbers)	Measurable humoral antibody response Reduced CSF oligomeric α-Syn; adequate safety and tolerability (Volc et al., 2020)
				NCT02270489 for patients with MSA	Measurable immune response; adequate safety and tolerability (Meissner et al., 2020)
				NCT02618941; NCT01885494; NCT02216188; NCT01568099	Completed, results pending
				NCT02758730	Withdrawn
PD03A (AFF011)	Affiris	Specific active immunotherapy (a synthetic peptide)	Phase 1	NCT02270489 for patients with MSA	Measurable immune response; adequate safety and tolerability (Meissner et al., 2020)
				NCT02267434	Completed, results pending
UB-312	United Neuroscience Ltd.	Synthetic peptide vaccine	Phase 1	NCT04075318	Active, not recruiting
Passive immunization
Prasinezumab (RO7046015/PRX002)	Hoffmann-La Roche-Prothena	Humanized IgG1 monoclonal antibody	Phase 1b	NCT02095171	Adequate safety and tolerability; lowering of free α-Syn in the serum (Schenk et al., 2017)
			NCT02157714	CSF-serum ratio 0.3% (Jankovic et al., 2018)
			Phase 2	NCT03100149	Active not recruiting
				NCT04777331	Recruiting
BIIB054 (Cinpanemab)	Biogen	Human IgG1 monoclonal antibody	Phase 1	NCT03716570	CSF-serum ratio ranged from 0.13% to 0.56% (Brys et al., 2019)
			Phase 2	NCT03318523	Missed primary and secondary endpoints
MEDI1341	Takeda/AstraZeneca	Monoclonal antibody	Phase 1	NCT03272165 NCT04449484	Recruiting
Lu AF82422	H. Lundbeck A/S	Monoclonal antibody	Phase 1	NCT03611569	Recruiting
ABBV-0805	AbbVie	Monoclonal antibody	Phase 1	NCT04127695	Withdrawn
ATV: α-Syn	Denali	Antibody	Preclinical
	AC Immune	Antibody	Preclinical