Compositions and methods for treating alpha-synucleinopathies

Abstract

The present invention provides a method for treating or preventing an alpha-synucleinopathic disease in a subject in need thereof, comprising administering to the subject a fixed dose of 50 to 5,000 mg of an anti-alpha-synuclein antibody or antigen-binding fragment thereof. Corresponding compositions and kits are also provided. In one example, the antibody can be aslo0452ngl-3.

Description

[Technical Field]

[0001] The present invention relates to alpha-synuclein antibodies and their use in the prevention or treatment of diseases, particularly alpha-synucleinopathies, more particularly Parkinson's disease (PD) and Multiple System Atrophy (MSA). [Background technology]

[0002] Alpha-synucleinopathies (or α-synucleinopathies), also known as Lewy body diseases (LBD), are a family of neurodegenerative diseases that all have alpha-synuclein at their core as a key pathological feature (Jellinger (2003) Mov. Disord. 18 Suppl 6:S2-12, and Spillantini and Goedert (2000) Ann. NY Acad. Sci. 920:16-27, both of which are incorporated herein by reference). Alpha-synucleinopathies include Parkinson's disease (PD), dementia with Lewy bodies (DLB), and multiple system atrophy (MSA).

[0003] PD is a slowly progressive, age-related movement disorder that affects more than 1% of people over the age of 65. The hallmark motor symptoms of PD include resting tremor, impaired postural control, bradykinesia, and rigidity. However, PD is also associated with non-motor symptoms, including anosmia, cognitive impairment, sleep-wake dysregulation, autonomic neuropathy, depression, and constipation. PD is defined by the selective loss of dopaminergic neurons and the widespread accumulation of α-synuclein-containing aggregates, called Lewy bodies, in surviving neurons. PD is the second most common neurodegenerative condition after Alzheimer's disease.

[0004] MSA is a rare, but universally fatal, progressive neurodegenerative disorder clinically defined by features of parkinsonism, cerebellar dysfunction, and autonomic dysfunction. Isolated autonomic dysfunction with prominent urogenital dysfunction and orthostatic hypotension, as well as REM sleep behavior disorder, are common features in the early stages of MSA. Similar to PD, MSA is characterized by widespread accumulation of α-synuclein aggregates. No disease-modifying therapy is currently available to halt or slow the progression of MSA.

[0005] The defining and prominent pathology of alpha-synucleinopathies is Lewy bodies and Lewy neurites, which are insoluble inclusions of aggregated protein found within brain neurons after postmortem histopathological examination. The presence of Lewy pathology and neuronal loss in non-motor brain regions, such as the basal forebrain, mesencephalon, amygdala, neocortex, dorsal motor nucleus of the vagus nerve, olfactory bulb, locus coeruleus, and brainstem, can lead to cognitive impairment and dementia, hyposmia, sleep disorders including rapid eye movement sleep behavior disorder (RBD), mood disorders including depression and anxiety, autonomic dysfunction including cardiovascular and gastrointestinal problems (e.g., constipation), and fatigue and somnolence. Some of these non-motor symptoms appear to characterize the premotor or prodromal phase of Parkinson's disease (Kalia et al., Lancet (2015), 386(9996):896-912, incorporated herein by reference).

[0006] The presence of Lewy pathology and neuronal loss in motor brain regions, including most notably the death of dopaminergic neurons in the substantia nigra, can lead to the resting tremor, rigidity, bradykinesia, and impaired postural control that are characteristic of Parkinson's disease (Spillantini and Goedert, Ann NY Acad Sci (2000), 920:16-27, incorporated herein by reference).

[0007] Alpha-synuclein (also called "α-synuclein" or "α-syn") protein is the major structural component of Lewy bodies and Lewy neurites. Alpha-synuclein is a small, acidic protein composed of 140 amino acids (14 kDa). Human native wild-type alpha-synuclein has the amino acid sequence SEQ ID NO: 1, as set forth in UniProtKB accession number P37840. Unless otherwise clear from the context, reference to alpha-synuclein or a fragment thereof includes the above native human wild-type amino acid sequence and its human allelic variants, particularly those associated with Lewy body disease (e.g., E46K, A30P, H50Q, G51D, and A53T, where the first letter indicates the amino acid in SEQ ID NO: 1, the number is the codon position in SEQ ID NO: 1, and the second letter is the amino acid in the allelic variant). Such variants may optionally be present individually or in any combination. The induced mutations E83Q, A90V, A76T, which enhance alpha-synuclein aggregation, can also occur individually or in combination with each other and / or the human allelic variants E46K, A30P, H50Q, G51D, and A53T. At the structural level, alpha-synuclein comprises three distinct regions: an amphipathic N-terminal alpha-helical domain (residues 1-60) with lipid and membrane-binding properties, a central hydrophobic amyloid-binding domain (residues 61-95) that encodes the non-amyloid-beta component (NAC) of plaques, and an acidic proline-rich C-terminal tail (residues 96-140). Residues 71-82 of the NAC domain are thought to be key to the aggregation / fibrillation properties of alpha-synuclein by enabling the protein to switch from a random coil to a beta-sheet conformation (Bisaglia et al. (2009) FASEB J. 23(2):329-40, incorporated herein by reference). The C-terminal domain does not contain significant secondary structure but does contain a critical phosphorylation site at residue Ser129 and multiple tyrosine residues that are nitrated in cytosolic alpha-synuclein inclusions. N- and C-terminal truncated forms of alpha-synuclein also exist.Post-translational modifications to the protein can affect alpha-synuclein aggregation and toxicity (Oueslati et al. (2010) Prog. Brain. Res. 183:115-45, incorporated herein by reference).

[0008] Under pathological conditions, abnormal alpha-synuclein aggregation may be key to the pathological changes seen in alpha-synucleinopathies (Lashuel et al. (2002) Nature 418:291 and Tsigelny et al. (2007) FEBS J. 274:1862-1877, both of which are incorporated herein by reference). In vitro studies have shown that alpha-synuclein monomers may form the starting point of the aggregation process. Monomers can aggregate into various small oligomeric species, which are then stabilized by beta-sheet interactions to form protofibrils that can subsequently polymerize into insoluble fibril structures reminiscent of those identified in Lewy bodies (Cremades et al. (2012) Cell (2012), 149(5):1048-59, incorporated herein by reference). In vitro and in vivo studies indicate that the neurotoxic effects of alpha-synuclein appear to be induced by small soluble oligomeric conformers or protofibrils (Winner et al. (2011) Proc. Natl. Acad. Sci. USA 108(10):4194-9 and Danzer et al. (2007) J. Neurosci. 27(34):9220-32, both of which are incorporated herein by reference). While fibrillar aggregates of alpha-synuclein are a hallmark of PD, oligomeric forms of alpha-synuclein are the toxic species (Danzer et al. (2007) J. Neurosci. 27(34):9220-32, Lashuel et al. (2002) Nature 418:291, and Winner et al. (2011) Proc. Natl. Acad. Sci. USA 108:4194-4199, each of which is incorporated herein by reference).

[0009] Alpha-synuclein oligomers can be released into the extracellular environment and taken up by neighboring cells in a "propagation" mechanism (Angot and Brundin, (2009) Parkinsonism Relat. Disord. 15 Suppl 3:S143-147; Desplats et al. (2009) Proc. Natl. Acad. Sci. USA 106:13010-13015; and Lee et al. (2010) J. Biol. Chem. 285:9262-9272, each of which is incorporated herein by reference). Alpha-synuclein aggregates can propagate misfolding via a prion-like spreading mechanism (Lee et al. (2010) Nat. Rev. Neurol. 6:702-706, Luk et al. (2012) J. Exp. Med. 209(5):975-86, and Luk et al. (2012) Science 338(6109):949-53, each of which is incorporated herein by reference). Thus, alpha-synuclein can induce neurodegeneration either by oligomeric toxicity or propagation and prion-like spreading.

[0010] It is now well established and accepted that under conditions of cellular stress and through this release of alpha-synuclein into the extracellular environment, pathological transmissible forms of alpha-synuclein can be propagated between neurons (Recasens and Dehay, Front Neuroanat (2014), 8:159, incorporated herein by reference).

[0011] Approaches to treating alpha-synucleinopathies have relied on passive immunotherapy. Passive immunotherapy using antibodies targeting alpha-synuclein has been tested in many preclinical alpha-synucleinopathic mouse models (Lawand et al. (2015) Expert Opin. Ther. Targets 19:1-10, incorporated herein by reference). Specifically, studies using a monoclonal antibody against alpha-synuclein (9E4) have shown in vivo clearance of alpha-synuclein aggregates and pathology, behavioral improvement, and neuroprotective effects (WO 2014 / 058924, incorporated herein by reference).

[0012] Further studies using passive immunization of alpha-synuclein transgenic mice, developed as an experimental model of PD / DLB, showed that the 9E4 monoclonal antibody eliminated alpha-synuclein pathology, reduced synaptic and axonal defects, prevented the loss of striatal tyrosine hydroxylase fibers, and significantly reduced memory and motor dysfunction (Games et al. (2014) J. Neurosci. 34(28):9441-54, Bae et al. (2012) J. Neurosci. 32(39):13454-69, and Masliah et al. (2011) PLoS One 6(4):e19338, each of which is incorporated herein by reference). Furthermore, passive administration of anti-alpha-synuclein monoclonal antibodies in wild-type mice injected intrastriatally with synthetic alpha-synuclein preformed fibrils (pff) resulted in robust reduction of Lewy pathology, prevention of dopamine neuron loss in the substantia nigra, and significant improvement of motor deficits manifested in a mouse model after pff treatment (Tran et al. (2014) Cell Rep. 7(6):2054-65, incorporated herein by reference).

[0013] However, no passive immunotherapy approaches have yet been approved for PD and other α-synucleinopathies, and therefore current approaches to these diseases primarily focus on treating the movement-related symptoms of the disease.

[0014] Thus, there is a need in the art for therapies to treat alpha-synucleinopathies, particularly in humans. Summary of the Invention

[0015] The present invention relates to anti-α-synuclein antibodies or antigen-binding fragments thereof. The present invention relates to the treatment or prevention of α-synucleinopathies using such antibodies or antibody fragments. In particular, the present invention relates to specific dosing regimens that can be used when anti-α-synuclein antibodies or antigen-binding fragments thereof are administered to treat or prevent α-synucleinopathies. More specifically, the present invention relates to treatment of α-synucleinopathies comprising administering to a subject a fixed dose, e.g., a dose that is independent of the subject's body weight, of an anti-α-synuclein antibody or antigen-binding fragment thereof.

[0016] Accordingly, the present invention provides a method for treating or preventing an α-synucleinopathy in a subject in need thereof, the method comprising administering to the subject a fixed dose of 50 to 5,000 mg of an anti-α-synuclein antibody or antigen-binding fragment thereof. The present invention also provides an anti-α-synuclein antibody or antigen-binding fragment thereof for use in a method for treating or preventing an α-synucleinopathy in a subject, the method comprising administering to the subject a fixed dose of 50 to 5,000 mg of the anti-α-synuclein antibody or antigen-binding fragment thereof. The present invention also provides use of an anti-α-synuclein antibody or antigen-binding fragment thereof in the manufacture of a medicament for treating or preventing an α-synucleinopathy in a subject, the medicament comprising a fixed dose of 50 to 5,000 mg of the antibody or antigen-binding fragment thereof, or the treatment or prevention comprising administering a fixed dose of 50 to 5,000 mg of the antibody or antigen-binding fragment thereof. The present invention also provides a composition comprising a fixed dose of 50 to 5,000 mg of an anti-α-synuclein antibody or antigen-binding fragment thereof for use in a method for treating or preventing α-synucleinopathies.The present invention also provides a kit comprising an anti-α-synuclein antibody or antigen-binding fragment thereof and instructions for use thereof for treating α-synucleinopathies at a fixed dose of 50 to 5,000 mg.

[0017] The fixed dose of the anti-α-synuclein antibody or antigen-binding fragment thereof may be 70 to 4,500 mg. The fixed dose of the anti-α-synuclein antibody or antigen-binding fragment thereof may be 1,000 to 4,500 mg. The fixed dose of the anti-α-synuclein antibody or antigen-binding fragment thereof may be 1,800 to 2,600 mg. The fixed dose of the anti-α-synuclein antibody or antigen-binding fragment thereof may be 2,000 to 2,400 mg. The fixed dose of the anti-α-synuclein antibody or antigen-binding fragment thereof may be up to 2,600 mg. The fixed dose of the anti-α-synuclein antibody or antigen-binding fragment thereof may be up to 2,400 mg. The fixed dose of the anti-α-synuclein antibody or antigen-binding fragment thereof may be up to 2,200 mg. The fixed dose of the anti-α-synuclein antibody or antigen-binding fragment thereof may be up to 2,000 mg. The fixed dose of the anti-alpha-synuclein antibody or antigen-binding fragment thereof may be 1,400 mg. The fixed dose of the anti-alpha-synuclein antibody or antigen-binding fragment thereof may be 1,600 mg. The fixed dose of the anti-alpha-synuclein antibody or antigen-binding fragment thereof may be 1,700 mg. The fixed dose of the anti-alpha-synuclein antibody or antigen-binding fragment thereof may be 1,800 mg. The fixed dose of the anti-alpha-synuclein antibody or antigen-binding fragment thereof may be 2,000 mg or 2,400 mg. The fixed dose of the anti-alpha-synuclein antibody or antigen-binding fragment thereof may be 2,000 mg. The fixed dose of the anti-alpha-synuclein antibody or antigen-binding fragment thereof may be 2,400 mg. The fixed dose of the anti-alpha-synuclein antibody or antigen-binding fragment thereof may be 4,500 mg.

[0018] The method may include administering the anti-alpha-synuclein antibody or antigen-binding fragment thereof intravenously, subcutaneously, intradermally, or intramuscularly. Preferably, the method may include administering the anti-alpha-synuclein antibody or antigen-binding fragment thereof intravenously.

[0019] The anti-α-synuclein antibody or antigen-binding fragment thereof may be administered to a subject once every 3 to 5 weeks. The anti-α-synuclein antibody or antigen-binding fragment thereof may be administered to a subject multiple times over a period of at least 3 months, 6 months, 9 months, 1 year, 2 years, or 5 years. The anti-α-synuclein antibody or antigen-binding fragment thereof may be administered to a subject once every 4 weeks over a period of at least 3 months, 6 months, 9 months, 1 year, 2 years, or 5 years.

[0020] The α-synucleinopathy may be selected from Parkinson's disease (PD), dementia with Lewy bodies (DLB), multiple system atrophy (MSA), Alzheimer's disease, pure autonomic failure, REM behavior disorder, prodromal synucleinopathy, and neuroaxonal dystrophy. The α-synucleinopathy may be Parkinson's disease (PD). The α-synucleinopathy may be multiple system atrophy (MSA). The α-synucleinopathy may be dementia with Lewy bodies (DLB). The subject may have been diagnosed with possible or probable MSA. The subject to be treated may have a Unified Multiple System Atrophy Rating Scale (UMSARS) Part I score of 21 or less. A treated subject may have a swallowing severity score of 2 or less, a walking severity score of 2 or less, and / or a falls severity score of 2 or less, as measured using the Unified Multiple System Atrophy Rating Scale (UMSARS) Part I score. A treated subject may have a UMSARS Part IV disability score of 3 or less.

[0021] The method may reduce the progression of α-synucleinopathy as measured by the subject's score on a modified version of UMSARS Part I. The method may reduce the progression of α-synucleinopathy as measured by the subject's UMSARS total score. The method may reduce the progression of α-synucleinopathy as measured by the subject's UMSARS Part I score. The method may reduce the progression of α-synucleinopathy as measured by the subject's UMSARS Part II score. The method may reduce the progression of α-synucleinopathy as measured by the subject's 11-item UMSARS score. The method may reduce the progression of α-synucleinopathy as measured by the subject's Clinical Global Impression-Severity (CGI-S) scale score.

[0022] The method may reduce the progression of alpha-synucleinopathies as measured by alpha-synuclein diffusion in the subject. The method may reduce the progression of alpha-synucleinopathies as measured by free, unbound alpha-synuclein levels in the subject's cerebrospinal fluid (CSF).

[0023] The method may reduce a subject's score on a modified version of the Unified Multiple System Atrophy Rating Scale (UMSARS) Part I. The method may reduce a subject's Unified Multiple System Atrophy Rating Scale (UMSARS) Part I score. The method may reduce a subject's Unified Multiple System Atrophy Rating Scale (UMSARS) Part II score. The method may reduce a subject's 11-item Unified Multiple System Atrophy Rating Scale (UMSARS) score. The method may reduce a subject's Clinical Global Impression-Severity (CGI-S) scale score.

[0024] The method may reduce alpha-synuclein diffusion in a subject. The method may reduce free, unbound alpha-synuclein levels in cerebrospinal fluid (CSF) of a subject.

[0025] The anti-α-synuclein antibody or antigen-binding fragment thereof may bind to free, unbound α-synuclein in the CSF of a subject. The anti-α-synuclein antibody or antigen-binding fragment thereof may bind to monomeric and / or oligomeric α-synuclein in the CSF of a subject. The anti-α-synuclein antibody or antigen-binding fragment thereof may bind to α-synuclein in the CSF of a subject in vivo.

[0026] The anti-α-synuclein antibody or antigen-binding fragment thereof may specifically bind to a region encompassed by approximately amino acid 102 to approximately amino acid 130 within the C-terminal region of human α-synuclein. The anti-α-synuclein antibody or antigen-binding fragment thereof may bind to both monomeric and aggregated forms of α-synuclein. The anti-α-synuclein antibody or antigen-binding fragment thereof may bind to both monomeric and aggregated forms of α-synuclein in vivo. The anti-α-synuclein antibody or antigen-binding fragment thereof may sequester both monomeric and aggregated forms of α-synuclein. The anti-α-synuclein antibody or antigen-binding fragment thereof may sequester both monomeric and aggregated forms of α-synuclein in vivo.

[0027] The anti-alpha-synuclein antibody or antigen-binding fragment thereof has a K of less than 500 pM. D It can bind to monomeric human α-synuclein at 1000 kJ / s.

[0028] Anti-alpha-synuclein antibodies or antigen-binding fragments thereof can reduce alpha-synuclein diffusion in vivo.

[0029] The anti-alpha-synuclein antibody or antigen-binding fragment thereof may comprise three heavy chain CDRs having the sequences of H-CDR1 of SEQ ID NO: 5, H-CDR2 of SEQ ID NO: 15, and H-CDR3 of SEQ ID NO: 16, and three light chain CDRs having the sequences of L-CDR1 of SEQ ID NO: 20, L-CDR2 of SEQ ID NO: 10, and L-CDR3 of SEQ ID NO: 21.

[0030] The anti-α-synuclein antibody or antigen-binding fragment thereof may comprise a variable heavy chain region comprising an amino acid sequence at least 90% identical to the amino acid sequence of SEQ ID NO: 14. The anti-α-synuclein antibody or antigen-binding fragment thereof may comprise a variable heavy chain region comprising an amino acid sequence at least 90% identical to the amino acid sequence of SEQ ID NO: 14. The anti-α-synuclein antibody or antigen-binding fragment thereof may comprise a variable light chain region comprising an amino acid sequence at least 90% identical to the amino acid sequence of SEQ ID NO: 19. The anti-α-synuclein antibody or antigen-binding fragment thereof may comprise a variable heavy chain region comprising an amino acid sequence at least 95% identical to the amino acid sequence of SEQ ID NO: 14, and a variable light chain region comprising an amino acid sequence at least 95% identical to the amino acid sequence of SEQ ID NO: 19. The anti-alpha-synuclein antibody, or antigen-binding fragment thereof, may comprise a variable heavy chain region comprising the amino acid sequence of SEQ ID NO:14 and a variable light chain region comprising the amino acid sequence of SEQ ID NO:19.

[0031] The anti-alpha-synuclein antibody or antigen-binding fragment thereof may comprise a heavy chain comprising an amino acid sequence at least 90% identical to the amino acid sequence of SEQ ID NO: 12 or SEQ ID NO: 62. The anti-alpha-synuclein antibody or antigen-binding fragment thereof may comprise a heavy chain comprising an amino acid sequence at least 90% identical to the amino acid sequence of SEQ ID NO: 12 or SEQ ID NO: 62. The anti-alpha-synuclein antibody or antigen-binding fragment thereof may comprise a light chain comprising an amino acid sequence at least 90% identical to the amino acid sequence of SEQ ID NO: 17. The anti-alpha-synuclein antibody or antigen-binding fragment thereof may comprise a heavy chain comprising an amino acid sequence at least 95% identical to the amino acid sequence of SEQ ID NO: 12 or SEQ ID NO: 62, and a light chain comprising an amino acid sequence at least 95% identical to the amino acid sequence of SEQ ID NO: 17. The anti-alpha-synuclein antibody or antigen-binding fragment thereof may comprise a heavy chain comprising the amino acid sequence of SEQ ID NO:12 or SEQ ID NO:62 and a light chain comprising the amino acid sequence of SEQ ID NO:17.

[0032] The anti-alpha-synuclein antibody or antigen-binding fragment thereof may be an antibody.

[0033] The anti-alpha-synuclein antibody or antigen-binding fragment thereof may comprise a triple mutation in the Fc region corresponding to L234F / L235E / P331S numbered according to Kabat numbering. [Brief explanation of the drawings]

[0034] These and other features of the present invention will become more apparent in the following detailed description taken in conjunction with the accompanying drawings. [Figure 1] Figure 1 shows a simplified layout of a double-blind, placebo-controlled study of aslo0452ngl-3 at single ascending doses (SAD) up to 4,500 mg in healthy subjects aged 18 to 65 years. [Figure 2] Pharmacokinetic (PK) concentrations of aslo0452ngl-3 observed in a single ascending dose study, stratified by dose level. [Figure 3] Figure 1 shows a simplified layout of a double-blind, placebo-controlled study of aslo0452ngl-3 at multiple ascending doses (MADs) up to 4,200 mg in subjects aged 40 to 85 years with Parkinson's disease. [Figure 4] Pharmacokinetic (PK) concentrations of aslo0452ngl-3 observed in a multiple ascending dose study stratified by dose level are shown. [Figure 5] Dose normalized (DN) observed aslo0452 ngl-3 pharmacokinetic (PK) concentrations are shown in single and multiple ascending dose studies.

[0035] [Table 1-1]

[0036] [Table 1-2] DETAILED DESCRIPTION OF THE INVENTION

[0037] 4.1 Treatment and prevention of alpha-synucleinopathies

[0038] Unless otherwise defined herein, scientific and technical terms used in connection with this application shall have the meanings commonly understood by one of ordinary skill in the art to which this disclosure belongs. It is to be understood that the present invention is not limited to the particular methodology, protocols, and reagents, etc., described herein, as such may vary. The terminology used herein is for the purpose of describing particular examples only and is not intended to limit the scope of the present invention, which is defined solely by the claims.

[0039] The present invention provides a method for treating or preventing an α-synucleinopathy in a subject in need thereof, the method comprising administering to the subject a fixed dose of 50 to 5,000 mg of an anti-α-synuclein antibody or antigen-binding fragment thereof. The present invention also provides an anti-α-synuclein antibody or antigen-binding fragment thereof for use in a method for treating or preventing an α-synucleinopathy in a subject, the method comprising administering to the subject a fixed dose of 50 to 5,000 mg of the anti-α-synuclein antibody or antigen-binding fragment thereof. The present invention also provides use of an anti-α-synuclein antibody or antigen-binding fragment thereof in the manufacture of a medicament for treating or preventing an α-synucleinopathy in a subject, the medicament comprising a fixed dose of 50 to 5,000 mg of the antibody or antigen-binding fragment thereof, or the treatment or prevention comprising administering a fixed dose of 50 to 5,000 mg of the antibody or antigen-binding fragment thereof. Reference herein to the methods of the invention is also intended to encompass equivalent uses of the invention, or antibodies of antigen-binding fragments thereof for use in the invention, or compositions comprising such antibodies of antigen-binding fragments thereof for use in the invention. Thus, where the invention relates to an anti-α-synuclein antibody or antigen-binding fragment thereof for use in a method of treating or preventing α-synucleinopathies, or the use of an anti-α-synuclein antibody or antigen-binding fragment thereof in the manufacture of a medicament for treating or preventing α-synucleinopathies, the method of treating or preventing α-synucleinopathies can be any method of treating or preventing α-synucleinopathies as described herein. Also provided are kits comprising (a) an anti-α-synuclein antibody or antigen-binding fragment thereof and (b) instructions for its use to treat α-synucleinopathies at a fixed dose of 50 to 5,000 mg. The antibody or antigen-binding fragment thereof in the methods of the invention, the antibody or antigen-binding fragment thereof for use in the invention, and the uses, compositions, or kits of the invention can be any antibody or antigen-binding fragment thereof as described herein.

[0040] Preferably, the dose disclosed herein is a fixed dose.As used herein, the term "fixed dose" refers to a dose that is used for all subjects, for example, the dose is an amount that does not vary based on the subject's body weight.A fixed dose may also be a specific, invariant amount, and the same dose is used for all subjects, or for all adult subjects, such as the unit dosage form disclosed herein.A fixed dose is typically expressed in terms of the amount of active agent, such as an antibody or its antigen-binding fragment, rather than the amount expressed in terms of the body weight or mass of the subject to be treated.

[0041] As used herein, the term "treating" or "treatment" refers to the improvement of a disease or disorder, or at least one discernible symptom thereof. "Treatment" or "treating" may refer to the improvement of at least one measurable physical parameter, not necessarily discernible by the patient. "Treatment" or "treating" may refer to inhibiting, reducing, or slowing the progression of a disease or disorder, either physically (e.g., stabilization of discernible symptoms), physiologically (e.g., stabilization of physical parameters), or both. For example, "treating" or "treatment" may refer to reducing the progression of an α-synucleinopathy in a subject compared to the progression expected for a subject with that α-synucleinopathy, or compared to the progression expected in a subject at that stage of the α-synucleinopathy. "Treatment" or "treating" may refer to delaying the onset of a disease or disorder.

[0042] As used herein, the term "preventing" or "prevention" refers to a reduction in the risk of acquiring a given disease or disorder. "Preventing" or "prevention" can refer to preventing or delaying the onset of one or more symptoms of a disease or disorder, for example, compared to an untreated control or placebo.

[0043] "Subject" refers to an animal, such as a mammal, that has been or is the object of treatment, observation, or experiment. The methods described herein may be useful for both human therapy and veterinary applications. Preferably, the subject is a human. The subject to be treated may be an adult human. The subject may be human and may be at least 30 years old, at least 40 years old, at least 50 years old, at least 60 years old, at least 70 years old, or at least 75 years old. The subject may be at least 40 years old. The subject may be 50-60 years old.

[0044] Subjects to be treated must have a blood glucose level of at least 15 kg / m at baseline. 2 The subject may be a human with a BMI of at least 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, or 40 kg / m at baseline. 2 The subject may be a human with a BMI of 50 kg / m at baseline. 2 The subject may be a human with a BMI of 50, 49, 48, 47, 46, 45, 44, 43, 42, 41, or 40 kg / m at baseline. 2 The subject may have a BMI of 15 to 40 kg / m at baseline. 2 Preferably, the subject has a BMI of 18 to 35 kg / m at baseline. 2 The subject is a person having a BMI of 0.05.

[0045] The methods, uses, compositions, and kits of the invention utilize a dose (e.g., a fixed dose) of 50 to 5,000 mg of an anti-α-synuclein antibody or antigen-binding fragment thereof, and, for example, involve administering such a (fixed) dose to a subject. The (fixed) dose of 50 to 5,000 mg can be at least 50 mg, e.g., at least 70 mg, at least 100 mg, at least 250 mg, at least 500 mg, at least 750 mg, at least 1,000 mg, at least 1,250 mg, at least 1,500 mg, at least 1,750 mg, at least 2,000 mg, at least 2,250 mg, at least 2,500 mg, at least 2,750 mg, at least 3,000 mg, at least 3,250 mg, at least 3,500 mg, at least 3,750 mg, at least 4,000 mg, at least 4,250 mg, at least 4,500 mg, or at least 4,750 mg. The 50-5,000 mg (fixed) dose can be up to 5,000 mg, e.g., up to 4,750 mg, up to 4,500 mg, up to 4,250 mg, up to 4,000 mg, up to 3,750 mg, up to 3,500 mg, up to 3,250 mg, up to 3,000 mg, up to 2,750 mg, up to 2,500 mg, up to 2,250 mg, up to 2,000 mg, up to 1,750 mg, up to 1,500 mg, up to 1,250 mg, up to 1,000 mg, up to 750 mg, up to 500 mg, up to 250 mg, up to 100 mg, or up to 70 mg. Any of these upper and lower endpoints can be combined within the 50-5,000 mg range. For example, the anti-α-synuclein antibody or antigen-binding fragment thereof can be administered to a subject at a dose of 70 to 4,500 mg, 1,000 to 4,500 mg, 1,500 to 4,500 mg, 1,800 to 2,600 mg, 2,000 to 2,600 mg, or 2,000 to 2,400 mg, e.g., a fixed dose.

[0046] The anti-α-synuclein antibody or antigen-binding fragment thereof may be administered to a subject at a dose of up to 2,600 mg, e.g., a fixed dose. For example, the anti-α-synuclein antibody or antigen-binding fragment thereof may be administered to a subject at a dose of 70 to 2,600 mg, 1,000 to 2,600 mg, 1,500 to 2,600 mg, 1,800 to 2,600 mg, or 2,000 to 2,600 mg, e.g., a fixed dose.

[0047] The anti-α-synuclein antibody or antigen-binding fragment thereof may be administered to a subject at a dose of up to 2,400 mg, e.g., a fixed dose. For example, the anti-α-synuclein antibody or antigen-binding fragment thereof may be administered to a subject at a dose of 70 to 2,400 mg, 1,000 to 2,400 mg, 1,500 to 2,400 mg, 1,800 to 2,400 mg, or 2,000 to 2,400 mg, e.g., a fixed dose.

[0048] The anti-α-synuclein antibody or antigen-binding fragment thereof may be administered to a subject at a dose of up to 2,200 mg, e.g., a fixed dose. For example, the anti-α-synuclein antibody or antigen-binding fragment thereof may be administered to a subject at a dose of 70 to 2,200 mg, 1,000 to 2,200 mg, 1,500 to 2,200 mg, 1,800 to 2,200 mg, or 2,000 to 2,200 mg, e.g., a fixed dose.

[0049] The anti-α-synuclein antibody or antigen-binding fragment thereof may be administered to a subject at a dose of up to 2,000 mg, e.g., a fixed dose. For example, the anti-α-synuclein antibody or antigen-binding fragment thereof may be administered to a subject at a dose of 70 to 2,000 mg, 1,000 to 2,000 mg, 1,500 to 2,000 mg, or 1,800 to 2,000 mg, e.g., a fixed dose.

[0050] The anti-alpha-synuclein antibody or antigen-binding fragment thereof can be administered to a subject at a dose, e.g., a fixed dose, of 50, 100, 150, 200, 250, 300, 400, 500, 600, 700, 800, 900, 1,000, 1,200, 1,400, 1,600, 1,800, 2,000, 2,200, 2,400, 2,600, 2,800, 3,000, 3,200, 3,400, 3,600, 3,800, 4,000, 4,250, 4,500, 4,750, or 5,000 mg. The anti-alpha-synuclein antibody or antigen-binding fragment thereof can be administered to a subject at a dose, e.g., a fixed dose, of about 50, about 100, about 150, about 200, about 250, about 300, about 400, about 500, about 600, about 700, about 800, about 900, about 1,000, about 1,200, about 1,400, about 1,600, about 1,800, about 2,000, about 2,200, about 2,400, about 2,600, about 2,800, about 3,000, about 3,200, about 3,400, about 3,600, about 3,800, about 4,000, about 4,250, about 4,500, about 4,750, or about 5,000 mg. The anti-α-synuclein antibody or antigen-binding fragment thereof may be administered to a subject at a dose, e.g., a fixed dose, of about 70, 210, 400, 1,200, 2,000, 2,400, 4,200, or 4,500 mg. Preferably, the anti-α-synuclein antibody or antigen-binding fragment thereof is administered to a subject at a dose, e.g., a fixed dose, e.g., a 1,200 mg dose, of about 1,200 mg. Preferably, the anti-α-synuclein antibody or antigen-binding fragment thereof is administered to a subject at a dose, e.g., a fixed dose, e.g., a 2,000 mg dose, of about 2,000 mg. Preferably, the anti-α-synuclein antibody or antigen-binding fragment thereof is administered to a subject at a dose, e.g., a fixed dose, e.g., a 2,400 mg dose, of about 2,400 mg. Preferably, the anti-alpha-synuclein antibody or antigen-binding fragment thereof is administered to the subject at a dose of about 4,200 mg, e.g., a fixed dose, e.g., a 4,200 mg dose. Preferably, the anti-alpha-synuclein antibody or antigen-binding fragment thereof is administered to the subject at a dose of about 4,500 mg, e.g., a fixed dose, e.g., a 4,500 mg dose.

[0051] The anti-alpha-synuclein antibody or antigen-binding fragment thereof may be administered to a subject at a dose of about 1,400 mg, e.g., a fixed dose, e.g., a 1,400 mg dose. The anti-alpha-synuclein antibody or antigen-binding fragment thereof may be administered to a subject at a dose of about 1,600 mg, e.g., a fixed dose, e.g., a 1,600 mg dose. The anti-alpha-synuclein antibody or antigen-binding fragment thereof may be administered to a subject at a dose of about 1,700 mg, e.g., a fixed dose, e.g., a 1,700 mg dose. The anti-alpha-synuclein antibody or antigen-binding fragment thereof may be administered to a subject at a dose of about 1,800 mg, e.g., a fixed dose, e.g., a 1,800 mg dose.

[0052] Treatment or prevention can be achieved by a single administration or multiple administrations of an anti-alpha-synuclein antibody or antigen-binding fragment thereof. For example, treatment or prevention can include administering two, three, four, five, six, seven, eight, nine, ten, or more than ten doses of an anti-alpha-synuclein antibody or antigen-binding fragment thereof to a subject. Each dose can be a dose, such as a fixed dose, as disclosed herein. Treatment or prevention can include multiple administrations, such as repeated administrations, of an anti-alpha-synuclein antibody or antigen-binding fragment thereof over the course of treatment, as described herein.

[0053] A course of treatment refers to a treatment regimen that includes several rounds of administration as part of a method for treating or preventing alpha-synucleinopathies according to the present invention. A course of treatment can last for one week or more, one month or more, e.g., 2, 3, 4, 5, 6, 7, 8, 9, 10, or 11 months, or one year or more, e.g., one, two, three, four, five, or more years. A course of treatment may continue without a fixed endpoint, e.g., the course of treatment may continue for the lifetime of the subject being treated. Multiple administrations, such as repeat administrations, may be continued at regular or irregular intervals during the course of treatment, as determined by a physician as necessary.

[0054] The anti-α-synuclein antibody or antigen-binding fragment thereof can be administered to a subject daily or less frequently, for example, weekly or monthly. The anti-α-synuclein antibody or antigen-binding fragment thereof can be administered to a subject once a week, twice a week, three times a week, four times a week, five times a week, six times a week, or seven times a week. The anti-α-synuclein antibody or antigen-binding fragment thereof can be administered to a subject once every two weeks, once every three weeks, once every four weeks, once a month, twice a month, three times a month, or four times a month. The anti-alpha-synuclein antibody or antigen-binding fragment thereof may be administered to a subject once per year, twice per year, three times per year, four times per year, five times per year, six times per year, seven times per year, eight times per year, nine times per year, ten times per year, eleven times per year, or twelve times per year.

[0055] The anti-alpha-synuclein antibody or antigen-binding fragment thereof may be administered to a subject multiple times at intervals of 1 week, 2 weeks, 3 weeks, 4 weeks, 1 month, 2 months, 3 months, 6 months, or 1 year. Treatment or prevention may involve administering the anti-alpha-synuclein antibody or antigen-binding fragment thereof to a subject weekly, every 2 weeks, every 3 weeks, every 3 to 5 weeks, every 4 weeks, monthly, every 2 months, every 3 months, every 6 months, or yearly.

[0056] When an anti-α-synuclein antibody or antigen-binding fragment thereof is administered in multiple doses, such as repeated doses, each of the doses may be a fixed dose as described herein. For example, each dose in the methods or uses of the present invention may comprise a fixed dose of 50 to 5,000 mg of an anti-α-synuclein antibody or antigen-binding fragment thereof, as disclosed herein. In such cases, the number of doses or frequency of administration may be any of the options disclosed herein. Multiple doses, such as repeated doses, of an anti-α-synuclein antibody or antigen-binding fragment thereof may each be the same dose. Two or more administrations of an anti-α-synuclein antibody or antigen-binding fragment thereof may each be the same dose. Multiple doses, such as repeated administrations of an anti-α-synuclein antibody or antigen-binding fragment thereof, may each be a dose within the dosage ranges disclosed herein. For example, each administration of an anti-α-synuclein antibody or antigen-binding fragment thereof in the methods or uses of the present invention may be a fixed dose in the range of 70 to 4,500 mg. Each administration of an anti-α-synuclein antibody or antigen-binding fragment thereof in the methods or uses of the present invention may be a fixed dose in the range of 1,000 to 4,500 mg. Each administration of an anti-α-synuclein antibody or antigen-binding fragment thereof in the methods or uses of the present invention may be a fixed dose in the range of 1,800 to 2,600 mg. Each administration of an anti-α-synuclein antibody or antigen-binding fragment thereof in the methods or uses of the present invention may be a fixed dose in the range of 2,000 to 2,400 mg. Each administration of an anti-α-synuclein antibody or antigen-binding fragment thereof in the methods or uses of the present invention may be a fixed dose of approximately 2,000 mg. Each administration of an anti-α-synuclein antibody or antigen-binding fragment thereof in the methods or uses of the present invention may be a fixed dose of approximately 2,400 mg.

[0057] Each administration in the methods or uses of the present invention may comprise a fixed dose of up to 2,600 mg of an anti-α-synuclein antibody or antigen-binding fragment thereof, as disclosed herein. For example, each administration in the methods or uses of the present invention may be a fixed dose ranging from 70 to 2,600 mg. Each administration in the methods or uses of the present invention may be a fixed dose ranging from 1,000 to 2,600 mg. Each administration in the methods or uses of the present invention may be a fixed dose ranging from 1,500 to 2,600 mg. Each administration in the methods or uses of the present invention may be a fixed dose ranging from 2,000 to 2,600 mg.

[0058] Each administration in the methods or uses of the present invention may comprise a fixed dose of up to 2,400 mg of an anti-α-synuclein antibody or antigen-binding fragment thereof, as disclosed herein. For example, each administration in the methods or uses of the present invention may be a fixed dose ranging from 70 to 2,400 mg. Each administration in the methods or uses of the present invention may be a fixed dose ranging from 1,000 to 2,400 mg. Each administration in the methods or uses of the present invention may be a fixed dose ranging from 1,500 to 2,400 mg. Each administration in the methods or uses of the present invention may be a fixed dose ranging from 2,000 to 2,400 mg.

[0059] Each administration in the methods or uses of the present invention may comprise a fixed dose of up to 2,200 mg of an anti-α-synuclein antibody or antigen-binding fragment thereof, as disclosed herein. For example, each administration in the methods or uses of the present invention may be a fixed dose in the range of 70 to 2,200 mg. Each administration in the methods or uses of the present invention may be a fixed dose in the range of 1,000 to 2,200 mg. Each administration in the methods or uses of the present invention may be a fixed dose in the range of 1,500 to 2,200 mg. Each administration in the methods or uses of the present invention may be a fixed dose in the range of 2,000 to 2,200 mg.

[0060] Each administration in the methods or uses of the present invention may comprise a fixed dose of up to 2,000 mg of an anti-α-synuclein antibody or antigen-binding fragment thereof, as disclosed herein. For example, each administration in the methods or uses of the present invention may be a fixed dose in the range of 70 to 2,000 mg. Each administration in the methods or uses of the present invention may be a fixed dose in the range of 1,000 to 2,000 mg. Each administration in the methods or uses of the present invention may be a fixed dose in the range of 1,500 to 2,000 mg.

[0061] Each administration of an anti-alpha-synuclein antibody or antigen-binding fragment thereof in the methods or uses of the present invention may be a fixed dose of about 1,400 mg. Each administration of an anti-alpha-synuclein antibody or antigen-binding fragment thereof in the methods or uses of the present invention may be a fixed dose of about 1,600 mg. Each administration of an anti-alpha-synuclein antibody or antigen-binding fragment thereof in the methods or uses of the present invention may be a fixed dose of about 1,700 mg. Each administration of an anti-alpha-synuclein antibody or antigen-binding fragment thereof in the methods or uses of the present invention may be a fixed dose of about 1,800 mg.

[0062] The anti-alpha-synuclein antibody or antigen-binding fragment thereof may be administered to a subject every four weeks. Thus, the methods or uses of the invention may comprise administering a fixed dose of 2,000, 2,400, or 4,500 mg of an anti-alpha-synuclein antibody or antigen-binding fragment thereof to a subject every four weeks. The method may comprise administering a fixed dose of 2,000 mg of an anti-alpha-synuclein antibody or antigen-binding fragment thereof to a subject every four weeks. The method may comprise administering a fixed dose of 2,400 mg of an anti-alpha-synuclein antibody or antigen-binding fragment thereof to a subject every four weeks. The method may comprise administering a fixed dose of 4,500 mg of an anti-alpha-synuclein antibody or antigen-binding fragment thereof to a subject every four weeks.

[0063] The method may comprise administering to the subject a fixed dose of 1,400 mg of an anti-alpha-synuclein antibody or antigen-binding fragment thereof every four weeks. The method may comprise administering to the subject a fixed dose of 1,600 mg of an anti-alpha-synuclein antibody or antigen-binding fragment thereof every four weeks. The method may comprise administering to the subject a fixed dose of 1,700 mg of an anti-alpha-synuclein antibody or antigen-binding fragment thereof every four weeks. The method may comprise administering to the subject a fixed dose of 1,800 mg of an anti-alpha-synuclein antibody or antigen-binding fragment thereof every four weeks.

[0064] According to the present invention, an anti-α-synuclein antibody or antigen-binding fragment thereof may be administered to a subject multiple times over a period of at least 3 months, 6 months, 9 months, 1 year, 2 years, or 5 years. An anti-α-synuclein antibody or antigen-binding fragment thereof may be administered to a subject twice a month over a period of at least 3 months, 6 months, 9 months, 1 year, 2 years, or 5 years. An anti-α-synuclein antibody or antigen-binding fragment thereof may be administered to a subject once a month over a period of at least 3 months, 6 months, 9 months, 1 year, 2 years, or 5 years. Preferably, an anti-α-synuclein antibody or antigen-binding fragment thereof is administered to a subject once every 4 weeks over a period of at least 3 months, 6 months, 9 months, 1 year, 2 years, or 5 years. Particularly preferably, an anti-α-synuclein antibody or antigen-binding fragment thereof is administered to a subject once every 4 weeks over a period of at least 1 year. Thus, the method may comprise administering to a subject a fixed dose of 1,200, 2,000, 2,400, 4,200, or 4,500 mg of an anti-alpha-synuclein antibody or antigen-binding fragment thereof once every four weeks for a period of at least one year. The method may comprise administering to a subject a fixed dose of 1,200 mg of an anti-alpha-synuclein antibody or antigen-binding fragment thereof once every four weeks for a period of at least one year. The method may comprise administering to a subject a fixed dose of 2,000 mg of an anti-alpha-synuclein antibody or antigen-binding fragment thereof once every four weeks for a period of at least one year. The method may comprise administering to a subject a fixed dose of 2,400 mg of an anti-alpha-synuclein antibody or antigen-binding fragment thereof once every four weeks for a period of at least one year. The method may comprise administering to the subject a fixed dose of 4,200 mg of an anti-alpha-synuclein antibody or antigen-binding fragment thereof once every four weeks for a period of at least one year.The method may comprise administering to the subject a fixed dose of 4,500 mg of an anti-alpha-synuclein antibody or antigen-binding fragment thereof once every four weeks for a period of at least one year.

[0065] The method may comprise administering to the subject a fixed dose of 1,400 mg of an anti-alpha-synuclein antibody or antigen-binding fragment thereof once every four weeks for a period of at least one year. The method may comprise administering to the subject a fixed dose of 1,600 mg of an anti-alpha-synuclein antibody or antigen-binding fragment thereof once every four weeks for a period of at least one year. The method may comprise administering to the subject a fixed dose of 1,700 mg of an anti-alpha-synuclein antibody or antigen-binding fragment thereof once every four weeks for a period of at least one year. The method may comprise administering to the subject a fixed dose of 1,800 mg of an anti-alpha-synuclein antibody or antigen-binding fragment thereof once every four weeks for a period of at least one year.

[0066] The anti-α-synuclein antibody or antigen-binding fragment thereof can be administered via any suitable route. For example, the anti-α-synuclein antibody or antigen-binding fragment thereof can be administered intravenously, intraperitoneally, transdermally, intracavity, subcutaneously, intradermally, or intramuscularly. Preferably, the anti-α-synuclein antibody or antigen-binding fragment thereof is administered intravenously.

[0067] As used herein and in accordance with the present invention, the term "α-synucleinopathy" or "alpha-synucleinopathy" refers to a neurodegenerative disease characterized by the abnormal accumulation of insoluble α-synuclein in neurons and glial cells in a subject. The term "α-synucleinopathy" is further discussed in Mendoza-Velasquez et al. (2019) Front. Neurol. 10:363, the entire contents of which are incorporated herein by reference. The α-synucleinopathy may be selected from Parkinson's disease (PD), dementia with Lewy bodies (DLB), and multiple system atrophy (MSA). The α-synucleinopathy may be selected from Alzheimer's disease, pure autonomic failure, and rapid eye movement (REM) behavior disorder. The α-synucleinopathy may be, for example, a pro-synucleinopathy characterized by early signs or symptoms of α-synucleinopathy, such as REM behavior disorder or autonomic symptoms such as orthostatic hypotension. Preferably, the α-synucleinopathy is PD or MSA.

[0068] The alpha-synucleinopathy may be Parkinson's disease (PD). The subject treated according to the present invention may have PD. The subject may have been diagnosed with PD. The subject may have one or more symptoms of PD, such as one or more of tremor, bradykinesia, impaired postural reflexes, and muscle rigidity. The subject may have been diagnosed with PD based on the Movement Disorder Society (MDS) clinical diagnostic criteria for Parkinson's disease (see, e.g., Postuma et al. (2015) Move. Disord. 30:1591-1599). The subject may be over 50 years old, for example, over 55 years old, over 60 years old, over 65 years old, over 70 years old, or over 75 years old. The subject may have early-onset PD. The subject may be under 50 years old. The subject may be at risk for PD. The subject may be predisposed to PD, for example, have a family history of PD, have a genetic predisposition to PD, and / or have been exposed to environmental factors associated with PD.

[0069] Preferably, the subject may have early PD. The subject may have been diagnosed with early PD. The subject may have been diagnosed with early PD. The subject may have one, two, three, four, five, six, seven, eight or more symptoms of early PD. Preferably, the subject has two or more symptoms of early PD. More preferably, the subject has two or more symptoms of early PD selected from tremor, slowed movement, and muscle stiffness. Symptoms of early PD may include one or more of: a) smaller handwriting, b) tremor, c) muscle stiffness, d) slowed movement, e) hunched posture, f) lack of facial expression, g) reduced arm swing, and h) soft or weak voice.

[0070] Alpha-synucleinopathy can be pure autonomic failure. Pure autonomic failure is a neurodegenerative disorder of the autonomic nervous system clinically characterized by orthostatic hypotension. Pure autonomic failure is described in detail in Coon et al. (2019) Mayo Clin. Proc. 94(10):2087-2098.

[0071] Alpha-synucleinopathies can be characterized by REM behavior disorder. REM behavior disorder (RBD) is characterized by REM sleep without atonia, along with recurrent nighttime dream patterns, accompanied by vocalizations such as yelling and screaming, and motor behaviors such as punching and kicking. RBD is described in detail in Barone and Henchcliffe (2018) Clin. Neurophysiol. 129(8):1551-1564.

[0072] The alpha-synucleinopathy may be MSA. The subject treated according to the present invention may have MSA. The subject may have been diagnosed with MSA. The subject may have one or more symptoms of MSA. The subject may be at risk for MSA. The subject may be susceptible to MSA. The subject may be at least 30 years old, at least 40 years old, at least 50 years old, at least 60 years old, or at least 70 years old. The subject may be at least 40 years old. The subject may be 50-60 years old.

[0073] Preferably, the subject has early stage MSA. The subject may have been diagnosed with early stage MSA. The subject may have been diagnosed with early stage MSA. The subject may have one, two, three, four, or five or more symptoms of early stage MSA. Preferably, the subject has two or more symptoms of early stage MSA. More preferably, the subject has two or more symptoms of early stage PD selected from tremor, slowed movement, and muscle rigidity. Symptoms of early stage MSA may include one or more of the following: a) slowness, tremor, or rigidity (stiffness), b) clumsiness or incoordination, c) speech impairment, hoarse, trembling voice, d) fainting or lightheadedness due to orthostatic hypotension, and e) bladder control problems, such as sudden urgency to urinate or difficulty emptying the bladder.

[0074] A subject may have been diagnosed with possible or probable MSA. As used herein, the term "possible or probable MSA" refers to possible or probable MSA as defined using the modified Gilman et al., 2008 diagnostic criteria, as described in detail in Gilman et al. (2008) Neurol. 71(9):670-676.

[0075] The possible diagnostic criteria for MSA are as follows: (1) A sporadic, progressive, adult-onset (age 30 or older) disease characterized by: a) Parkinson's disease (bradykinesia with rigidity, tremor, or impaired postural control) or cerebellar syndrome (gait ataxia with cerebellar dysarthria, limb ataxia, or cerebellar oculomotor dysfunction), and b) at least one feature suggestive of autonomic dysfunction (unexplained urgency, frequent or incomplete bladder emptying, erectile dysfunction in male subjects, or marked orthostatic hypotension below the level required for unlikely MSA), and (2) At least one of the following additional characteristics: For possible MSA with predominant parkinsonism (MSA-P) or MSA with predominant cerebellar ataxia (MSA-C): a) Babinski sign due to hyperreflexia, and / or b) Wheezing. For possible Parkinson's disease-predominant MSA (MSA-P): a) Rapidly progressive Parkinson's disease, b) low levodopa responsiveness, c) Postural instability within 3 years of starting exercise; d) gait ataxia, cerebellar dysarthria, limb ataxia, or cerebellar oculomotor dysfunction; e) dysphagia within 5 years of starting exercise; f) atrophy on MRI of the putamen, middle cerebellar peduncle, pons, or cerebellum; and / or g) Hypometabolism on fluorodeoxyglucose (FDG)-positron emission tomography (PET) in the putamen, brainstem, or cerebellum. Regarding possible cerebellar ataxia-predominant MSA (MSA-C), a) Parkinson's disease (bradykinesia and rigidity), b) atrophy of the putamen, middle cerebellar peduncle, or pons on MRI; c) hypometabolism on FDG-PET in the putamen, and / or d) Presynaptic nigrostriatal dopaminergic denervation with single photon emission computed tomography or PET.

[0076] The diagnostic criteria for probable MSA are as follows: A sporadic, progressive, adult (age 30 and older) onset disease characterized by: a) autonomic failure with urinary incontinence (inability to control the release of urine from the bladder, accompanied by erectile dysfunction in male subjects) or a drop in orthostatic blood pressure during standing to at least 30 mmHg systolic or 15 mmHg diastolic within 3 minutes, and b) Levodopa-hyporesponsive Parkinson's disease (bradykinesia with rigidity, tremor, or impaired postural control), or c) Cerebellar syndrome (gait disorder with cerebellar dysarthria, limb ataxia, or cerebellar oculomotor dysfunction).

[0077] A subject may have been diagnosed with "clinically established MSA," "clinically probable MSA," or "possible precursor MSA." As used herein, the terms "clinically established MSA," "clinically probable MSA," and "probable precursor MSA" refer to clinically established MSA, clinically probable MSA, and possible precursor MSA, respectively, as defined in Wenning et al. (2022) Mov. Disor. 37(6):1131-1148.

[0078] Clinically established diagnostic criteria for MSA are as follows: (1) A sporadic, progressive, adult-onset (age 30 or older) disease characterized by: (a) Unexplained difficulty in urination with post-void residual urine volume ≥ 100 mL; (b) unexplained urge incontinence, and (c) neurogenic OH (≥20 / 10 mmHg blood pressure drop) during standing or head-up tilt test within 3 minutes, and (a) Low L-dopa responsive Parkinson's disease, and (b) cerebellar syndrome (at least two of the following: gait disturbance, limb ataxia, and cerebellar dysarthria) or eye movement characteristics, and (2) At least two supportive clinical (motor or nonmotor) features selected from the following: (a) rapid progression within the first 3 years of exercise; (b) moderate to severe impairment of postural stability within 3 years of starting exercise; (c) craniocervical dystonia induced or exacerbated by L-dopa in the absence of limb dyskinesias; (d) severe language impairment within 3 years of exercise initiation; (e) severe dysphagia within 3 years of starting exercise; (f) Babinski sign of unknown cause; (g) spastic myoclonic postural or kinetic tremor; (h) Postural deformity, (i) wheezing, (j) deep inhalation (inspiratory sigh), (k) Cool-toned discoloration of the hands and feet, and (l) Pathological laughing or crying; and (3) At least one MRI marker selected from the following (one MRI marker for each affected brain region evidenced by either atrophy or increased diffusivity counts): About MSA-P: (a) Atrophy of: (i) putamen (and reduced signal on iron-sensitive sequences); (ii) middle cerebellar peduncle; (iii) the pons, or (iv) cerebellum, (b) "hot cross bun" symptoms, and (c) Increase the diffusivity of: (i) putamen, or (ii) middle cerebellar peduncle; About MSA-C: (a) Atrophy of: (i) putamen (and reduced signal on iron-sensitive sequences), or (ii) infratentorial structures (pons and middle cerebellar peduncle); (b) "hot cross bun" symptoms, and (c) increased putamen diffusivity, and (4) All of the following characteristics are absent: (a) a substantial and sustained beneficial response to dopamine agonists; (b) unexplained anosmia on olfactory testing; (c) fluctuating cognition, with marked fluctuations in attention and alertness and an early decline in visual-perceptual abilities; (d) recurrent visual hallucinations not induced by drugs within 3 years of disease onset; (e) dementia according to DSM-V within 3 years of illness onset; (f) Downward gaze supranuclear palsy or slowing of vertical saccades; (g) Alternative diagnoses (e.g., PSP, multifocal brain MRI findings suggestive of cerebellar sclerosis, vascular Parkinsonism, and symptomatic cerebellar disease, and (h) Documentation of alternative conditions (MSA-like conditions, including genetic or syndromic ataxia and Parkinson's disease) known to cause autonomic failure, ataxia, or Parkinson's disease and possibly related to the patient's symptoms.

[0079] The diagnostic criteria for clinically probable MSA are as follows: (1) A sporadic, progressive, adult-onset (age 30 or older) disease characterized by: At least two of the following (a) to (c): (a) Autonomic dysfunction, defined as: (i) Unexplained difficulty urinating with post-void residual urine, (ii) unexplained urge incontinence, and (iii) neurogenic OH (≥20 / 10 mmHg blood pressure drop) during standing or head-up tilt test within 10 minutes; (b) Parkinson's disease, and (c) cerebellar syndrome (defined as at least one of the following: gait ataxia, limb ataxia, cerebellar dysarthria, and oculomotor features); (2) At least one supportive clinical (motor or nonmotor) feature selected from the following: (a) rapid progression within the first 3 years of exercise; (b) moderate to severe impairment of postural stability within 3 years of starting exercise; (c) craniocervical dystonia induced or exacerbated by L-dopa in the absence of limb dyskinesias; (d) severe language impairment within 3 years of exercise initiation; (e) severe dysphagia within 3 years of starting exercise; (f) Babinski sign of unknown cause; (g) spastic myoclonic postural or kinetic tremor; (h) Postural deformity, (i) wheezing, (j) deep inhalation, (k) Cool-toned discoloration of the hands and feet, and (l) Pathological laughing or crying; and (3) All of the following characteristics are absent: (a) a substantial and sustained beneficial response to dopamine agonists; (b) unexplained anosmia on olfactory testing; (c) cognitive fluctuations, with marked fluctuations in attention and alertness and an early decline in visual-perceptual abilities; (d) recurrent visual hallucinations not induced by drugs within 3 years of disease onset; (e) dementia according to DSM-V within 3 years of illness onset; (f) Downward gaze supranuclear palsy or slowing of vertical saccades; (g) Alternative diagnoses (e.g., PSP, multifocal brain MRI findings suggestive of cerebellar sclerosis, vascular Parkinsonism, and symptomatic cerebellar disease, and (h) Documentation of alternative conditions (MSA-like conditions, including genetic or syndromic ataxia and Parkinson's disease) known to cause autonomic failure, ataxia, or Parkinson's disease and possibly related to the patient's symptoms.

[0080] The diagnostic criteria for possible prodromal MSA are as follows: (1) A sporadic, progressive, adult-onset (age 30 or older) disease characterized by: (a) RBD (proven by polysomnography); (b) neurogenic OH (≥20 / 10 mmHg blood pressure drop) during standing or head-up tilt testing within 10 minutes, and (c) urogenital dysfunction (erectile dysfunction in men under 60 years of age combined with at least one of unexplained difficulty in voiding with post-void residual urine volume >100 mL and unexplained urge urinary incontinence); and (2) At least one of the following: (a) subtle Parkinson's symptoms, and (b) subtle cerebellar signs, and (3) All of the following are absent: (a) Unexplained anosmia or abnormal cardiac sympathetic nerve imaging on olgactory examination 123 I-MIBG-scintigraphy), (b) cognitive fluctuations, with marked fluctuations in attention and alertness and an early decline in visual-perceptual abilities; (c) recurrent visual hallucinations not induced by drugs within 3 years of disease onset; (d) dementia according to DSM-V within 3 years of illness onset; (e) Downward gaze supranuclear palsy or slowing of vertical saccades; (f) brain MRI findings suggestive of alternative diagnoses (e.g., PSP, multiple sclerosis, vascular Parkinson's disease, symptomatic cerebellar disease, etc.); and (g) Documentation of alternative conditions (MSA-like conditions, including genetic or syndromic ataxia and Parkinson's disease) known to cause autonomic failure, ataxia, or Parkinson's disease and possibly related to the patient's symptoms.

[0081] Subjects to be treated according to the present invention can be defined or selected based on their score on the Unified Multiple System Atrophy Rating Scale. The subject may have a Unified Multiple System Atrophy Rating Scale (UMSARS) Part I score of 40 or less. The subject may have a Unified Multiple System Atrophy Rating Scale (UMSARS) Part I score of 30 or less. Preferably, the subject has a Unified Multiple System Atrophy Rating Scale (UMSARS) Part I score of 24 or less. The UMSARS score (Wenning et al. (2004) Mov. Disord. 19(12):1391-1402) is a clinical rating scale designed to assess the severity of MSA in subjects, with higher scores indicating more severe disease. The UMSARS includes four subscales: UMSARS Part I (12 questions) assesses patient-reported functional impairment, UMSARS Part II (14 questions) assesses clinician-assessed movement impairment, UMSARS Part III records supine and standing blood pressure and heart rate measurements, and UMSARS Part IV (1 question) assesses work-based disability. Responses to UMSARS Part I and Part II questions or items are scored from 0 to 4, with a score of 0 indicating normal function and a score of 1 indicating mild disability. Subjects may have a severity score of 2 or less for the swallowing item. Subjects may have a severity score of 2 or less for the gait item. Subjects may have a severity score of 2 or less for the falls item. Subjects may have a UMSARS Part IV disability score of 3 or less. Subjects may have a UMSARS Part I score of 21 or less. Preferably, when these scores are used herein to define subjects to be treated in accordance with the present invention, they refer to the subject's score at baseline, i.e., the subject's score immediately before the start of treatment with the anti-alpha-synuclein antibody or antigen-binding fragment thereof.

[0082] The subject to be treated (e.g., at baseline) may have a Montreal Cognitive Assessment (MoCA) score of 18 or greater. The MoCA test was developed to detect mild cognitive impairment, but is now frequently used as a screening tool for dementia. The MoCA is a brief test of cognitive function that is scored out of 30 points and takes 10 minutes to administer. It assesses short-term memory, visuospatial function, executive function, attention, concentration and working memory, language, and orientation. The MoCA test is described in detail in Nasreddine et al. (2005) J. Amer. Geriatrics Soc. 53(4):659-9. 4.1.1 Clinical outcomes

[0083] The present invention relates to treating or preventing α-synucleinopathy. Treatment or prevention may be observed as a decrease in one or more markers and / or symptoms of α-synucleinopathy and / or a decrease in the score from one or more relevant scoring systems for α-synucleinopathy. For example, in a subject treated according to the present invention, the subject's condition may improve. In a subject treated according to the present invention, one or more symptoms and / or markers and / or scores of α-synucleinopathy may improve. Treatment or prevention may be observed as a reduction in the progression of α-synucleinopathy in a subject or a delay in the progression of α-synucleinopathy in a subject. For example, in a subject treated according to the present invention, the subject's condition may stabilize or remain stable. In a subject treated according to the present invention, one or more symptoms and / or markers and / or scores of α-synucleinopathy may remain stable, stabilize, or not worsen. In a subject treated according to the present invention, alpha-synucleinopathy may continue to progress, but may continue to progress at a slower rate than would be expected for a subject with that type of alpha-synucleinopathy or at that stage of the disease. Alpha-synucleinopathy progression can be measured by assessing one or more markers and / or symptoms and / or scores of alpha-synucleinopathy in a subject at two or more time points (e.g., before treatment according to the present invention (e.g., at baseline) and during and / or after treatment) and determining whether there has been any change over that time period. Reduction or delay in progression can be measured by comparing progression in a subject treated with an antibody or antigen-binding fragment thereof described herein with the change in the same marker and / or symptom and / or score over the same time period in subjects not treated with such an antibody or antigen-binding fragment thereof (e.g., control or placebo-treated subjects or a control or placebo-treated group). Preferably, the comparison is with a placebo-treated subject, e.g., the typical change or mean change in score obtained from the placebo-treated subject group. Preferably, control or placebo-treated subjects are subjects with the same disease or disorder as the subject being treated.Preferably, control or placebo-treated subjects have the same or similar level of disease progression as treated subjects at the start of treatment. Preferably, control or placebo-treated subjects have the same range or similar score as treated subjects at the start of treatment. A reduction or delay in progression can be measured by comparing progression in subjects treated with an antibody or antigen-binding fragment thereof as described herein to the changes in the same markers and / or symptoms and / or scores that would be expected or predicted over the same period in subjects not treated with such an antibody or antigen-binding fragment thereof, e.g., based on a model of disease progression, e.g., normal or average levels in a reference subject having the same disease or disorder or the same alpha-synucleinopathic disease as the subject, or having the same degree of disease progression as the treated subject.

[0084] Treating or preventing in the present invention can be observed as a decrease, stabilization, or slowing or attenuation of progression of (i) α-synuclein diffusion in the subject, (ii) α-synuclein levels in the subject's cerebrospinal fluid (CSF), and / or (iii) α-synuclein levels in the subject's brain interstitial fluid (ISF). Thus, the present methods may reduce the progression of α-synucleinopathic disease as measured by α-synuclein diffusion in the subject, the level of free, unbound α-synuclein in the subject's CSF, and / or the level of free, unbound α-synuclein in the subject's ISF. The present methods may reduce the progression of α-synucleinopathic disease as measured by α-synuclein diffusion in the subject and the level of free, unbound α-synuclein in the subject's CSF. The present methods may reduce the progression of α-synucleinopathic disease as measured by α-synuclein diffusion in the subject. Preferably, the method reduces the progression of α-synucleinopathic disease as measured by the level of free, unbound α-synuclein in the subject's CSF. The method may reduce the progression of α-synucleinopathic disease as measured by the level of free, unbound α-synuclein in the subject's brain interstitial fluid. Advantageously, these effects may be achieved by intravenously administering an anti-α-synuclein antibody or antigen-binding fragment thereof.

[0085] The methods disclosed herein may provide advantages over other therapeutic agents by reducing α-synuclein diffusion in a subject, reducing α-synuclein levels in the subject's CSF, and / or reducing α-synuclein levels in the subject's brain interstitial fluid. Thus, the methods may reduce α-synuclein diffusion in a subject, reduce free, unbound α-synuclein levels in the subject's CSF, and / or reduce free, unbound α-synuclein levels in the subject's ISF. The methods may reduce α-synuclein diffusion in a subject and reduce free, unbound α-synuclein levels in the subject's CSF. The methods may reduce α-synuclein diffusion in a subject. Preferably, the methods reduce free, unbound α-synuclein levels in the subject's cerebrospinal fluid (CSF). The methods may reduce free, unbound α-synuclein levels in the subject's brain interstitial fluid (ISF). Advantageously, the anti-alpha-synuclein antibody or antigen-binding fragment thereof, when administered intravenously, may reduce alpha-synuclein diffusion, reduce free unbound alpha-synuclein levels in cerebrospinal fluid, and / or reduce free unbound alpha-synuclein levels in brain interstitial fluid.

[0086] Alpha-synuclein diffusion in a subject can be measured by any suitable means. Alpha-synuclein is abundant in the central nervous system (CNS) and brain, where it is found both intracellularly in neurons and glia, and extracellularly in the cerebrospinal fluid (CSF) (Mollenhauer et al. (2012) J. Neural. Transm. (2012), 119(7):739-46, incorporated herein by reference) and interstitial fluid (ISF) that bathes and surrounds brain cells (Emmanouilidou et al. (2011) PLoS One (2011), 6(7):e22225, incorporated herein by reference). Alpha-synuclein is a synaptic protein that is primarily expressed in neurons of the neocortex, hippocampus, substantia nigra, thalamus, and cerebellum (Iwai et al. (1995) Neuron (1995), 14:467-475, incorporated herein by reference). Under physiological conditions, it is located at the synaptic terminals of neurons and is specifically upregulated at presynaptic terminals during acquisition-related synaptic reorganization (Fortin et al. (2005) J. Neurosci. (2005), 25:10913-10921, incorporated herein by reference). A variety of different experimental models have demonstrated the intercellular transmission of alpha-synuclein in cultured cells or the spread and propagation of alpha-synuclein pathology in vivo. For example, preformed recombinant alpha-synuclein fibrils and alpha-synuclein oligomers can be internalized by cultured cells and neurons, and direct transfer of alpha-synuclein from donor cells to recipient cells has been demonstrated, accompanied by the formation of alpha-synuclein inclusions similar to Lewy pathology (Danzer et al. (2007) J. Neurosci. (2007), 27(34):9220-32; Volpicelli-Daley et al. (2011) Neuron (2011), 72(1):57-71; and Luk et al. (2009) Proc. Natl. Acad. Sci. USA (2009), 106(47):20051-6, each of which is incorporated herein by reference).Furthermore, the trafficking and transmission of both monomeric and oligomeric alpha-synuclein from the olfactory bulb to interconnected brain structures has been demonstrated in mice (Rey et al. (2013) Acta Neuropathol. (2013), 126(4):555-73, incorporated herein by reference).

[0087] As used herein, the term "α-synuclein spreading" refers to the expansion of the area where α-synuclein is found. This can relate to the expansion of the area where misfolded α-synuclein or aggregated α-synuclein, such as Lewy bodies or Lewy body-like aggregates, are found. α-synuclein spreading can include spreading of α-synuclein to wider areas of the brain or to additional areas of the brain. α-synuclein spreading can include spreading of α-synuclein to wider areas of the periphery or to additional areas of the periphery. α-synuclein spreading can include movement of α-synuclein via cell-to-cell communication. For example, α-synuclein oligomers can be released into the extracellular environment and taken up by neighboring cells in a "spreading" mechanism (Angot and Brundin (2009) Parkinsonism Relat. Disord. 15 Suppl 3:S143-147; Desplats et al. (2009) Proc. Natl. Acad. Sci. USA 106:13010-13015; and Lee et al. (2010) J. Biol. Chem. 285:9262-9272). α-Synuclein diffusion can involve the diffusion of misfolded α-synuclein, such as α-synuclein oligomers or polymers, or other forms of aggregated α-synuclein, such as the formation of Lewy bodies or Lewy body-like aggregates, or diffusion to wider or further regions of the brain. For example, this can occur through the propagation of α-synuclein misfolding via a prion-like diffusion mechanism (Lee et al. (2010) Nat. Rev. Neurol. 6:702-706, Luk et al. (2012) J. Exp. Med. 209(5):975-86, and Luk et al. (2012) Science 338(6109):949-54). α-Synuclein diffusion may occur within a single region of the brain and / or may involve diffusion to different regions of the brain, e.g., interconnected or adjacent brain regions. Preferably, the present invention results in a reduction of α-synuclein diffusion in a subject.A reduction in α-synuclein diffusion can include a reduction in the extent of diffusion in a subject compared to that seen in a control subject not administered an anti-α-synuclein antibody or antigen-binding fragment thereof in accordance with the present invention. A reduction in α-synuclein diffusion can include a reduction in the extent of diffusion compared to a reference level of diffusion. The reference level of α-synuclein diffusion can be based on a model of disease progression, e.g., the normal or average level of α-synuclein diffusion in a reference subject having the same disease or disorder or the same α-synucleinopathy as the subject, or a reference subject having the same extent of disease progression as the subject being treated. A reference level of α-synuclein diffusion can be based on the amount of diffusion seen in one or more control subjects over a similar period of time, such as a population of control subjects not administered an anti-α-synuclein antibody or antigen-binding fragment thereof in accordance with the present invention, such as one or more placebo-treated subjects. A reduction in α-synuclein diffusion can be a reduction in the amount of α-synuclein in the diffusion zone compared to the reference level, e.g., a lower amount of α-synuclein in the diffusion zone. A decrease in alpha-synuclein diffusion can be a decrease in the extent of diffusion compared to a reference level, such as a decrease in the number of regions through which alpha-synuclein diffuses or a decrease in the area or volume of diffusion. A decrease in alpha-synuclein diffusion can be a decrease or slowing of the progress of alpha-synuclein diffusion compared to a reference level, for example a decrease or slowing of alpha-synuclein diffusion within a region or to a different region.

[0088] The level of free, unbound α-synuclein in a subject's CSF can be measured by any suitable means. As used herein, the term "free, unbound α-synuclein" refers to α-synuclein that is not bound to an anti-α-synuclein antibody or antigen-binding fragment thereof. The free, unbound α-synuclein can apply to α-synuclein in its monomeric or oligomeric form, or aggregated form. These terms generally apply to any pathological form of α-synuclein. Thus, the level of free, unbound α-synuclein in a sample can be assessed by a method comprising separating α-synuclein bound to an antibody or fragment from α-synuclein not bound to the antibody or fragment. The level of free, unbound α-synuclein in a subject's CSF can be measured by a method comprising removing α-synuclein bound to an antibody or antigen-binding fragment thereof from a sample of CSF and then assessing the amount of α-synuclein remaining in the sample. For example, a CSF sample can be subjected to immunoprecipitation (IP) to remove α-synuclein bound to the antibody or its antigen-binding fragment, leaving unbound "free" α-synuclein in the supernatant. The free level of α-synuclein remaining in the CSF sample (e.g., supernatant) can then be determined by any suitable method, such as ELISA. For example, the level of free α-synuclein in the CSF supernatant can be assessed using a commercially available ELISA kit, such as the Mesoscale Discovery ELISA kit (see Example 1) or the Sensolyte™ Quantitative ELISA kit, human / mouse / rat, AnaSpec, US, AS-55550. As used herein, "sample" can refer to an in vitro or ex vivo sample obtained from a suitable subject. A CSF sample can be collected from a subject by lumbar puncture.A change or decrease in the level of free, unbound alpha-synuclein in the CSF can be determined by comparing the level of free, unbound alpha-synuclein in CSF samples taken from the subject at different time points (e.g., before treatment in accordance with the invention (e.g., at baseline), and during and / or after treatment) and determining whether there has been any change over that time period. A CSF sample can be obtained from the subject before the initiation of a method of the invention or before administration forming part of a method of the invention, and compared with one or more CSF samples obtained from the subject during and / or after a method of the invention, e.g., a CSF sample taken after one or more administrations of an antibody or antigen-binding fragment thereof in accordance with the invention. A decrease in free, unbound alpha-synuclein in the CSF can include a decrease in the level of alpha-synuclein in the CSF of a subject during a method of the invention (e.g., a level after a method of the invention is lower compared to the level in the CSF of the subject before a method of the invention (e.g., at baseline)). A reduction in free, unbound α-synuclein in the CSF can be a reduction or delay in the progression of the level of free, unbound α-synuclein in the CSF compared to that seen in control subjects who are not administered an anti-α-synuclein antibody or antigen-binding fragment thereof in accordance with the invention. A reduction in α-synuclein diffusion can include a reduction or delay in the progression of the level of free, unbound α-synuclein in the CSF compared to a reference level of free, unbound α-synuclein. The reference level of free, unbound α-synuclein can be based on a model of disease progression, for example, the normal or average level of free, unbound α-synuclein in the CSF in a reference subject having the same disease or disorder or the same α-synucleinopathic disease as the subject, or a reference subject having the same degree of disease progression as the subject being treated. The reference level of free, unbound alpha-synuclein may be based on the amount of free, unbound alpha-synuclein found in the CSF of one or more control subjects, such as a population of control subjects who have not been administered an anti-alpha-synuclein antibody or antigen-binding fragment thereof in accordance with the invention, such as one or more placebo-treated subjects. One or more CSF samples obtained from a subject during and / or after a method of the invention, e.g., a CSF sample taken after one or more administrations of an antibody or antigen-binding fragment thereof in accordance with the invention, may be compared to one or more CSF samples obtained from one or more placebo-treated subjects.The level of free, unbound alpha-synuclein may be assessed in CSF samples, or the relative levels of free, unbound alpha-synuclein may be compared between CSF samples. The amount (or relative amount) of free, unbound alpha-synuclein can then be compared between CSF samples taken at different time points relative to the methods of the invention to determine whether the methods of the invention, or administration of one or more doses of an antibody or antigen-binding fragment thereof, reduced the amount of free, unbound alpha-synuclein in the CSF. A lower level of free, unbound alpha-synuclein in the CSF during or after the methods of the invention, compared to the level of free, unbound alpha-synuclein in the subject's CSF before the methods of the invention, may indicate that the methods of the invention result in a reduction of free, unbound alpha-synuclein in the CSF. A lower level of free, unbound α-synuclein in the subject's CSF during or after the methods of the invention compared to the level of free, unbound α-synuclein in a control or placebo-treated subject, or compared to a reference level of free, unbound α-synuclein, may indicate that the methods of the invention result in a reduction of free, unbound α-synuclein in the CSF. A delayed or reduced increase in the level of free, unbound α-synuclein in the subject's CSF (based on a comparison of the level before (e.g., at baseline) with the level during or after the methods of the invention) compared to the level of free, unbound α-synuclein in the CSF over the same time period in a control or placebo-treated subject, or compared to a reference level of change in free, unbound α-synuclein, indicates that the methods of the invention result in a reduction of free, unbound α-synuclein in the CSF.

[0089] The level of free, unbound α-synuclein in a subject's brain ISF can be measured by any suitable means. For example, an ISF sample can be collected by microdialysis, as described, for example, in Herukka et al. (2015) J. Alzheimers Dis. 46(1):261-9. The level of free, unbound α-synuclein in an ISF sample can be assessed by methods described above for measuring the level of free, unbound α-synuclein in CSF, for example, by methods including separating α-synuclein bound to an antibody or fragment from α-synuclein not bound to the antibody or fragment. For example, an ISF sample can be subjected to immunoprecipitation to remove α-synuclein bound to the antibody or its antigen-binding fragment. The free level of α-synuclein in the remaining supernatant can be determined, for example, by ELISA. Changes in the level of free, unbound α-synuclein in ISF can be determined by comparing the levels of α-synuclein in ISF samples collected from a subject at different time points, using the same methods described above for assessing a decrease in CSF samples. A change or decrease in the level of free, unbound alpha-synuclein in the ISF can be determined by comparing the level of free, unbound alpha-synuclein in ISF samples taken from a subject at different time points (e.g., before treatment according to the invention (e.g., at baseline), and during and / or after treatment) and determining whether there has been any change over that time period. An ISF sample obtained from a subject before the initiation of a method of the invention, or before administration forming part of a method of the invention, can be compared with one or more ISF samples obtained from the subject during and / or after a method of the invention, e.g., an ISF sample taken after one or more administrations of an antibody or antigen-binding fragment thereof in accordance with the invention. Alternatively, one or more ISF samples obtained from a subject during and / or after a method of the invention, e.g., an ISF sample taken after one or more administrations of an antibody or antigen-binding fragment thereof in accordance with the invention, can be compared with one or more ISF samples obtained from a placebo-treated subject. The level of free, unbound alpha-synuclein may be assessed in the ISF samples, or the relative levels of free, unbound alpha-synuclein may be compared between ISF samples.A reduction in free, unbound α-synuclein in the ISF can include a reduction in the level of α-synuclein in the subject's ISF during a method of the invention (e.g., a lower level after a method of the invention compared to the level in the subject's ISF before a method of the invention (e.g., at baseline)). A reduction in free, unbound α-synuclein in the ISF can be a reduction or delay in the progression of the level of free, unbound α-synuclein in the ISF compared to that seen in a control subject not administered an anti-α-synuclein antibody or antigen-binding fragment thereof in accordance with the invention. A reduction in α-synuclein diffusion can include a reduction or delay in the progression of the level of free, unbound α-synuclein in the ISF compared to a reference level of free, unbound α-synuclein. The reference level of free, unbound α-synuclein can be based on a model of disease progression, for example, the normal or average level of free, unbound α-synuclein in the ISF in a reference subject having the same disease or disorder or the same α-synucleinopathic disease as the subject, or a reference subject having the same degree of disease progression as the subject being treated. The reference level of free, unbound α-synuclein can be based on the amount of free, unbound α-synuclein found in the ISF of one or more control subjects, such as a population of control subjects not administered an anti-α-synuclein antibody or antigen-binding fragment thereof in accordance with the invention, such as one or more placebo-treated subjects. One or more ISF samples obtained from a subject during and / or after a method of the invention, e.g., an ISF sample collected after one or more administrations of an antibody or antigen-binding fragment thereof in accordance with the invention, can be compared with one or more ISF samples obtained from one or more placebo-treated subjects. The level of free, unbound α-synuclein can be assessed in the ISF samples, or the relative levels of free, unbound α-synuclein can be compared between ISF samples. The amount (or relative amounts) of free, unbound α-synuclein can then be compared between ISF samples collected at different time points relative to the method of the invention to determine whether the method of the invention or the administration of one or more doses of an antibody or antigen-binding fragment thereof reduced the amount of free, unbound α-synuclein in the ISF.A lower level of free, unbound alpha-synuclein in the ISF during or after a method of the invention compared to the level of free, unbound alpha-synuclein in the subject's ISF before the method of the invention may indicate that the method of the invention results in a reduction of free, unbound alpha-synuclein in the ISF. A lower level of free, unbound alpha-synuclein in the ISF of a subject during or after a method of the invention compared to the level of free, unbound alpha-synuclein in a control or placebo-treated subject, or compared to a reference level of free, unbound alpha-synuclein, may indicate that the method of the invention results in a reduction of free, unbound alpha-synuclein in the ISF. A delayed or reduced increase in the level of free, unbound alpha-synuclein in the ISF of a subject (based on a comparison of the level before (e.g., at baseline) with the level during or after a method of the invention) when compared to the level of free, unbound alpha-synuclein in the ISF over the same time period in a control or placebo-treated subject, or compared to a change during or after a method of the invention when compared to a reference level of change in free, unbound alpha-synuclein, may indicate that the method of the invention results in a reduction of free, unbound alpha-synuclein in the ISF.

[0090] Treatment with an anti-α-synuclein antibody or antigen-binding fragment thereof according to the invention may alter (e.g., improve, inhibit, reduce, stabilize, or slow or reduce the progression of) one or more symptoms or characteristics of α-synucleinopathies in a subject based on scoring or measurement of one or more clinical scales, outcomes, or symptoms in the subject, e.g., based on a clinical scoring system. Various well-known clinical scoring systems exist for the assessment of subjects with α-synucleinopathies. Treatment with an anti-α-synuclein antibody or antigen-binding fragment thereof according to the invention may alter (e.g., improve, inhibit, reduce, stabilize, or slow or reduce the progression of) a subject's score in any such scoring system, such as the subject's UMSARS, CGI-S, SCOPA AUT, or MDS-UPDRS score, as described herein. Preferably, any reduction in score or level described herein is a reduction compared to the score of a subject not treated with such anti-α-synuclein antibody or antigen-binding fragment thereof (e.g., a control or placebo-treated subject, or a control or placebo-treated group of subjects). Thus, a reduction in score or level described herein compared to such a control indicates a reduction in the progression of α-synucleinopathic disease. For example, the methods of the invention may reduce the score in a subject, e.g., based on a comparison between the subject's score before (e.g., at baseline) and the subject's score during or after the methods of the invention. The methods of the invention may slow or reduce an increase in the score in a subject, which may reflect a slowing or reduction in the progression of α-synucleinopathic disease in the subject. For example, the score may be stabilized (e.g., the score may not increase), e.g., based on a comparison between the subject's score before (e.g., at baseline) and the subject's score during or after the methods of the invention. The change in score (e.g., based on a comparison of the subject's score before (e.g., at baseline) the method of the invention with the subject's score during or after the method of the invention) may be less than that expected based on a control, such as a control subject not administered an anti-alpha-synuclein antibody or antigen-binding fragment thereof in accordance with the invention.For example, the change in score in a subject may be reduced or delayed compared to a reference value representing an expected change in score for such a subject over that period of time. This may reflect a delay or reduction in the progression of alpha-synucleinopathic disease in the subject. The reference value may be based on a model of disease progression, e.g., the normal level or mean score or change in score seen in reference subjects with the same disease or disorder or the same alpha-synucleinopathic disease as the subject, or reference subjects with the same degree of disease progression as the subject being treated. The reference value may be based on the score of one or more control subjects, such as a population of control subjects not administered an anti-alpha-synuclein antibody or antigen-binding fragment thereof in accordance with the invention, such as one or more placebo-treated subjects. The reference value may be based on the change in score of one or more control subjects over the same period of time, such as a population of control subjects not administered an anti-alpha-synuclein antibody or antigen-binding fragment thereof in accordance with the invention, such as one or more placebo-treated subjects.

[0091] The score may be a UMSARS score. The score may be a modified version of UMSARS Part I. The method may reduce the progression of alpha-synucleinopathy as measured by the modified version of UMSARS Part I. Thus, treatment with an anti-alpha-synuclein antibody or antigen-binding fragment thereof may reduce a subject's score on the modified version of UMSARS Part I. Preferably, the method reduces the progression of alpha-synucleinopathy as measured by the modified version of UMSARS Part I. UMSARS Part I may be modified to include fewer than 12 questions. UMSARS Part I may be modified so that answers to questions are scored 0-3 or 1-4.

[0092] Treatment with an anti-alpha-synuclein antibody or antigen-binding fragment thereof may reduce a subject's UMSARS total score. The method may reduce the progression of alpha-synucleinopathies as measured by the UMSARS total score. The UMSARS total score may include all items from UMSARS parts I, II, III, and IV. The UMSARS total score may include all items from the modified UMSARS part I and all items from UMSARS parts II, III, and IV.

[0093] Treatment with an anti-alpha-synuclein antibody or antigen-binding fragment thereof may reduce a subject's UMSARS part I score. The method may reduce the progression of alpha-synucleinopathy as measured by the UMSARS part I score.

[0094] Treatment with an anti-alpha-synuclein antibody or antigen-binding fragment thereof may reduce a subject's UMSARS part II score. The method may reduce the progression of alpha-synucleinopathy as measured by the UMSARS part II score.

[0095] Treatment with an anti-α-synuclein antibody or antigen-binding fragment thereof may reduce a subject's 11-item UMSARS score. The method may reduce the progression of α-synucleinopathies as measured by the 11-item UMSARS score. The 11-item UMSARS score is described in Palma et al. (2021) Clinical Auton. Res. 31:157-164 and consists of UMSARS Part I questions 2, 3, 6, 7, and 11 and UMSARS Part II questions 1, 2, 9, 11, 12, and 14. These 11 items demonstrated the highest cumulative normalized effect in a longitudinal natural history analysis from the Natural History Study of the Synucleinopathies.

[0096] Treatment with an anti-α-synuclein antibody or antigen-binding fragment thereof may reduce a subject's Clinical Global Impression-Severity (CGI-S) scale score. The method may reduce the progression of α-synucleinopathies as measured by the CGI-S scale score. The CGI-S (described in detail by Busner and Targum (2007) Psychiatry (Edgmont) 4(7):28-37) is used to assess a clinician's impression of a subject's clinical status. The clinician scores the subject's illness severity on a 7-point scale ranging from 1 for normal, not at all ill, to 7 for the most extremely ill patient. The assessment is based on observed and reported symptoms, behavior, and function over the past 7 days and should reflect the average severity level over the 7-day period.

[0097] Treatment with an anti-α-synuclein antibody or antigen-binding fragment thereof may reduce a subject's score on the Scales for Outcomes in Parkinson's Disease-Autonomic Dysfunction (SCOPA-AUT) test. The method may reduce the progression of α-synucleinopathies as measured by the SCOPA-AUT test. The SCOPA-AUT (described in detail in Visser et al. (2004) Mov. Disord. 19(11):1306-12) is used to assess autonomic symptoms in patients with Parkinson's disease. The scale is self-completed by patients and consists of 25 items assessing gastrointestinal, urinary, cardiovascular, thermoregulatory, pupillary, and sexual symptoms.

[0098] Treatment with an anti-alpha-synuclein antibody or antigen-binding fragment thereof (eg, a fixed dose every four weeks for at least one year) may improve survival compared to placebo.

[0099] Treatment with an anti-α-synuclein antibody or its antigen-binding fragment may reduce a subject's score on the Movement Disorder Society-Sponsored Revision of the Unified Parkinson's Disease Rating Scale (MDS-UPDRS). The method may reduce the progression of α-synucleinopathy as measured by the MDS-UPDRS. For example, the method may increase the time to significant progression of motor symptoms of the disease, as assessed by an increase of at least 5 points from baseline in the MDS-UPDRS Part III score. The MDS-UPDRS (described in more detail in Goetz et al. (2008) Mov. Disord. 23(15):21129-2170) is used to assess various aspects of Parkinson's disease, including non-motor and motor experiences of daily life and motor complications.

[0100] Treatment with an anti-α-synuclein antibody or antigen-binding fragment thereof can improve a subject's cognition. For example, treatment with an anti-α-synuclein antibody or antigen-binding fragment thereof can increase a subject's score on the MoCA. The method can reduce the progression of α-synucleinopathy, as measured by the subject's score on the MoCA.

[0101] Treatment with an anti-alpha-synuclein antibody or antigen-binding fragment thereof (e.g., fixed doses every four weeks for at least one year) may improve gait, balance, and / or Parkinson's disease symptoms compared to a control or reference value, e.g., compared to progression in placebo-treated subjects. The method may reduce the progression of alpha-synucleinopathic disease as measured by gait, balance, and / or Parkinson's disease symptoms.

[0102] Treatment with an anti-α-synuclein antibody or antigen-binding fragment thereof (e.g., a fixed dose every four weeks for at least one year) may improve blood pressure and / or heart rate, as measured, for example, using the orthostatic hypotension questionnaire (OHQ). The method may reduce the progression of α-synucleinopathies, as measured using the OHQ. The OHQ (described in more detail in Kaufmann et al. (2011) Clin. Auton. Res. 22(2):79-90) is used to assess the symptom burden associated with orthostatic hypotension and includes two components: a six-item symptom rating scale and a four-item daily activities scale.

[0103] Treatment with an anti-α-synuclein antibody or antigen-binding fragment thereof (e.g., a fixed dose every 4 weeks for at least 1 year) may be associated with a range of sleep disorders, including, for example, polysomnography with or without video, the Innsbruck REM Sleep Behavior Disorder Questionnaire (described in more detail by Frauscher et al. (2012) Mov. Disord. 27(13), 1673-1678), the REM Behavior Disorder Questionnaire Hong Kong (described in more detail by Shen et al. (2014) Sleep Med. 15(8), 952-958), the CGI (e.g., CGI-C), the PGI (e.g., PGI-I or PGI-C, as described in more detail by Guy (1976) ECDEU assessment manual for psychopharmacology, USDept. of Health, Education, and Welfare), and / or the CIRUS-RBD questionnaire (Gilat et al. (2020) Mov. Disord. 35(2):344-349) The method may improve one or more symptoms of REM behavior disorder as measured using, for example, polysomnography with or without video, the Innsbruck REM Sleep Behavior Questionnaire, the REM Behavior Disorder Questionnaire Hong Kong, the CGI-C, the PGI-I / C, and / or the CIRUS-RBD questionnaire.

[0104] Treatment with an anti-alpha-synuclein antibody or antigen-binding fragment thereof (e.g., a fixed dose every four weeks for at least one year) may reduce plasma neurofilament light chain levels, reduce total alpha-synuclein levels, reduce free unbound CSF alpha-synuclein levels, and / or reduce CSF neurofilament light chain levels. The method may reduce the progression of alpha-synucleinopathies as measured by plasma neurofilament light chain levels, total alpha-synuclein levels, free unbound CSF alpha-synuclein levels, and / or CSF neurofilament light chain levels.

[0105] A reduction in any of the scores or levels described herein can be a reduction compared to a control measurement in the subject (e.g., a baseline score in the subject immediately before treatment was initiated). For example, treatment with an anti-alpha-synuclein antibody or antigen-binding fragment thereof can reduce the score or level by at least 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, or 95% compared to baseline.

[0106] Preferably, any reduction in score or level described herein can be compared to the score or level in a subject or group of subjects not administered the anti-α-synuclein antibody or antigen-binding fragment thereof (e.g., a control subject, a placebo-treated subject, a control group, or a placebo-treated subject group). For example, treatment with an anti-α-synuclein antibody or antigen-binding fragment thereof can provide a reduction in score or level of at least 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, or 95% compared to the corresponding score or level in a control subject, a placebo-treated subject, a control group, or a placebo-treated subject group. Preferably, the comparison is with a placebo-treated subject group, e.g., a typical change or mean change in score obtained from a placebo-treated subject group. Preferably, the control or placebo-treated subject is a subject with the same disease or disorder as the treated subject. Preferably, the control or placebo-treated subject has the same or similar level of disease progression as the treated subject at the start of treatment. Preferably, control or placebo treated subjects have scores in the same range or similar to those of treated subjects at the start of treatment.

[0107] Preferably, the anti-alpha-synuclein antibody or antigen-binding fragment thereof is administered to a subject in a fixed dose, e.g., every four weeks for at least one year, and the method reduces the level of free, unbound alpha-synuclein in the subject's cerebrospinal fluid (CSF). The anti-alpha-synuclein antibody or antigen-binding fragment thereof may be administered to a subject in a fixed dose, e.g., every four weeks for at least one year, and the method may reduce the level of free, unbound alpha-synuclein in the subject's CSF by at least 10%, at least 20%, at least 30%, at least 40%, at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, or at least 95%. The anti-alpha-synuclein antibody or antigen-binding fragment thereof may be administered to a subject in a fixed dose, e.g., every four weeks for at least one year, and the method may reduce the level of free, unbound alpha-synuclein in the subject's CSF by at least 10%, at least 20%, at least 30%, at least 40%, at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, or at least 95% from baseline. Preferably, the anti-alpha-synuclein antibody or antigen-binding fragment thereof may be administered to a subject in a fixed dose, e.g., every four weeks for at least one year, and the method may reduce the level of free, unbound alpha-synuclein in the subject's CSF by at least 30% from baseline. The anti-alpha-synuclein antibody or antigen-binding fragment thereof may be administered to a subject in a fixed dose, e.g., every four weeks for at least one year, and the method may reduce the level of free, unbound alpha-synuclein in the subject's CSF by at least 10%, at least 20%, at least 30%, at least 40%, at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, or at least 95% compared to a control or reference value, e.g., compared to levels in a placebo-treated subject. Preferably, the anti-alpha-synuclein antibody or antigen-binding fragment thereof is administered to a subject in a fixed dose, e.g., every four weeks for at least one year, and the method reduces the level of free, unbound alpha-synuclein in the subject's CSF by at least 30% compared to a control or reference value, e.g., compared to levels in a placebo-treated subject.

[0108] An anti-alpha-synuclein antibody or antigen-binding fragment thereof may be administered to a subject in a fixed dose, for example, every four weeks for at least one year, and the method may reduce the level of free, unbound alpha-synuclein in the subject's interstitial fluid (ISF). An anti-alpha-synuclein antibody or antigen-binding fragment thereof may be administered to a subject in a fixed dose, for example, every four weeks for at least one year, and the method may reduce the level of free, unbound alpha-synuclein in the subject's ISF by at least 10%, at least 20%, at least 30%, at least 40%, at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, or at least 95%. An anti-alpha-synuclein antibody or antigen-binding fragment thereof may be administered to a subject in a fixed dose, for example, every four weeks for at least one year, and the method may reduce the level of free, unbound alpha-synuclein in the subject's ISF by at least 10%, at least 20%, at least 30%, at least 40%, at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, or at least 95% from baseline. An anti-alpha-synuclein antibody or antigen-binding fragment thereof may be administered to a subject in a fixed dose, for example, every four weeks for at least one year, and the method may reduce the level of free, unbound alpha-synuclein in the subject's ISF by at least 30% from baseline. The anti-alpha-synuclein antibody or antigen-binding fragment thereof may be administered to a subject in a fixed dose, e.g., every four weeks for at least one year, and the method may reduce the level of free, unbound alpha-synuclein in the subject's ISF by at least 10%, at least 20%, at least 30%, at least 40%, at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, or at least 95% compared to a control or reference value, e.g., compared to levels in a placebo-treated subject. The anti-alpha-synuclein antibody or antigen-binding fragment thereof may be administered to a subject in a fixed dose, e.g., every four weeks for at least one year, and the method may reduce the level of free, unbound alpha-synuclein in the subject's ISF by at least 30% compared to a control or reference value, e.g., compared to levels in a placebo-treated subject.

[0109] An anti-alpha-synuclein antibody or antigen-binding fragment thereof may be administered to a subject in a fixed dose, for example, every four weeks for at least one year, and the method may reduce alpha-synuclein diffusion in the subject. An anti-alpha-synuclein antibody or antigen-binding fragment thereof may be administered to a subject in a fixed dose, for example, every four weeks for at least one year, and the method may reduce alpha-synuclein diffusion in the subject by at least 10%, at least 20%, at least 30%, at least 40%, at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, or at least 95%. The anti-alpha-synuclein antibody or antigen-binding fragment thereof may be administered to a subject in a fixed dose, for example, every four weeks for at least one year, and the method may reduce alpha-synuclein diffusion in the subject by at least 10%, at least 20%, at least 30%, at least 40%, at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, or at least 95% from baseline. The anti-alpha-synuclein antibody or antigen-binding fragment thereof may be administered to a subject in a fixed dose, for example, every four weeks for at least one year, and the method may reduce alpha-synuclein diffusion in the subject by at least 30% from baseline. The anti-alpha-synuclein antibody or antigen-binding fragment thereof may be administered to a subject in a fixed dose, e.g., every four weeks for at least one year, and the method may reduce alpha-synuclein diffusion in the subject by at least 10%, at least 20%, at least 30%, at least 40%, at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, or at least 95% compared to a control or reference value, e.g., compared to alpha-synuclein diffusion in a placebo-treated subject. The anti-alpha-synuclein antibody or antigen-binding fragment thereof may be administered to a subject in a fixed dose, e.g., every four weeks for at least one year, and the method may reduce alpha-synuclein diffusion in the subject by at least 30% compared to a control or reference value, e.g., compared to alpha-synuclein diffusion in a placebo-treated subject.

[0110] An anti-alpha-synuclein antibody or antigen-binding fragment thereof may be administered to a subject in a fixed dose, for example, every four weeks for at least one year, and the method may reduce the subject's score on a modified version of UMSARS part I. An anti-alpha-synuclein antibody or antigen-binding fragment thereof may be administered to a subject in a fixed dose, for example, every four weeks for at least one year, and the method may reduce the subject's score on a modified version of UMSARS part I by at least 10%, at least 20%, at least 30%, at least 40%, at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, or at least 95%. The anti-alpha-synuclein antibody or antigen-binding fragment thereof may be administered to a subject in a fixed dose, for example, every four weeks for at least one year, and the method may reduce the subject's score on a modified version of UMSARS part I by at least 10%, at least 20%, at least 30%, at least 40%, at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, or at least 95% from baseline. The methods or dosing regimens disclosed herein may reduce a subject's modified UMSARS part I score by at least 30% from baseline. The anti-alpha-synuclein antibody or antigen-binding fragment thereof may be administered to a subject in a fixed dose, e.g., every four weeks for at least one year, and the method may reduce the subject's score on a modified version of UMSARS Part I by at least 10%, at least 20%, at least 30%, at least 40%, at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, or at least 95% compared to a control or reference value, e.g., compared to the score in a placebo-treated subject. The anti-alpha-synuclein antibody or antigen-binding fragment thereof may be administered to a subject in a fixed dose, e.g., every four weeks for at least one year, and the method may reduce the subject's score by at least 30% compared to a control or reference value, e.g., compared to the score in a placebo-treated subject.

[0111] An anti-alpha-synuclein antibody or antigen-binding fragment thereof may be administered to a subject in a fixed dose, for example, every four weeks for at least one year, and the method may reduce the subject's UMSARS total score. An anti-alpha-synuclein antibody or antigen-binding fragment thereof may be administered to a subject in a fixed dose, for example, every four weeks for at least one year, and the method may reduce the subject's UMSARS total score by at least 10%, at least 20%, at least 30%, at least 40%, at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, or at least 95%. The anti-alpha-synuclein antibody or antigen-binding fragment thereof may be administered to a subject in a fixed dose, for example, every four weeks for at least one year, and the method may reduce the subject's UMSARS total score by at least 10%, at least 20%, at least 30%, at least 40%, at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, or at least 95% from baseline. The anti-alpha-synuclein antibody or antigen-binding fragment thereof may be administered to a subject in a fixed dose, for example, every four weeks for at least one year, and the method may reduce the subject's UMSARS total score by at least 30% from baseline. The anti-alpha-synuclein antibody or antigen-binding fragment thereof may be administered to a subject in a fixed dose, e.g., every four weeks for at least one year, and the method may reduce the subject's UMSARS total score by at least 10%, at least 20%, at least 30%, at least 40%, at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, or at least 95% compared to a control or reference value, e.g., compared to the score in a placebo-treated subject. The anti-alpha-synuclein antibody or antigen-binding fragment thereof may be administered to a subject in a fixed dose, e.g., every four weeks for at least one year, and the method may reduce the subject's UMSARS total score by at least 30% compared to a control or reference value, e.g., compared to the score in a placebo-treated subject.

[0112] An anti-alpha-synuclein antibody or antigen-binding fragment thereof may be administered to a subject in a fixed dose, for example, every four weeks for at least one year, and the method may reduce the subject's UMSARS part I score. An anti-alpha-synuclein antibody or antigen-binding fragment thereof may be administered to a subject in a fixed dose, for example, every four weeks for at least one year, and the method may reduce the subject's UMSARS part I score by at least 10%, at least 20%, at least 30%, at least 40%, at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, or at least 95%. The anti-alpha-synuclein antibody or antigen-binding fragment thereof may be administered to a subject in a fixed dose, for example, every four weeks for at least one year, and the method may reduce the subject's UMSARS part I score by at least 10%, at least 20%, at least 30%, at least 40%, at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, or at least 95% from baseline. The anti-alpha-synuclein antibody or antigen-binding fragment thereof may be administered to a subject in a fixed dose, for example, every four weeks for at least one year, and the method may reduce the subject's UMSARS part I score by at least 30% from baseline. The anti-alpha-synuclein antibody or antigen-binding fragment thereof may be administered to a subject in a fixed dose, e.g., every four weeks for at least one year, and the method may reduce the subject's UMSARS part I score by at least 10%, at least 20%, at least 30%, at least 40%, at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, or at least 95% compared to a control or reference value, e.g., compared to the score in a placebo-treated subject. The anti-alpha-synuclein antibody or antigen-binding fragment thereof may be administered to a subject in a fixed dose, e.g., every four weeks for at least one year, and the method may reduce the subject's UMSARS part I score by at least 30% compared to a control or reference value, e.g., compared to the score in a placebo-treated subject.

[0113] An anti-alpha-synuclein antibody or antigen-binding fragment thereof may be administered to a subject in a fixed dose, for example, every four weeks for at least one year, and the method may reduce the subject's UMSARS part II score. An anti-alpha-synuclein antibody or antigen-binding fragment thereof may be administered to a subject in a fixed dose, for example, every four weeks for at least one year, and the method may reduce the subject's UMSARS part II score by at least 10%, at least 20%, at least 30%, at least 40%, at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, or at least 95%. The anti-alpha-synuclein antibody or antigen-binding fragment thereof may be administered to a subject in a fixed dose, for example, every four weeks for at least one year, and the method may reduce the subject's UMSARS part II score by at least 10%, at least 20%, at least 30%, at least 40%, at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, or at least 95% from baseline. The anti-alpha-synuclein antibody or antigen-binding fragment thereof may be administered to a subject in a fixed dose, for example, every four weeks for at least one year, and the method may reduce the subject's UMSARS part II score by at least 30% from baseline. The anti-alpha-synuclein antibody or antigen-binding fragment thereof may be administered to a subject in a fixed dose, e.g., every four weeks for at least one year, and the method may reduce the subject's UMSARS part II score by at least 10%, at least 20%, at least 30%, at least 40%, at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, or at least 95% compared to a control or reference value, e.g., compared to the score in a placebo-treated subject. The anti-alpha-synuclein antibody or antigen-binding fragment thereof may be administered to a subject in a fixed dose, e.g., every four weeks for at least one year, and the method may reduce the subject's UMSARS part II score by at least 30% compared to a control or reference value, e.g., compared to the score in a placebo-treated subject.

[0114] An anti-alpha-synuclein antibody or antigen-binding fragment thereof may be administered to a subject in a fixed dose, for example, every four weeks for at least one year, and the method may reduce the subject's 11-item UMSARS score. An anti-alpha-synuclein antibody or antigen-binding fragment thereof may be administered to a subject in a fixed dose, for example, every four weeks for at least one year, and the method may reduce the subject's 11-item UMSARS score by at least 10%, at least 20%, at least 30%, at least 40%, at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, or at least 95%. The anti-alpha-synuclein antibody or antigen-binding fragment thereof may be administered to a subject in a fixed dose, for example, every four weeks for at least one year, and the method may reduce the subject's 11-item UMSARS score by at least 10%, at least 20%, at least 30%, at least 40%, at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, or at least 95% from baseline. The anti-alpha-synuclein antibody or antigen-binding fragment thereof may be administered to a subject in a fixed dose, for example, every four weeks for at least one year, and the method may reduce the subject's 11-item UMSARS score by at least 10%, at least 20%, or at least 30% from baseline. The anti-alpha-synuclein antibody or antigen-binding fragment thereof may be administered to a subject in a fixed dose, e.g., every four weeks for at least one year, and the method may reduce the subject's 11-item UMSARS score by at least 10%, at least 20%, at least 30%, at least 40%, at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, or at least 95% compared to a control or reference value, e.g., compared to the score in a placebo-treated subject. The anti-alpha-synuclein antibody or antigen-binding fragment thereof may be administered to a subject in a fixed dose, e.g., every four weeks for at least one year, and the method may reduce the subject's 11-item UMSARS score by at least 30% compared to a control or reference value, e.g., compared to the score in a placebo-treated subject.

[0115] An anti-alpha-synuclein antibody or antigen-binding fragment thereof may be administered to a subject in a fixed dose, for example, every four weeks for at least one year, and the method may reduce the subject's CGI-S score. An anti-alpha-synuclein antibody or antigen-binding fragment thereof may be administered to a subject in a fixed dose, for example, every four weeks for at least one year, and the method may reduce the subject's CGI-S score by at least 10%, at least 20%, at least 30%, at least 40%, at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, or at least 95%. The anti-alpha-synuclein antibody or antigen-binding fragment thereof may be administered to a subject in a fixed dose, for example, every four weeks for at least one year, and the method may reduce the subject's CGI-S score by at least 10%, at least 20%, at least 30%, at least 40%, at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, or at least 95% from baseline. The anti-alpha-synuclein antibody or antigen-binding fragment thereof may be administered to a subject in a fixed dose, for example, every four weeks for at least one year, and the method may reduce the subject's CGI-S score by at least 30% from baseline. The anti-alpha-synuclein antibody or antigen-binding fragment thereof may be administered to a subject in a fixed dose, e.g., every four weeks for at least one year, and the method may reduce the subject's CGI-S score by at least 10%, at least 20%, at least 30%, at least 40%, at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, or at least 95% compared to a control or reference value, e.g., compared to the score in a placebo-treated subject. The anti-alpha-synuclein antibody or antigen-binding fragment thereof may be administered to a subject in a fixed dose, e.g., every four weeks for at least one year, and the method may reduce the subject's CGI-S score by at least 30% compared to a control or reference value, e.g., compared to the score in a placebo-treated subject.

[0116] An anti-alpha-synuclein antibody or antigen-binding fragment thereof may be administered to a subject in a fixed dose, for example, every four weeks for at least one year, and the method may reduce the subject's SCOPA-AUT score. An anti-alpha-synuclein antibody or antigen-binding fragment thereof may be administered to a subject in a fixed dose, for example, every four weeks for at least one year, and the method may reduce the subject's SCOPA-AUT score by at least 10%, at least 20%, at least 30%, at least 40%, at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, or at least 95%. The anti-alpha-synuclein antibody or antigen-binding fragment thereof may be administered to a subject in a fixed dose, for example, every four weeks for at least one year, and the method may reduce the subject's SCOPA-AUT score by at least 10%, at least 20%, at least 30%, at least 40%, at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, or at least 95% from baseline. The anti-alpha-synuclein antibody or antigen-binding fragment thereof may be administered to a subject in a fixed dose, for example, every four weeks for at least one year, and the method may reduce the subject's SCOPA-AUT score by at least 30% from baseline. The anti-alpha-synuclein antibody or antigen-binding fragment thereof may be administered to a subject in a fixed dose, for example, every four weeks for at least one year, and the method may reduce the subject's SCOPA-AUT score by at least 10%, at least 20%, at least 30%, at least 40%, at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, or at least 95% compared to a control or reference value, for example, compared to the score in a placebo-treated subject. The anti-alpha-synuclein antibody or antigen-binding fragment thereof may be administered to a subject in a fixed dose, for example, every four weeks for at least one year, and the method may reduce the subject's SCOPA-AUT score by at least 30% compared to a control or reference value, for example, compared to the score in a placebo-treated subject.

[0117] Treatment with an anti-alpha-synuclein antibody or antigen-binding fragment thereof may improve a subject's cognitive, motor, and / or language function. Thus, an anti-alpha-synuclein antibody or antigen-binding fragment thereof may be administered to a subject at a fixed dose, for example, every four weeks for at least one year, and the method may improve the subject's cognitive, motor, and / or language function. The method may reduce the progression of alpha-synucleinopathic disease as measured by the subject's cognitive, motor, and / or language function.

[0118] Treatment with an anti-α-synuclein antibody or antigen-binding fragment thereof can improve autonomic function, such as orthostatic blood pressure and / or orthostatic heart rate. Thus, an anti-α-synuclein antibody or antigen-binding fragment thereof can be administered to a subject at a fixed dose, for example, every four weeks for at least one year, and the method can improve the subject's orthostatic blood pressure and / or orthostatic heart rate. The method can reduce the progression of α-synucleinopathies, as measured by orthostatic blood pressure and / or orthostatic heart rate.

[0119] An anti-alpha-synuclein antibody or antigen-binding fragment thereof may be administered to a subject in a fixed dose, for example, every four weeks for at least one year, and the method may reduce the subject's MDS-UPDRS score. An anti-alpha-synuclein antibody or antigen-binding fragment thereof may be administered to a subject in a fixed dose, for example, every four weeks for at least one year, and the method may reduce the subject's MDS-UPDRS score by at least 10%, at least 20%, at least 30%, at least 40%, at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, or at least 95%. The anti-alpha-synuclein antibody or antigen-binding fragment thereof may be administered to a subject in a fixed dose, for example, every four weeks for at least one year, and the method may reduce the subject's MDS-UPDRS score by at least 10%, at least 20%, at least 30%, at least 40%, at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, or at least 95% from baseline. The anti-alpha-synuclein antibody or antigen-binding fragment thereof may be administered to a subject in a fixed dose, for example, every four weeks for at least one year, and the method may reduce the subject's MDS-UPDRS score by at least 30% from baseline. The anti-alpha-synuclein antibody or antigen-binding fragment thereof may be administered to a subject in a fixed dose, e.g., every four weeks for at least one year, and the method may reduce the subject's MDS-UPDRS score by at least 10%, at least 20%, at least 30%, at least 40%, at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, or at least 95% compared to a control or reference value, e.g., compared to the score in a placebo-treated subject. The anti-alpha-synuclein antibody or antigen-binding fragment thereof may be administered to a subject in a fixed dose, e.g., every four weeks for at least one year, and the method may reduce the subject's MDS-UPDRS score by at least 30% compared to a control or reference value, e.g., compared to the score in a placebo-treated subject.

[0120] An anti-α-synuclein antibody or antigen-binding fragment thereof may be administered to a subject in a fixed dose, for example, every four weeks for at least one year, and the method may increase the subject's MoCA score. An anti-α-synuclein antibody or antigen-binding fragment thereof may be administered to a subject in a fixed dose, for example, every four weeks for at least one year, and the method may increase the subject's MoCA score by at least 10%, at least 20%, at least 30%, at least 40%, at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, or at least 95%. An anti-α-synuclein antibody or antigen-binding fragment thereof may be administered to a subject in a fixed dose, for example, every four weeks for at least one year, and the method may increase the subject's MoCA score by at least 10%, at least 20%, at least 30%, at least 40%, at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, or at least 95% from baseline. An anti-α-synuclein antibody or antigen-binding fragment thereof may be administered to a subject in a fixed dose, e.g., every four weeks for at least one year, and the method may increase the subject's MoCA score by at least 30% from baseline. An anti-α-synuclein antibody or antigen-binding fragment thereof may be administered to a subject in a fixed dose, e.g., every four weeks for at least one year, and the method may increase the subject's MoCA score by at least 10%, at least 20%, at least 30%, at least 40%, at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, or at least 95% compared to a control or reference value, e.g., compared to the score in a placebo-treated subject. An anti-α-synuclein antibody or antigen-binding fragment thereof may be administered to a subject in a fixed dose, e.g., every four weeks for at least one year, and the method may increase the subject's MoCA score by at least 30% compared to a control or reference value, e.g., compared to the score in a placebo-treated subject.

[0121] Prevention or treatment as defined herein or according to the present invention may be applied as a monotherapy, or may involve the administration of other drugs or therapies in addition to the anti-α-synuclein antibody or antigen-binding fragment. The anti-α-synuclein antibody or antigen-binding fragment may be administered in combination with another drug or therapy for the treatment or prevention of α-synucleinopathies. The anti-α-synuclein antibody or antigen-binding fragment may be administered in combination with established drugs or therapies commonly used in the treatment of α-synucleinopathies, such as L-3,4-dihydroxyphenylalanine (L-DOPA), dopamine (receptor) agonists, catechol-O-methyltransferase (COMT) inhibitors, and / or monoamine oxidase type B (MAO-B) inhibitors. Administration of other drugs or therapies can be performed in combination with, as a supplement to, or in conjunction with the antibodies or antigen-binding fragments used in the present invention, and can involve simultaneous, sequential, or separate dosing of the individual components of the treatment. The antibodies or antigen-binding fragments can be provided in the same composition as additional therapeutic agents. The antibodies or antigen-binding fragments can be provided in a different composition from any other therapeutic agents administered as part of the same treatment. The anti-α-synuclein antibodies or antigen-binding fragments can be administered in combination with one or more other anti-α-synuclein antibodies or antigen-binding fragments thereof, for example, one or more other anti-α-synuclein antibodies or antigen-binding fragments thereof, such as those described herein. Each anti-α-synuclein antibody defined herein can be administered at a fixed dose of 50 to 5,000 mg, or at a fixed dose as defined herein. When two or more anti-α-synuclein antibodies defined herein are administered in the methods of the present invention, each administration can be at a fixed dose of 50 to 5,000 mg, or at a fixed dose as defined herein.

[0122] Combination treatment may be carried out in any manner deemed necessary or convenient by those skilled in the art, and for purposes of this specification, no limitations are intended regarding the order, amount, repetition, or relative amounts of compounds used in combination. 4.2 Anti-α-synuclein antibodies or antigen-binding fragments thereof

[0123] The present invention uses anti-α-synuclein antibodies or antigen-binding fragments thereof. For example, in methods of the present invention, anti-α-synuclein antibodies or antigen-binding fragments thereof are administered to treat or prevent α-synucleinopathies. Similarly, the present invention provides anti-α-synuclein antibodies or antigen-binding fragments thereof for use in methods of treating or preventing α-synucleinopathies. Kits and compositions of the present invention comprise anti-α-synuclein antibodies or antigen-binding fragments thereof. In any embodiment of the present invention, the anti-α-synuclein antibody or antigen-binding fragment thereof may be an anti-α-synuclein antibody or antigen-binding fragment thereof as described below.

[0124] As used herein, the term "anti-α-synuclein antibody" refers to an antibody that binds to α-synuclein. An anti-α-synuclein antibody or an antigen-binding fragment thereof may specifically bind to α-synuclein, e.g., it may bind to α-synuclein but not to other related molecules. For example, an anti-α-synuclein antibody or an antigen-binding fragment thereof may bind to α-synuclein but not to β-synuclein or γ-synuclein. An anti-α-synuclein antibody or an antigen-binding fragment thereof may bind to human α-synuclein but not to human β-synuclein or human γ-synuclein. An anti-α-synuclein antibody or an antigen-binding fragment thereof may bind to human, rat, and / or cynomolgus monkey α-synuclein. An anti-α-synuclein antibody or an antigen-binding fragment thereof may bind to human, rat, and cynomolgus monkey α-synuclein. 4.2.1 Amino Acid Sequences of aslo0452ngl-3 and Its Antigen-Binding Fragments

[0125] The anti-α-synuclein antibody or antigen-binding fragment thereof may be antibody aslo0452ngl-3 or an antigen-binding fragment thereof. aslo0452ngl-3 is a human α-synuclein monoclonal antibody (mAb) derived from the parent clone asyn0087 and directed against the C-terminus of human α-synuclein. aslo0452ngl-3 comprises a variable heavy chain region of SEQ ID NO: 14 and a variable light chain region of SEQ ID NO: 19. aslo0452ngl-3 comprises a light chain having the amino acid sequence of SEQ ID NO: 17. As a result of lysine clipping during the manufacturing process, the last lysine of the aslo0452ngl-3 heavy chain may be absent. Therefore, aslo0452ngl-3 may comprise a heavy chain having the amino acid sequence of SEQ ID NO: 12 or SEQ ID NO: 62. Preferably, aslo0452ngl-3 comprises a heavy chain having the amino acid sequence of SEQ ID NO: 12. Aslo0452ngl-3 may comprise a heavy chain having the amino acid sequence of SEQ ID NO: 12 and a light chain having the amino acid sequence of SEQ ID NO: 17. Aslo0452ngl-3 may comprise a heavy chain having the amino acid sequence of SEQ ID NO: 62 and a light chain having the amino acid sequence of SEQ ID NO: 17. Aslo0452ngl-3 binds to both monomeric and aggregated forms of human α-synuclein. Aslo0452ngl-3 has been shown to reduce α-synuclein diffusion in vivo. Furthermore, aslo0452ngl-3 has been shown to bind and reduce free, unbound α-synuclein levels in interstitial fluid (ISF) and cerebrospinal fluid (CSF) in animal models of disease. Aslo0452ngl-3 and its production are described in more detail in WO 2017 / 207739, which is incorporated herein by reference in its entirety. As shown herein, aslo0452ngl-3 is the first anti-α-synuclein antibody shown to reduce free, unbound levels of α-synuclein in the CSF of human subjects, allowing for measurement of target engagement of aslo0452ngl-3 during treatment.

[0126] An anti-alpha-synuclein antibody or antigen-binding fragment thereof for use in the present invention may have the six CDRs of antibody aslo0452ngl-3. Thus, preferably, the anti-alpha-synuclein antibody or antigen-binding fragment thereof comprises: a) (i) H-CDR1 of SEQ ID NO: 5; (ii) H-CDR2 of SEQ ID NO: 15, and (iii) three heavy chain CDRs having the sequence of H-CDR3 of SEQ ID NO: 16; b) (i) L-CDR1 of SEQ ID NO: 20; (ii) L-CDR2 of SEQ ID NO: 10, and (iii) three light chain CDRs having the sequence of L-CDR3 of SEQ ID NO: 21.

[0127] As used herein, "H-CDR" refers to a complementary determining region (CDR) on the heavy chain region of an antibody or antigen-binding fragment thereof, and "L-CDR" refers to a complementary determining region (CDR) on the light chain region of an antibody or antigen-binding fragment thereof.

[0128] The anti-alpha-synuclein antibody or antigen-binding fragment thereof may comprise a variable heavy chain region encoded by a nucleotide sequence having at least 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100% identity to the nucleotide sequence defined by SEQ ID NO: 13, and / or a variable light chain region encoded by a nucleotide sequence having at least 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100% identity to the nucleotide sequence defined by SEQ ID NO: 18.

[0129] The anti-alpha-synuclein antibody or antigen-binding fragment thereof may comprise a variable heavy chain region encoded by the nucleotide sequence defined by SEQ ID NO: 13 and / or a variable light chain region encoded by the nucleotide sequence defined by SEQ ID NO: 18. Preferably, the anti-alpha-synuclein antibody or antigen-binding fragment thereof comprises a variable heavy chain region encoded by the nucleotide sequence defined by SEQ ID NO: 13 and a variable light chain region encoded by the nucleotide sequence defined by SEQ ID NO: 18.

[0130] The anti-alpha-synuclein antibody or antigen-binding fragment thereof may comprise a variable heavy chain region having the amino acid sequence of SEQ ID NO: 14 or having at least 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100% identity to the amino acid sequence defined by SEQ ID NO: 14, and / or a variable light chain region having the amino acid sequence defined by SEQ ID NO: 19 or having at least 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100% identity to the amino acid sequence defined by SEQ ID NO: 19.

[0131] The anti-alpha-synuclein antibody or antigen-binding fragment thereof may comprise a variable heavy chain region having the amino acid sequence of SEQ ID NO: 14 and / or a variable light chain region having the amino acid sequence of SEQ ID NO: 19. Preferably, the anti-alpha-synuclein antibody or antigen-binding fragment thereof comprises a variable heavy chain region having the amino acid sequence of SEQ ID NO: 14 and a variable light chain region having the amino acid sequence of SEQ ID NO: 19. The anti-alpha-synuclein antibody or antigen-binding fragment thereof may comprise a variable heavy chain region consisting of the amino acid sequence defined by SEQ ID NO: 14 and a variable light chain region consisting of the amino acid sequence defined by SEQ ID NO: 19.

[0132] Preferably, the anti-alpha-synuclein antibody or antigen-binding fragment thereof comprises a variable heavy chain region having at least 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100% identity to the sequence defined by SEQ ID NO: 14, and a variable light chain region having at least 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% or 100% identity to the sequence defined by SEQ ID NO: 19, and further comprising: a) (i) H-CDR1 of SEQ ID NO: 5; (ii) H-CDR2 of SEQ ID NO: 15, and (iii) three heavy chain CDRs having the sequence of H-CDR3 of SEQ ID NO: 16; b) (i) L-CDR1 of SEQ ID NO: 20; (ii) L-CDR2 of SEQ ID NO: 10, and (iii) three light chain CDRs having the sequence of L-CDR3 of SEQ ID NO: 21.

[0133] The anti-α-synuclein antibody or antigen-binding fragment thereof may comprise a heavy chain having the amino acid sequence defined by SEQ ID NO: 12 or SEQ ID NO: 62. Preferably, the anti-α-synuclein antibody or antigen-binding fragment thereof comprises a heavy chain having the amino acid sequence defined by SEQ ID NO: 12. The anti-α-synuclein antibody or antigen-binding fragment thereof may comprise a light chain having the amino acid sequence defined by SEQ ID NO: 17. The anti-α-synuclein antibody or antigen-binding fragment thereof may comprise a heavy chain having the amino acid sequence defined by SEQ ID NO: 12 or SEQ ID NO: 62 and / or a light chain having the amino acid sequence defined by SEQ ID NO: 17. Preferably, the anti-α-synuclein antibody or antigen-binding fragment thereof comprises a heavy chain having the amino acid sequence defined by SEQ ID NO: 12 or SEQ ID NO: 62 and a light chain having the amino acid sequence defined by SEQ ID NO: 17. Preferably, the anti-α-synuclein antibody or antigen-binding fragment thereof comprises a heavy chain having the amino acid sequence defined by SEQ ID NO: 12 and a light chain having the amino acid sequence defined by SEQ ID NO: 17. The anti-alpha-synuclein antibody or antigen-binding fragment thereof may comprise a heavy chain consisting of the amino acid sequence defined by SEQ ID NO: 12 or SEQ ID NO: 62, and a light chain consisting of the amino acid sequence defined by SEQ ID NO: 17. The anti-alpha-synuclein antibody or antigen-binding fragment thereof may comprise a heavy chain consisting of the amino acid sequence defined by SEQ ID NO: 12, and a light chain consisting of the amino acid sequence defined by SEQ ID NO: 17. 4.2.2 Amino acid sequences of aslo0543 and its antigen-binding fragments

[0134] The anti-α-synuclein antibody or antigen-binding fragment thereof may be antibody aslo0543, or an antigen-binding fragment thereof. Aslo0543 is a human α-synuclein monoclonal antibody (mAb) derived from the parent clone asyn0087 and directed against the C-terminus of human α-synuclein. Aslo0543 comprises a variable heavy chain region of SEQ ID NO: 24 and a variable light chain region of SEQ ID NO: 30. Aslo0543 comprises a heavy chain (SEQ ID NO: 22) and a light chain (SEQ ID NO: 28). Aslo0543 binds to both monomeric and aggregated forms of human α-synuclein. Aslo0543 and its production are described in more detail in WO 2017 / 207739, incorporated herein by reference in its entirety.

[0135] The anti-alpha-synuclein antibody, or antigen-binding fragment thereof, may have the six CDRs of antibody aslo0543. Thus, the anti-alpha-synuclein antibody, or antigen-binding fragment thereof, may have the six CDRs of antibody aslo0543. a) (i) H-CDR1 of SEQ ID NO: 25; (ii) H-CDR2 of SEQ ID NO: 26, and (iii) three heavy chain CDRs having the sequence of H-CDR3 of SEQ ID NO: 27; b) (i) L-CDR1 of SEQ ID NO: 31; (ii) L-CDR2 of SEQ ID NO: 32, and (iii) three light chain CDRs having the sequence of L-CDR3 of SEQ ID NO: 33.

[0136] The anti-alpha-synuclein antibody or antigen-binding fragment thereof may comprise a variable heavy chain region encoded by a nucleotide sequence having at least 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100% identity to the nucleotide sequence defined by SEQ ID NO:23, and / or a variable light chain region encoded by a nucleotide sequence having at least 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100% identity to the nucleotide sequence defined by SEQ ID NO:29.

[0137] The anti-alpha-synuclein antibody or antigen-binding fragment thereof may comprise a variable heavy chain region encoded by the nucleotide sequence defined by SEQ ID NO: 23 and / or a variable light chain region encoded by the nucleotide sequence defined by SEQ ID NO: 29. Preferably, the anti-alpha-synuclein antibody or antigen-binding fragment thereof comprises a variable heavy chain region encoded by the nucleotide sequence defined by SEQ ID NO: 23 and a variable light chain region encoded by the nucleotide sequence defined by SEQ ID NO: 29.

[0138] The anti-alpha-synuclein antibody or antigen-binding fragment thereof may comprise a variable heavy chain region having the amino acid sequence of SEQ ID NO:24 or having at least 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100% identity to the amino acid sequence defined by SEQ ID NO:24, and / or a variable light chain region having the amino acid sequence defined by SEQ ID NO:30 or having at least 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100% identity to the amino acid sequence defined by SEQ ID NO:30.

[0139] The anti-alpha-synuclein antibody, or antigen-binding fragment thereof, may comprise a variable heavy chain region having the amino acid sequence of SEQ ID NO: 24 and a variable light chain region having the amino acid sequence of SEQ ID NO: 30. Preferably, the anti-alpha-synuclein antibody, or antigen-binding fragment thereof, comprises a variable heavy chain region having the amino acid sequence of SEQ ID NO: 24 and a variable light chain region having the amino acid sequence of SEQ ID NO: 30. The anti-alpha-synuclein antibody, or antigen-binding fragment thereof, may comprise a variable heavy chain region consisting of the amino acid sequence defined by SEQ ID NO: 24 and a variable light chain region consisting of the amino acid sequence defined by SEQ ID NO: 30.

[0140] The anti-alpha-synuclein antibody or antigen-binding fragment thereof may comprise a variable heavy chain region having at least 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100% identity to the sequence defined by SEQ ID NO:24; and a variable light chain region having at least 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% or 100% identity to the sequence defined by SEQ ID NO:30; and a) (i) H-CDR1 of SEQ ID NO: 25; (ii) H-CDR2 of SEQ ID NO: 26, and (iii) three heavy chain CDRs having the sequence of H-CDR3 of SEQ ID NO: 27; b) (i) L-CDR1 of SEQ ID NO: 31; (ii) L-CDR2 of SEQ ID NO: 32, and (iii) three light chain CDRs having the sequence of L-CDR3 of SEQ ID NO: 33.

[0141] The anti-alpha-synuclein antibody or antigen-binding fragment thereof may comprise a variable heavy chain region having at least 80%, 85%, 90% or 95% identity to the sequence defined by SEQ ID NO: 14 and a variable light chain region having at least 80%, 85%, 90% or 92% identity to the sequence defined by SEQ ID NO: 19, and further comprising: a) (i) H-CDR1 of SEQ ID NO: 25; (ii) H-CDR2 of SEQ ID NO: 26, and (iii) three heavy chain CDRs having the sequence of H-CDR3 of SEQ ID NO: 27; b) (i) L-CDR1 of SEQ ID NO: 31; (ii) L-CDR2 of SEQ ID NO: 32, and (iii) three light chain CDRs having the sequence of L-CDR3 of SEQ ID NO: 33.

[0142] The anti-alpha-synuclein antibody or antigen-binding fragment thereof may comprise a variable heavy chain region having at least 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100% identity to the sequence defined by SEQ ID NO:24 and a variable light chain region having at least 80%, 85%, 90%, or 92% identity to the sequence defined by SEQ ID NO:30, and further comprising: a) (i) H-CDR1 of SEQ ID NO: 5; (ii) H-CDR2 of SEQ ID NO: 15, and (iii) three heavy chain CDRs having the sequence of H-CDR3 of SEQ ID NO: 16; b) (i) L-CDR1 of SEQ ID NO: 20; (ii) L-CDR2 of SEQ ID NO: 10, and (iii) three light chain CDRs having the sequence of L-CDR3 of SEQ ID NO: 21.

[0143] The anti-alpha-synuclein antibody or antigen-binding fragment thereof may comprise a heavy chain having the amino acid sequence defined by SEQ ID NO: 22 and / or a light chain having the amino acid sequence defined by SEQ ID NO: 28. The anti-alpha-synuclein antibody or antigen-binding fragment thereof may comprise a heavy chain having the amino acid sequence defined by SEQ ID NO: 22 and a light chain having the amino acid sequence defined by SEQ ID NO: 28. The anti-alpha-synuclein antibody or antigen-binding fragment thereof may comprise a heavy chain consisting of the amino acid sequence defined by SEQ ID NO: 22 and a light chain consisting of the amino acid sequence defined by SEQ ID NO: 28. 4.2.3 Functional Properties of Antibodies and Antigen-Binding Fragments Thereof for Use in the Invention

[0144] Any of the anti-alpha-synuclein antibodies or antigen-binding fragments thereof disclosed herein, e.g., any anti-alpha-synuclein antibody or antigen-binding fragment thereof for use in the present invention, may have any one or more of the functional properties of aslo0452ngl-3, e.g., any of the functional properties of aslo0452ngl-3 described herein. Any of the anti-alpha-synuclein antibodies or antigen-binding fragments thereof disclosed herein, e.g., any anti-alpha-synuclein antibody or antigen-binding fragment thereof for use in the present invention, may have any one or more of the functional properties of aslo0543, e.g., any of the functional properties of aslo0543 described herein.

[0145] Like the parent clone asyn0087, the aslo0452ngl-3 and aslo0543 antibodies bind to the C-terminal region of human α-synuclein (residues 96-140). More specifically, the aslo0452ngl-3 and aslo0543 antibodies bind to a region encompassed by approximately amino acids 102 to 130 of human α-synuclein (e.g., SEQ ID NO: 1). Thus, the present invention may employ anti-α-synuclein antibodies or antigen-binding fragments thereof that specifically bind to the C-terminal region of human α-synuclein. The anti-α-synuclein antibody or antigen-binding fragment thereof may specifically bind to a region encompassing approximately amino acids 102 to 130 of human α-synuclein (e.g., SEQ ID NO: 1), e.g., may specifically bind to the stretch of amino acids 102-130 of human α-synuclein, or may specifically bind to one or more of amino acids 102-130 of human α-synuclein. The anti-α-synuclein antibody or antigen-binding fragment thereof can specifically bind to a region comprising approximately amino acid 120 to approximately amino acid 130 of human α-synuclein (SEQ ID NO: 1). The anti-α-synuclein antibody or antigen-binding fragment thereof may bind to 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, or 29 amino acids in the region including about amino acid 102 to about amino acid 130 of human α-synuclein (SEQ ID NO: 1), such as 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, or 29 of amino acids 102 to 130 of human α-synuclein (SEQ ID NO: 1). The epitope of an anti-α-synuclein antibody or antigen-binding fragment thereof may include amino acids 102 to 130 of human α-synuclein (SEQ ID NO: 1), or may include one or more amino acids from the region including amino acids 102 to 130 of human α-synuclein.For example, the epitope of the anti-α-synuclein antibody or antigen-binding fragment thereof may include 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, or 29 amino acids from amino acids 102 to 130 of human α-synuclein (SEQ ID NO: 1). The anti-α-synuclein antibody or antigen-binding fragment thereof binds to an epitope that is not the same as that bound by the 9E4 antibody.

[0146] The aslo0452ngl-3 and aslo0543 antibodies are selective for α-synuclein. Therefore, preferably, the present invention may use an anti-α-synuclein antibody or antigen-binding fragment thereof that binds to human α-synuclein but not to human β-synuclein or human γ-synuclein. The specificity of an anti-α-synuclein antibody or antigen-binding fragment thereof can be determined by any suitable means, for example, an HTRF epitope competition assay, which measures the binding of biotinylated human α-synuclein to the antibody or its antigen-binding fragment in solution. In an HTRF assay, relevant synucleins (e.g., α-synuclein, β-synuclein, and γ-synuclein) can be titrated into the assay, and the selectivity of the antibody or its antigen-binding fragment can be measured by assessing the degree of inhibition of biotinylated human α-synuclein binding to the antibody or its antigen-binding fragment. IC 50 Values ​​can be determined by curve fitting the data to a four-parameter logistic equation using PRISM 6 software (Graphpad).

[0147] The aslo0452ngl-3 and aslo0543 antibodies bind to human, rat, and cynomolgus monkey alpha-synuclein, respectively. The ability of aslo0452ngl-3 and aslo0543 to bind to human, cynomolgus monkey, and rat alpha-synuclein indicates binding to different epitopes on human alpha-synuclein compared to antibodies that do not bind to human, cynomolgus monkey, and rat alpha-synuclein. Therefore, the aslo0452ngl-3 and aslo0543 antibodies can be used for in vivo safety evaluation and investigation in cynomolgus monkey and rat disease models. Therefore, preferably, the present invention may use an anti-alpha-synuclein antibody or antigen-binding fragment thereof that binds to human, rat, and / or cynomolgus monkey alpha-synuclein. Preferably, the anti-alpha-synuclein antibody or antigen-binding fragment thereof binds to human, rat, and cynomolgus monkey alpha-synuclein. Binding to human, rat, or cynomolgus monkey α-synuclein can be determined by any suitable means, such as an HTRF epitope competition assay. HTRF epitope assays can measure the binding of biotinylated human α-synuclein to the antibody or its antigen-binding fragment. Human, cynomolgus monkey, and rat α-synuclein can be titrated into the assay, and the selectivity of the antibody or its antigen-binding fragment can be assessed by measuring the degree of inhibition of biotinylated human α-synuclein binding to the antibody or its antigen-binding fragment. IC 50 Values ​​are determined, for example, by curve-fitting the data to a four-parameter logistic equation using PRISM 6 software (Graphpad). Species cross-reactivity of antibodies or antigen-binding fragments thereof can be confirmed using a direct-binding HTRF assay format. Antibodies or antigen-binding fragments thereof are titrated into the assay to compete for human, cynomolgus monkey, or rat α-synuclein binding to the antibodies or antigen-binding fragments thereof by HTRF assay.

[0148] The aslo0452ngl-3 and aslo0543 antibodies bind to human α-synuclein with high affinity. The aslo0452ngl-3 and aslo0543 antibodies have K values ​​of 106 pM (95% CI 10-292 pM) and 113 pM (95% CI 5-333 pM), respectively, as measured using Octet analysis. D It has been reported in WO 2017 / 207739 that anti-α-synuclein antibodies or antigen-binding fragments thereof bind to alpha-synuclein with high affinity. Thus, the present invention may use anti-α-synuclein antibodies or antigen-binding fragments thereof that bind to human α-synuclein with high affinity. The anti-α-synuclein antibody or antigen-binding fragment thereof may have a K of less than 500 picomolar (pM), less than 400 pM, less than 300 pM, less than 200 pM, less than 150 pM, less than 120 pM, less than 110 pM, or less than 10 pM, as measured, for example, using Octet analysis. D The affinity of an antibody or antigen-binding fragment thereof can be assessed using an avi-tag α-synuclein-Flag-His tag molecule. The antibody or antigen-binding fragment may be premixed with various concentrations of ligand until equilibrium is reached. The amount of free antibody or antigen-binding fragment thereof can then be measured using an Octet by capturing the free antibody or antigen-binding fragment thereof using biotinylated α-synuclein immobilized on a streptavidin-coated sensor. The amount of free antibody or antigen-binding fragment thereof detected at each α-synuclein concentration can then be calculated using the ligand concentration and the equilibrium dissociation constant (K D The anti-α-synuclein antibody or antigen-binding fragment thereof may have a K of less than 500 picomolar (pM), less than 400 pM, less than 300 pM, less than 200 pM, less than 150 pM, less than 120 pM, less than 110 pM, or less than 10 pM, as measured, for example, using Octet analysis. D Preferably, the anti-α-synuclein antibody or antigen-binding fragment thereof has a K of less than 500 pM, as measured, for example, using Octet analysis. DPreferably, the anti-α-synuclein antibody or antigen-binding fragment thereof has a K of less than 500 picomolar (pM), less than 400 pM, less than 300 pM, less than 200 pM, less than 150 pM, less than 120 pM, less than 110 pM, or less than 10 pM, as measured, for example, using Octet analysis. D Particularly preferably, the anti-α-synuclein antibody or antigen-binding fragment thereof binds to monomeric human alpha-synuclein with a K of less than 500 pM, as measured, for example, using Octet analysis. D It binds to monomeric human alpha-synuclein at

[0149] The aslo0452ngl-3 and aslo0543 antibodies have K values ​​of 74 pM (95% CI 15-177 pM) and 108 pM (95% CI 34-223 pM), respectively, as measured using KinExA analysis. D It has been reported in WO 2017 / 207739 that the aslo0452ngl-3 Fab fragment binds to alpha-synuclein with a K of 174 pM (95% CI 15-177 pM) as measured using KinExA analysis. D It was reported in WO 2017 / 207739 that anti-α-synuclein antibodies or antigen-binding fragments thereof used in the present invention have a K of less than 400 picomolar (pM), less than 300 pM, less than 250 pM, less than 200 pM, less than 150 pM, less than 120 pM, less than 110 pM, less than 100 pM, less than 80 pM, or less than 74 pM, as measured, for example, using KinExA analysis. D The solution-phase affinity (K DThe equilibrium dissociation constant (K) can be assessed using a KinExA instrument (Sapidyne Instruments) with monomeric human biotinylated α-synuclein. Antibodies or antigen-binding fragments thereof may be premixed with various concentrations of each ligand until equilibrium is reached. The amount of free antibody can then be measured using KinExA by capturing the free antibody or antigen-binding fragment thereof using an α-synuclein-coated board, washing away unbound material, and detecting bound antibody using a fluorescently labeled species-specific antibody. The amount of free antibody detected at each α-synuclein concentration is then plotted against the concentration of the ligand, and the KinExA software is used to calculate the equilibrium dissociation constant (K). D The anti-alpha-synuclein antibody or antigen-binding fragment thereof may have a K of less than 400 picomolar (pM), less than 300 pM, less than 250 pM, less than 200 pM, less than 150 pM, less than 120 pM, less than 110 pM, less than 100 pM, less than 80 pM, or less than 74 pM, as measured, for example, using KinExA analysis. D Preferably, the anti-α-synuclein antibody or antigen-binding fragment thereof has a K of less than 400 pM, as measured, for example, using KinExA analysis. D The anti-α-synuclein antibody or antigen-binding fragment thereof may have a K of less than 400 picomolar (pM), less than 300 pM, less than 250 pM, less than 200 pM, less than 150 pM, less than 120 pM, less than 110 pM, less than 100 pM, less than 80 pM, or less than 74 pM, as measured, for example, using KinExA analysis. D Particularly preferably, the anti-α-synuclein antibody or antigen-binding fragment thereof has a K of less than 400 pM, as measured, for example, using KinExA analysis. D It binds to monomeric human alpha-synuclein at

[0150] The aslo0452ngl-3 and aslo0543 antibodies bind to native endogenous human α-synuclein. As used herein, "native endogenous α-synuclein" refers to α-synuclein present in the tissue of a subject being treated. Thus, the present invention may use an anti-α-synuclein antibody or antigen-binding fragment thereof that binds to native endogenous human α-synuclein. Binding of an antibody or antigen-binding fragment thereof to native endogenous human α-synuclein can be determined using any suitable means, for example, by flow cytometry using α-synuclein-positive and -negative cell lines. For example, α-synuclein-positive cells (e.g., SHSY5Y neuroblastoma cells) and α-synuclein-negative cells (e.g., BT-20 breast cancer cells) can be fixed in formaldehyde and permeabilized prior to incubation with an anti-α-synuclein antibody or antigen-binding fragment thereof, a positive control, or an isotype control antibody. The bound antibody can then be detected by incubation with an appropriate secondary antibody. The cells can then be analyzed using a FACS machine, such as a FACS Canto II machine (Becton Dickinson, Franklin Lakes, NJ), and data analysis can be performed using appropriate software, such as FlowJo Software (Tree Star, Ashland, OR). Binding to native endogenous human α-synuclein can be confirmed by a shift in the fluorescent signal in the presence of the antibody or its antigen-binding fragment in α-synuclein-positive cells compared to an isotype control and / or secondary antibody alone, and the absence of a shift in the presence of the antibody or its antigen-binding fragment in α-synuclein-negative cells compared to an isotype control and / or secondary antibody alone. Preferably, the anti-α-synuclein antibody or its antigen-binding fragment binds to native endogenous human α-synuclein in vivo. The ability of an anti-alpha-synuclein antibody, or antigen-binding fragment thereof, to bind to native endogenous human alpha-synuclein in vivo can be determined by administering the antibody, or antigen-binding fragment thereof, to a subject and then determining binding of the antibody, or antigen-binding fragment thereof, to native endogenous alpha-synuclein in a sample obtained from the subject.The anti-alpha-synuclein antibody or antigen-binding fragment thereof may bind to native endogenous human alpha-synuclein in the brain and / or CSF of the subject being treated.

[0151] The aslo0452ngl-3 and aslo0543 antibodies bind to human α-synuclein aggregates. Therefore, the anti-α-synuclein antibodies or antigen-binding fragments thereof used in the present invention can bind to aggregates of human α-synuclein, such as oligomers and / or polymers and / or aggregates of human α-synuclein. The anti-α-synuclein antibodies or antigen-binding fragments thereof used in the present invention can bind to aggregates of human α-synuclein, such as Lewy bodies or Lewy body-like aggregates. The binding of anti-α-synuclein antibodies or antigen-binding fragments thereof to human α-synuclein aggregates can be determined using the DELFIA® antibody capture assay. For example, a mouse IgG1 version of the antibody or antigen-binding fragment thereof can be immobilized on the wells of a 96-well microtiter plate (Nunc). After blocking, aggregated or monomeric human α-synuclein can be incubated in the wells. After washing, the captured human α-synuclein can be detected by adding a human IgG1 TM version of the same antibody or its antigen-binding fragment, followed by an anti-human IgG-Europium conjugate (Perkin Elmer) or an anti-human IgG-HRP conjugate. After incubation and washing, a detection substrate (e.g., TMB or DELFIA enhancer solution) may be added. The plate can then be read in a microtiter plate reader. This assay cannot detect monomeric α-synuclein.

[0152] The aslo0452ngl-3 and aslo0543 antibodies bind to monomeric human α-synuclein. The anti-α-synuclein antibodies or antigen-binding fragments thereof used in the present invention may bind to monomeric human α-synuclein. The anti-α-synuclein antibodies or antigen-binding fragments thereof used in the present invention may bind to monomeric and / or oligomeric human α-synuclein. Binding of the anti-α-synuclein antibodies or antigen-binding fragments thereof to monomeric human α-synuclein may be determined by any suitable means, for example, using a KinExA assay. The anti-α-synuclein antibodies or antigen-binding fragments thereof may bind to monomeric and / or oligomeric α-synuclein in the CSF of a subject. The anti-α-synuclein antibodies or antigen-binding fragments thereof may bind to monomeric α-synuclein in the CSF of a subject. The anti-α-synuclein antibodies or antigen-binding fragments thereof may bind to oligomeric α-synuclein in the CSF of a subject. Binding of an antibody or antigen-binding fragment thereof to monomeric α-synuclein in the subject's CSF can be determined using any suitable means, for example, using an ELISA that specifically detects the presence of monomeric α-synuclein and measures binding of the antibody or antigen-binding fragment thereof to monomeric α-synuclein from the subject's CSF. Binding of an antibody or antigen-binding fragment thereof to oligomeric α-synuclein in the subject's CSF can be determined using any suitable means, for example, using an ELISA that specifically detects the presence of oligomeric α-synuclein and measures binding of the antibody or antigen-binding fragment thereof to oligomeric α-synuclein from the subject's CSF. An anti-α-synuclein antibody or antigen-binding fragment thereof can bind to monomeric and / or oligomeric α-synuclein in the subject's CSF or ISF in vivo. An anti-α-synuclein antibody or antigen-binding fragment thereof can bind to monomeric α-synuclein in the subject's CSF in vivo.

[0153] The aslo0452ngl-3 and aslo0543 antibodies can bind to and sequester both monomeric and aggregated forms of alpha-synuclein. The anti-alpha-synuclein antibodies or antigen-binding fragments thereof used in the present invention can sequester alpha-synuclein. The term "sequester" means binding a molecule in such a way that the molecule is prevented or inhibited from forming aggregates or is prevented or inhibited from forming further aggregates. Antibodies or binding fragments thereof that sequester alpha-synuclein can bind to alpha-synuclein extracellularly, such as in CSF or ISF, and prevent it from entering cells. Antibodies or binding fragments thereof that sequester alpha-synuclein can bind to monomeric alpha-synuclein and prevent it from forming aggregates. Antibodies or binding fragments thereof that sequester alpha-synuclein can bind to alpha-synuclein and prevent it from forming aggregates or prevent it from forming Lewy bodies.

[0154] The anti-α-synuclein antibodies or antigen-binding fragments thereof used in the present invention can bind to both the monomeric and aggregated forms of α-synuclein. The anti-α-synuclein antibodies or antigen-binding fragments thereof can sequester both the monomeric and aggregated forms of α-synuclein. The anti-α-synuclein antibodies or antigen-binding fragments thereof can bind to both the monomeric and aggregated forms of α-synuclein in vivo. The anti-α-synuclein antibodies or antigen-binding fragments thereof can sequester both the monomeric and aggregated forms of α-synuclein in vivo. The ability of the antibodies or antigen-binding fragments thereof to bind to the monomeric and aggregated forms of α-synuclein can be determined using any suitable means, such as by using the KinExA assay and the DELFIA® antibody capture assay, or using any of the methods described herein.

[0155] The aslo0452ngl-3 and aslo0543 antibodies bind to disease-associated pathological forms of α-synuclein, such as Lewy bodies, Lewy neurites, and Lewy microparticles, in Parkinson's disease brain tissue. Thus, preferably, the anti-α-synuclein antibody or antigen-binding fragment thereof binds to disease-associated pathological forms of α-synuclein. This can be assessed by immunohistochemical staining using the antibody or antigen-binding fragment thereof in diseased tissue. For example, immunohistochemical staining of Parkinson's disease brain tissue can show the presence of Lewy bodies, Lewy neurites, neuronal aggregates, Lewy microparticles (dots), and background brain tissue. Minimal staining is observed in normal (non-diseased) brain or tissue that does not contain α-synuclein. Binding to brain tissue can be assessed in vitro or in vivo. Preferably, the anti-alpha-synuclein antibody or antigen-binding fragment thereof binds to the pathological form of alpha-synuclein associated with the disease in vivo, for example in a suitable animal model of an alpha-synucleinopathic disease.

[0156] The aslo0452ngl-3 antibody reduces α-synuclein levels in brain interstitial fluid (ISF). In particular, the aslo0452ngl-3 antibody reduces free, unbound α-synuclein levels in brain interstitial fluid, for example, in an animal model of α-synucleinopathies. An anti-α-synuclein antibody or an antigen-binding fragment thereof can reduce free, unbound α-synuclein levels in brain interstitial fluid. Reduction of free, unbound α-synuclein levels in brain interstitial fluid can be assessed using any suitable means, for example, as described herein above. Thus, an anti-α-synuclein antibody or an antigen-binding fragment thereof can reduce α-synuclein levels in brain interstitial fluid. An anti-α-synuclein antibody or an antigen-binding fragment thereof can reduce free, unbound α-synuclein levels in brain interstitial fluid of an animal, for example, a rat. The anti-alpha-synuclein antibody or antigen-binding fragment thereof may reduce free, unbound alpha-synuclein levels in brain interstitial fluid (e.g., in rats) 1 hour after administration (e.g., intravenous administration). Free, unbound alpha-synuclein levels may be reduced for at least 2, 3, 4, 5, 6, 7, 8, 9, or preferably 10 hours after administration.

[0157] The aslo0452ngl-3 antibody reduces α-synuclein levels in cerebrospinal fluid (CSF). In particular, the aslo0452ngl-3 antibody reduces free, unbound α-synuclein levels in CSF. Thus, an anti-α-synuclein antibody or an antigen-binding fragment thereof can reduce α-synuclein levels in CSF. An anti-α-synuclein antibody or an antigen-binding fragment thereof can reduce free, unbound α-synuclein levels in CSF. The reduction in free, unbound α-synuclein levels in CSF can be assessed using any suitable means, for example, as described herein above. An anti-α-synuclein antibody or an antigen-binding fragment thereof can reduce free, unbound α-synuclein levels in CSF of an animal, e.g., a rat. The anti-alpha-synuclein antibody or antigen-binding fragment thereof may reduce free, unbound alpha-synuclein levels in the CSF (e.g., of a rat) 6 hours after administration (e.g., intravenous administration). Free, unbound alpha-synuclein levels may be reduced for at least 12 hours, 18 hours, 24 hours, 30 hours, 36 hours, 42 hours, 48 ​​hours, 54 hours, 60 hours, 66 hours, or preferably 72 hours.

[0158] The aslo0452ngl-3 antibody reduces α-synuclein diffusion in vivo. This effect of inhibiting α-synuclein diffusion indicates binding to a different epitope on human α-synuclein compared to an antibody that does not inhibit diffusion. Therefore, preferably, the anti-α-synuclein antibody or antigen-binding fragment thereof reduces α-synuclein diffusion in vivo. In vivo reduction of α-synuclein diffusion can be determined using any suitable means, for example, as described herein above. For example, transgenic mice overexpressing α-synuclein (α-syn tg) are injected with a lentiviral vector expressing α-synuclein (LV-α-syn) into the right hippocampus and then immunized with an anti-α-synuclein antibody or antigen-binding fragment thereof, or a control. At the end of the immunization period, mice are euthanized and their brains are fixed. Fixed brains are sectioned and analyzed by immunocytochemistry for levels of α-synuclein immunoreactivity ipsilateral and contralateral to the LV-α-syn injection site. Reduction of α-synuclein diffusion is observed by comparing the level of α-synuclein diffusion from the ipsilateral to the contralateral side of the hippocampus in mice treated with anti-α-synuclein antibodies or antigen-binding fragments thereof with control mice. 4.2.4 Additional Anti-α-Synuclein Antibodies or Antigen-Binding Fragments Thereof

[0159] The anti-α-synuclein antibody or antigen-binding fragment thereof may compete with antibody aslo0452ngl-3 and / or antibody aslo0543 for binding to human α-synuclein. The anti-α-synuclein antibody or antigen-binding fragment thereof may bind to the same epitope on human α-synuclein as antibody aslo0452ngl-3 and / or antibody aslo0543 or an overlapping epitope on human α-synuclein. The anti-α-synuclein antibody or antigen-binding fragment thereof may compete with antibody aslo0452ngl-3 for binding to human α-synuclein. Preferably, the anti-α-synuclein antibody or antigen-binding fragment thereof binds to the same epitope on human α-synuclein as antibody aslo0452ngl-3 or an overlapping epitope on human α-synuclein.

[0160] It is easy to determine whether an antibody or antigen-binding fragment thereof binds to the same or overlapping epitope as a reference antibody or antigen-binding fragment. Such methods are routine in the art. For example, an antibody can be compared to another antibody by a biochemical competition assay, whereby two antibodies (one labeled for detection purposes and one unlabeled) are simultaneously incubated with a given antigen. If a binding signal is achieved with the labeled antibody, the two antibodies are said to recognize distinct, non-overlapping epitopes on the protein of interest. Conversely, if no binding signal is obtained, the binding of one antibody sterically interferes with the binding of the second antibody, and they are characterized as having overlapping epitopes on the protein sequence. Furthermore, the amino acid location of a given epitope can also be identified using modified proteins (e.g., truncated versions, linear peptide sequences derived from the primary amino acid sequence of the antigen, species orthologs) and by proteolytic digestion and mass spectrometry of the antibody bound to the given protein. These methodologies are useful for generating regions of interaction between the antibody and the antigen.

[0161] Further routine experiments (such as peptide mutations and binding analysis) can be performed to confirm whether the observed lack of binding is indeed due to binding of the epitope of the invention or whether it is due to some other phenomenon (such as steric hindrance). Such experiments can be performed using ELISA, RIA, Biacore, flow cytometry, or other known antibody binding assays.

[0162] For example, for fine mapping of specific epitopes, mathematical models of the epitope:paratope interface can be derived from data generated by solving the structure of the antigen:antibody complex using high-resolution imaging methods such as co-crystallization with X-ray diffraction. To confirm the relevance of the derived mathematical model with respect to identifying the critical contact residues that define the epitope, point mutagenesis of the antigen must be subsequently performed and an analysis of the effect of such mutations on the strength of binding between the antigen and the antibody must be established. Using this combination of methods, an accurate map of the critical contact residues that comprise the epitope can be established.

[0163] An antibody or antigen-binding fragment thereof of interest, such as an antibody or antigen-binding fragment thereof that binds to the same epitope as a reference antibody or antigen-binding fragment thereof, can be generated by producing a variant or antigen-binding fragment thereof of the reference antibody. Thus, an antibody or antigen-binding fragment thereof used in the present invention may be a variant or antigen-binding fragment thereof of a known anti-α-synuclein antibody, such as a variant or antigen-binding fragment thereof of aslo0452ngl-3, aslo0543, or asyn0087. Thus, with respect to the variant antibodies or antigen-binding fragments thereof disclosed herein, the reference antibody may be aslo0452ngl-3 or an antigen-binding fragment thereof, aslo0543, or asyn0087 or an antigen-binding fragment thereof.

[0164] Such variant antibodies or antigen-binding fragments thereof may retain one or more CDRs of a reference antibody or antigen-binding fragment thereof, or may have CDRs that share a high level of identity with the CDRs of a reference antibody or antigen-binding fragment thereof. For example, antibodies or antigen-binding fragments for use in the present invention may have one or more CDRs that differ by one or two amino acid residues (e.g., one or two conservative amino acid substitutions) compared to any one or more of the specific CDR sequences mentioned herein (e.g., the CDRs of aslo0452ngl-3, aslo0543, or asyn0087, e.g., any one or more of the CDRs having SEQ ID NOs: 5, 15, 16, 20, 10, and 21, any one or more of the CDRs having SEQ ID NOs: 25, 26, 27, 31, 32, and 33). Antibodies or antigen-binding fragments for use in the present invention may have any set of specific CDR sequences mentioned herein (e.g., aslo0452ngl-3, aslo0543, or asyn0087, e.g., any one or more of the CDRs having SEQ ID NOs: 5, 15, 16, 20, 10, and 21, any one or more of the CDRs having SEQ ID NOs: 25, 26, 27, 31, 32, and 33). The antibody or antigen-binding fragment for use in the present invention may have a set of CDRs that differ by one or two amino acid residues (e.g., one or two conservative amino acid substitutions) compared to the set of CDRs of o0452ngl-3, aslo0543, or asyn0087, for example, the set of CDRs having SEQ ID NOs: 5, 15, 16, 20, 10, and 21, or the set of CDRs having SEQ ID NOs: 25, 26, 27, 31, 32, and 33. The antibody or antigen-binding fragment for use in the present invention may have a set of CDRs that includes one or more of the CDRs set forth in SEQ ID NOs: 5, 6, 7, 9, 10, and 11. The antibody or antigen-binding fragment for use in the present invention may have a set of CDRs set forth in SEQ ID NOs: 5, 6, 7, 9, 10, and 11.

[0165] The anti-alpha-synuclein antibody or antigen-binding fragment thereof may have one or more variations (e.g., one or more conservative amino acid substitutions) in the CDR amino acid sequence that maintains at least 80%, at least 85%, at least 90%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, and up to 99% sequence identity with any one or more of the CDRs of antibody aslo0452ngl-3 (e.g., any one or more of the CDRs having SEQ ID NOs: 5, 15, 16, 20, 10, and 21). Anti-alpha-synuclein antibodies or antigen-binding fragments thereof may have one or more variations in the CDR amino acid sequence that maintain at least 80%, at least 85%, at least 90%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, and up to 99% sequence identity with any one or more of the CDRs of antibody aslo0452ngl-3 (e.g., any one or more of the CDRs having SEQ ID NOs: 5, 15, 16, 20, 10, and 21) and retain binding to alpha-synuclein.

[0166] The anti-alpha-synuclein antibody or antigen-binding fragment thereof may have at least one CDR of a reference antibody. The anti-alpha-synuclein antibody or antigen-binding fragment thereof may have at least one CDR selected from the CDRs of antibody aslo0452ngl-3, i.e., at least one CDR selected from any one of SEQ ID NO:5, SEQ ID NO:15, SEQ ID NO:16, SEQ ID NO:20, SEQ ID NO:10, and SEQ ID NO:21.

[0167] The anti-alpha-synuclein antibody or antigen-binding fragment thereof may have at least one, at least two, at least three, at least four, at least five, or all six of the CDRs of the reference antibody. The anti-alpha-synuclein antibody or antigen-binding fragment thereof may have CDRs selected from the CDRs of antibody aslo0452ngl-3, i.e., at least one, at least two, at least three, at least four, at least five, or all six of SEQ ID NO:5, SEQ ID NO:15, SEQ ID NO:16, SEQ ID NO:20, SEQ ID NO:10, and SEQ ID NO:21.

[0168] The anti-alpha-synuclein antibody, or antigen-binding fragment thereof, may have all six CDRs of the reference antibody. The anti-alpha-synuclein antibody, or antigen-binding fragment thereof, may have all six CDRs of antibody aslo0452ngl-3. The anti-alpha-synuclein antibody, or antigen-binding fragment thereof, may have a set of CDRs in which CDRH1 has the amino acid sequence of SEQ ID NO:5, CDRH2 has the amino acid sequence of SEQ ID NO:15, CDRH3 has the amino acid sequence of SEQ ID NO:16, CDRL1 has the amino acid sequence of SEQ ID NO:20, CDRL2 has the amino acid sequence of SEQ ID NO:10, and CDRL3 has the amino acid sequence of SEQ ID NO:21.

[0169] The CDR3 of the heavy chain of the anti-alpha-synuclein antibody or antigen-binding fragment thereof can be the CDR3 of the heavy chain of the reference antibody, and / or the CDR3 of the light chain of the anti-alpha-synuclein antibody or antigen-binding fragment thereof can be the CDR3 of the light chain of the reference antibody. The CDR3 of the heavy chain of the anti-alpha-synuclein antibody or antigen-binding fragment thereof can be the CDR3 of the heavy chain of antibody aslo0452ngl-3, and / or the CDR3 of the light chain of the anti-alpha-synuclein antibody or antigen-binding fragment thereof can be the CDR3 of the light chain of antibody aslo0452ngl-3. Thus, the CDR3 of the heavy chain of the anti-α-synuclein antibody or antigen-binding fragment thereof can be the CDR3 of SEQ ID NO: 16 of the heavy chain of antibody aslo0452ngl-3, and / or the CDR3 of the light chain of the anti-α-synuclein antibody or antigen-binding fragment thereof can be the CDR3 of SEQ ID NO: 21 of the light chain of antibody aslo0452ngl-3. The CDR3 of the heavy chain of the anti-α-synuclein antibody or antigen-binding fragment thereof can be the CDR3 of the heavy chain of antibody aslo0452ngl-3. The CDR3 of the light chain of the anti-α-synuclein antibody or antigen-binding fragment thereof can be the CDR3 of the light chain of antibody aslo0452ngl-3.

[0170] A variant antibody or antigen-binding fragment thereof may have one or more variations (eg, conservative amino acid substitutions) outside of the CDRs, for example, in one or more of the framework regions.

[0171] A variant antibody or antigen-binding fragment thereof for use in the invention may have a variable heavy chain region (VH) and / or variable light chain region (VL) that share a high level of identity with the VH and VL regions of a reference antibody or antigen-binding fragment thereof. For example, an antibody or antigen-binding fragment for use in the invention may have a VL and / or VL that differs by 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15 or more amino acid residues (e.g., conservative amino acid substitutions) compared to the VH and / or VL of a reference antibody or antigen-binding fragment thereof (e.g., the VH and / or VL of aslo0452ngl-3, aslo0543, or asyn0087, e.g., the VH and / or VL of SEQ ID NOs: 14 and 19, respectively, or the VH and / or VL of SEQ ID NOs: 24 and 30, respectively, or the VH and / or VL of SEQ ID NOs: 2 and 3, respectively). The anti-alpha-synuclein antibody or antigen-binding fragment thereof can comprise a VH and a VL, one or both of which have at least 80%, at least 85%, at least 90%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, and up to 99% sequence identity to the corresponding VH and / or VL of a reference antibody (e.g., the VH and / or VL of aslo0452ngl-3, aslo0543, or asyn0087, e.g., the VH and / or VL of SEQ ID NOs: 14 and 19, respectively, or the VH and / or VL of SEQ ID NOs: 24 and 30, respectively, or the VH and / or VL of SEQ ID NOs: 2 and 3, respectively).

[0172] The differences from the reference VH and / or VL sequences may be outside of the CDRs, i.e., the variant may comprise CDRs from the VH and / or VL of the reference antibody, and the differences from the reference VH and / or VL sequences may be in the framework sequences of the variable domains. The differences from the relevant reference sequences may be located anywhere in the VH and / or VL subsequences, for example, the variant antibody or antigen-binding fragment thereof may contain variations in the CDR sequences, as discussed above.

[0173] Variant antibodies or antigen-binding fragments thereof may be used in the present invention. Such variant antibodies or antigen-binding fragments may retain one or more functional properties of the reference antibody from which they are derived, e.g., any one or more functional properties or characteristics of antibody aslo0542ngl-3 described herein. Variant antibodies or antigen-binding fragments may specifically bind to α-synuclein, e.g., as defined herein. Variant antibodies or antigen-binding fragments may specifically bind to human α-synuclein, e.g., as defined herein. Variant antibodies or antigen-binding fragments may bind to monomeric α-synuclein, e.g., as defined herein. Variant antibodies or antigen-binding fragments may bind to human monomeric α-synuclein, e.g., as defined herein. Variant antibodies or antigen-binding fragments may bind to aggregated α-synuclein, e.g., as defined herein. Variant antibodies or antigen-binding fragments may bind to aggregated human α-synuclein, e.g., as defined herein. A variant antibody or antigen-binding fragment may bind to both monomeric α-synuclein and aggregated α-synuclein, e.g., as defined herein. A variant antibody or antigen-binding fragment may bind to both monomeric human α-synuclein and aggregated human α-synuclein, e.g., as defined herein. A variant antibody or antigen-binding fragment used in the present invention may bind to human α-synuclein, rat α-synuclein, and cynomolgus monkey α-synuclein, e.g., as defined herein. A variant antibody or antigen-binding fragment may bind to the same epitope as a reference antibody or antigen-binding fragment thereof, e.g., as described herein. A variant antibody or antigen-binding fragment thereof may compete with a reference antibody (e.g., aslo0542ngl-3) for binding to human α-synuclein, e.g., as described herein. A variant antibody or antigen-binding fragment may bind to the C-terminal region of human α-synuclein (residues 96-140), e.g., as defined herein. The variant antibody or antigen-binding fragment may, for example, bind to a region encompassed by about amino acid 102 to about amino acid 130 of human alpha-synuclein, as defined herein.

[0174] Conservative amino acid substitutions are particularly contemplated. Conservative substitutions are those that occur within a family of amino acids that have related side chains. Genetically encoded amino acids are generally divided into the following families: (1) acidic: aspartic acid, glutamic acid; (2) basic: lysine, arginine, histidine; (3) nonpolar: alanine, valine, leucine, isoleucine, proline, phenylalanine, methionine, tryptophan; and (4) uncharged polar: glycine, asparagine, glutamine, cysteine, serine, threonine, tyrosine. These families can be further classified: serine and threonine are the aliphatic hydroxy family; asparagine and glutamine are the amide-containing family; alanine, valine, leucine, and isoleucine are the aliphatic family; and phenylalanine, tryptophan, and tyrosine are the aromatic family. Thus, in general, isolated substitutions of leucine with isoleucine or valine, aspartic acid with glutamic acid, threonine with serine, or similar substitutions of amino acids with structurally related amino acids can be expected not to significantly affect the binding function or properties of the resulting antibody, particularly if the substitution does not involve an amino acid within a CDR site.

[0175] The anti-α-synuclein antibody or antigen-binding fragment thereof may be a variant antibody or antigen-binding fragment thereof, wherein the reference antibody is asyn0087 or an antigen-binding fragment thereof comprising a VH of SEQ ID NO: 2 and a VL of SEQ ID NO: 3. In particular, the anti-α-synuclein antibody or antigen-binding fragment thereof may be a variant antibody or antigen-binding fragment thereof, wherein the reference antibody is asyn0087 or an antigen-binding fragment thereof comprising a VH of SEQ ID NO: 2 and a VL of SEQ ID NO: 3, wherein the variant antibody or antigen-binding fragment thereof has a K D and binds to the same epitope as any one of antibodies asyn0087, aslo0452ngl-3, and aslo0543 described herein.

[0176] The anti-alpha-synuclein antibody or antigen-binding fragment thereof may comprise a variable heavy chain region (VH) having the amino acid sequence of SEQ ID NO:2 and a variable light chain region (VL) having the amino acid sequence of SEQ ID NO:3.

[0177] The anti-alpha-synuclein antibody, or antigen-binding fragment thereof, may comprise a variable heavy chain having the sequence defined by SEQ ID NO: 4 and a variable light chain having the sequence defined by SEQ ID NO: 8. The anti-alpha-synuclein antibody, or antigen-binding fragment thereof, may comprise a variable heavy chain having the sequence defined by SEQ ID NO: 4 and a variable light chain having the sequence defined by SEQ ID NO: 8, and has a K of less than 500 pM. D It binds to human α-synuclein at the same epitope as asyn0087, aslo0452ngl-3, or aslo0543.

[0178] The anti-alpha-synuclein antibody or antigen-binding fragment thereof is (i) H-CDR1 of SEQ ID NO: 5; (ii) H-CDR2 of SEQ ID NO: 6; (iii) H-CDR3 of SEQ ID NO: 7; (iv) L-CDR1 of SEQ ID NO: 9; (v) L-CDR2 of SEQ ID NO: 10; (vi) It may comprise at least one CDR selected from L-CDR3 of SEQ ID NO: 11. For example, an anti-α-synuclein antibody or antigen-binding fragment thereof may comprise one, two, three, four, five, or all six of the CDR sequences of SEQ ID NOs: 5, 6, 7, 9, 10, and 11. An anti-α-synuclein antibody or antigen-binding fragment thereof may comprise an H-CDR1 of SEQ ID NO: 5, an H-CDR2 of SEQ ID NO: 6, an H-CDR3 of SEQ ID NO: 7, an L-CDR1 of SEQ ID NO: 9, an L-CDR2 of SEQ ID NO: 10, and an L-CDR3 of SEQ ID NO: 11. An anti-α-synuclein antibody or antigen-binding fragment thereof may comprise an H-CDR3 of SEQ ID NO: 7.

[0179] Framework regions and CDRs or antibodies can be precisely defined (see Kabat et al. (1991) Sequences of Proteins of Immunological Interest, Fifth Edition, US Department of Health and Human Services pp. 91-3242, and Chothia et al. (1987) J. MoI. Biol. 196:901-917, both of which are incorporated herein by reference).

[0180] Minor changes in the amino acid sequence of an anti-α-synuclein antibody or antigen-binding fragment thereof are contemplated as being encompassed by the present invention, provided that the changes in amino acid sequence maintain at least 75%, more preferably at least 80%, at least 90%, at least 95%, and most preferably at least 99% sequence identity with the equivalent sequence of a reference anti-α-synuclein antibody or antigen-binding fragment thereof as defined elsewhere herein. In particular, conservative amino acid substitutions are contemplated.

[0181] The present invention also relates to the use of a single amino acid sequence comprising the light chain of an anti-alpha-synuclein antibody or antigen-binding fragment thereof as defined anywhere herein. The present invention also relates to the use of a single amino acid sequence comprising the heavy chain of an anti-alpha-synuclein antibody or antigen-binding fragment thereof as defined anywhere herein.

[0182] Optimal alignment of sequences for comparison can be achieved, for example, by the Smith and Waterman local homology alignment algorithm (Smith and Waterman (1981) Adv. Appl. Math. 2:484, incorporated herein by reference), by the Needleman and Wunsch algorithm (Needleman and Wunsch (1970) J. Mol. Biol. 48:443, incorporated herein by reference), by the similarity search method of Pearson and Lipman (1988; Proc. Natl. Acad. Sci. USA 85:2444, incorporated herein by reference), or by computer implementations of these algorithms (GAP, BESTFIT, FASTA, and TFASTA—Sequence Analysis Software Package of the Genetics Computer Group, University of Wisconsin Biotechnology Center, 1710 University Avenue, Madison, Wis. 53705) or by visual inspection (see Current Protocols in Molecular Biology, F.M.Ausbel et al., eds., Current Protocols, a joint venture between Greene Publishing Associates, Inc. And John Wiley & Sons, Inc. (1995 Supplement), which is incorporated herein by reference).

[0183] Examples of algorithms that are suitable for determining percent sequence similarity or identity are the BLAST and BLAST 2.0 algorithms (see Altschul et al. (1990) J. Mol. Biol. 215(3):403-410, and http: / / www.ncbi.nlm.nih.gov / of the National Center for Biotechnology Information, both of which are incorporated herein by reference).

[0184] The anti-alpha-synuclein antibody or antigen-binding fragment thereof defined anywhere above may be an IgA, IgD, IgE, IgM, IgG (such as IgG1, IgG2, IgG3 or IgG4) antibody or antigen-binding fragment thereof.

[0185] The anti-α-synuclein antibody or antigen-binding fragment thereof may not have an Fc region. Preferably, the anti-α-synuclein antibody or antigen-binding fragment thereof has an Fc region. The anti-α-synuclein antibody or antigen-binding fragment thereof may have a modified Fc region. Suitable modifications are well known to those skilled in the art and may include, among others, modifications to increase or decrease half-life, remove, reduce or enhance effector function, or provide a substituted cysteine ​​with a free thiol for conjugation. Examples of such modifications are YTE to increase half-life and / or TM to reduce effector function. The anti-α-synuclein antibody or antigen-binding fragment thereof may have reduced binding affinity to IgG Fc receptors. Therefore, the anti-α-synuclein antibody or antigen-binding fragment thereof may have a reduced immunogenic effect. Any of the antibodies or antigen-binding fragments disclosed herein may comprise the mutations M252Y / S254T / T256E (YTE) in the Fc region of the antibody (Dall'Acqua et al. (2006) J. Biol. Chem. 281:23514-23524). Any of the antibodies or antigen-binding fragments disclosed herein may comprise a triple mutation in the Fc region (hereinafter abbreviated as "TM") corresponding to the L234F / L235E / P331S mutations disclosed in Oganesyan et al. (2008) Acta Crystallogr. D. Biol. Crystallogr. 64:700-704. An anti-α-synuclein antibody or antigen-binding fragment thereof may comprise a triple mutation in the Fc region corresponding to L234F / L235E / P331S numbered according to Kabat numbering. The anti-α-synuclein antibody or antigen-binding fragment thereof may be an IgG1 TM antibody or antigen-binding fragment thereof. IgG1 TM is an IgG1 triple mutant containing three point mutations (L234F / L235E / P331S) in the Fc domain, which reduce the binding affinity of the antibody or antigen-binding fragment thereof to Fc-gamma receptors (FcγR) (Oganesyan et al. (2008) Acta Crystallogr. D. Biol. Crystallogr. 64:700-704, incorporated herein by reference).Antibody-mediated prevention of alpha-synuclein spread may not require Fc-related effector functions as a significant mechanism. An anti-α-synuclein antibody or antigen-binding fragment thereof may comprise an Fc region with a YTE mutation. The Fc region may be mutated or replaced with an alternative protein sequence, or the anti-α-synuclein antibody or antigen-binding fragment thereof may be chemically modified to increase its blood-brain barrier permeability.

[0186] The anti-α-synuclein antibody or antigen-binding fragment thereof may be linked to a half-life extender. As used herein, the term "half-life extender" refers to any molecule that, when linked to an anti-α-synuclein antibody or antigen-binding fragment thereof disclosed herein, increases the half-life of the anti-α-synuclein antibody or antigen-binding fragment thereof. Any half-life extender may be linked to the anti-α-synuclein antibody or antigen-binding fragment thereof either covalently or non-covalently. The half-life extender may be polyethylene glycol, a peptide, or human serum albumin.

[0187] The anti-α-synuclein antibody or antigen-binding fragment thereof may be associated with a blood-brain barrier (BBB) ​​permeable molecule. The term "BBB-permeable molecule" refers to any molecule that, when linked to an anti-α-synuclein antibody or antigen-binding fragment thereof disclosed herein, increases the brain penetration ability of the anti-α-synuclein antibody or antigen-binding fragment thereof. For example, a BBB-permeable molecule can be a molecule that specifically binds to one or more species of brain microvascular endothelial cells (BMVECs) and can pass through BMVECs in vitro or in vivo, e.g., from the peripheral vasculature to the CNS vasculature. Whether a molecule is a BBB-permeable molecule can be tested by various in vitro or in vivo assays known to those skilled in the art. For example, transporter molecules can be tested in in vitro transcytosis assays or in vivo assays, such as diuresis assays, as described in U.S. Patent Application No. 62 / 094,503. Other assays that can be used to measure in vivo delivery of a payload across the BBB include, but are not limited to, chronic constriction injury (CCI), spared nerve injury (SNI), or spinal nerve ligation (SNL), all of which can be measured by foot flick or the Hargreaves method (Hargreaves K, et al., Pain; 1988; 32; 77-88). In certain embodiments, the BBB-crossing molecules provided herein can bind to BMVECs from one or more species, e.g., human, cynomolgus monkey, mouse, rat, or bovine BMVECs. Binding can be demonstrated by various methods known to those skilled in the art, for example, in the FMAT assay described in U.S. Patent Application No. 62 / 094,503. In certain embodiments, the BMVECs are brain capillary endothelial cells (BCECs).In certain embodiments, the BBB-permeable molecules provided herein can pass through a monolayer of BCEC in an in vitro transcytosis assay.In certain embodiments, the activity of the BBB-permeable molecules can be demonstrated by visualizing the BBB-permeable molecules in the CNS.For example, tritium-labeled transporter molecules can be delivered to the periphery, for example, intravenously, of a subject, for example, a mouse, and then visualized in the CNS by quantitative whole-body radiography.In certain embodiments, the BBB-permeable molecules are localized in a specific region of the CNS, for example, the cerebellar cortex, cerebral gray matter, spinal gray matter, pons, or a combination thereof.

[0188] The anti-α-synuclein antibody or antigen-binding fragment thereof may be isolated. The anti-α-synuclein antibody or antigen-binding fragment thereof may be purified.

[0189] The anti-α-synuclein antibody or antigen-binding fragment thereof may be a monoclonal antibody. The anti-α-synuclein antibody or antigen-binding fragment thereof may be a humanized antibody. The anti-α-synuclein antibody or antigen-binding fragment thereof may be a human antibody.

[0190] Antigen-binding fragments for use in the present invention include Fab, Fv, scFv, dAb, Fd, Fab', F(ab')2, or isolated complementarity-determining regions (CDRs) with sufficient framework to bind to α-synuclein. Fab fragments can be monovalent fragments consisting of the VL, VH, CL, and CH1 domains. F(ab')2 fragments can be bivalent fragments containing two Fab fragments linked by a disulfide bond at the hinge region. Fc fragments can consist of the CH2 and CH3 domains. Fv fragments can consist of the VL and VH domains of a single antibody arm. dAb fragments (Ward et al. (1989) Nature 341:544-546, incorporated herein by reference) can consist of the VH domain. Isolated complementarity-determining regions (CDRs) with sufficient framework to bind can be the antigen-binding portion of the variable region.

[0191] The antigen-binding portions of the light chain variable region and the antigen-binding portions of the heavy chain variable region, e.g., the two domains of an Fv fragment, VL and VH, can be joined using recombinant methods by a synthetic linker that allows them to be produced as a single protein chain (known as a single chain Fv (scFv), see, e.g., Bird et al. (1988) Science 242(4877):423-426, and Huston et al. (1988) Proc. Natl. Acad. Sci. USA 85:5879-5883, both of which are incorporated herein by reference) in which the VL and VH regions pair to form a monovalent molecule. These are obtained using conventional techniques known to those of skill in the art, and the portions are screened for utility in the same manner as intact antibodies.

[0192] Anti-alpha-synuclein antibodies or antigen-binding fragments thereof for use in the present invention may have any or all of the advantageous properties defined above, or a combination thereof. In particular, anti-alpha-synuclein antibodies or antigen-binding fragments thereof for use in the present invention may be selective for alpha-synuclein and may slow or prevent the intercellular transmission and spread of alpha-synuclein in vivo.

[0193] The functionality of an anti-alpha-synuclein antibody or antigen-binding fragment thereof for use in the present invention, in particular (i) its ability to bind to an epitope on alpha-synuclein, and (ii) its ability to slow or prevent the intercellular transmission and spread of alpha-synuclein in vivo, can be readily determined by assaying its specific activity using the techniques described in WO 2017 / 207739, which is incorporated herein by reference in its entirety. 4.3 Pharmaceutical Compositions and Kits

[0194] The anti-alpha-synuclein antibody or antigen-binding fragment thereof may be provided in a pharmaceutical composition. According to the present invention, the anti-alpha-synuclein antibody or antigen-binding fragment thereof may be administered in the form of a pharmaceutical composition. Suitable pharmaceutical compositions may comprise an anti-alpha-synuclein antibody or antigen-binding fragment thereof as defined anywhere herein, together with a pharmaceutically acceptable excipient.

[0195] The phrase "pharmaceutically acceptable excipient" includes any and all solvents, dispersion media, coatings, antibacterial and antifungal agents, isotonic and absorption delaying agents, and the like, that are compatible with pharmaceutical administration. The compositions may also contain other active compounds that provide complementary, additional, or enhanced therapeutic functions. The pharmaceutical compositions may also be included in a container, pack, or dispenser together with instructions for administration.

[0196] The present invention also relates to a pharmaceutical composition comprising a fixed dose of 50 to 5,000 mg (or any other fixed dose described herein) of an anti-α-synuclein antibody or antigen-binding fragment thereof. The anti-α-synuclein antibody or antigen-binding fragment thereof can be any anti-α-synuclein antibody or antigen-binding fragment thereof as described herein. Accordingly, the present invention provides a pharmaceutical composition comprising a fixed dose of 50 to 5,000 mg (or any other fixed dose described herein) of an anti-α-synuclein antibody or antigen-binding fragment thereof, together with a pharmaceutically acceptable excipient. A suitable pharmaceutically acceptable excipient may facilitate processing of the active compound into a preparation suitable for pharmaceutical administration. The present invention also provides a unit dosage form of a pharmaceutical composition comprising a fixed dose of 50 to 5,000 mg (or any other fixed dose described herein) of an anti-α-synuclein antibody or antigen-binding fragment thereof, together with a pharmaceutically acceptable excipient. The present invention also provides a unit dosage form of 50 to 5,000 mg (or any other fixed dose described herein) of an anti-α-synuclein antibody or antigen-binding fragment thereof. As used herein, "unit dosage form" refers to an amount of a drug, e.g., an anti-α-synuclein antibody or antigen-binding fragment thereof, administered to a subject in a single dose.

[0197] A pharmaceutical composition disclosed herein is formulated to be compatible with its intended route of administration, which may be, for example, intravenous, intraperitoneal, intramuscular, intracavity, subcutaneous, intradermal, or transdermal.

[0198] The present invention also relates to a kit comprising an anti-α-synuclein antibody or antigen-binding fragment thereof (which may be any anti-α-synuclein antibody or antigen-binding fragment thereof as described herein) and, optionally, instructions for its use to treat an α-synucleinopathy at a fixed dose of 50 to 5,000 mg. Preferably, the instructions are for use of the anti-α-synuclein antibody or antigen-binding fragment thereof to treat an α-synucleinopathy at a fixed dose of 50 to 5,000 mg (or any other fixed dose described herein).

[0199] The kit may include 50-5,000 mg (or any other fixed dose as described herein) of an anti-alpha-synuclein antibody or antigen-binding fragment thereof. The anti-alpha-synuclein antibody or antigen-binding fragment thereof may be aslo0452ngl-3.

[0200] The pharmaceutical compositions disclosed herein are not limited to parenteral delivery and may be formulated, for example, for intramuscular, subcutaneous, or intravenous delivery. Compositions suitable for intramuscular, subcutaneous, or intravenous injection include sterile aqueous solutions.

[0201] The pharmaceutical composition can be in the form of an aqueous solution, and can contain physiologically compatible buffers such as Hanks' solution, Ringer's solution, or physiologically buffered saline. The pharmaceutical composition can additionally or alternatively contain substances that increase the viscosity of the suspension, such as sodium carboxymethylcellulose, sorbitol, or dextran. The pharmaceutical composition can be prepared as an appropriate oily injection suspension. Suitable lipophilic solvents or vehicles include fatty oils such as sesame oil, or synthetic fatty acid esters such as ethyl oleate or triglycerides, or liposomes. Optionally, the pharmaceutical composition can contain suitable stabilizers or agents that increase the solubility of the compound, allowing for the preparation of highly concentrated solutions. 4.4 Informal sequence listing

[0202] [Table 2-1]

[0203] [Table 2-2]

[0204] [Table 2-3]

[0205] [Table 2-4]

[0206] [Table 2-5] [Example]

[0207] 5.1 Example 1: Effects of Different Doses of aslo0452ngl-3 in Humans 5.1.1 Example 1.1: Effects of a Single Dose of aslo0452ngl-3 in Healthy Humans

[0208] aslo0452ngl-3 was obtained using the methods described in WO 2017 / 207739(A1), which is incorporated herein by reference in its entirety.

[0209] A randomized, double-blind, placebo-controlled study of single ascending doses (SAD) of aslo0452ng / 3, ranging from 70 mg to 4,500 mg, was designed for healthy human subjects aged 18 to 65 years. SAD cohorts 1–6 included eight subjects each, six in each cohort receiving aslo0452ng / 3 and two in each cohort receiving placebo. A simplified layout of the study design is provided in Figure 1.

[0210] Subjects received either a single intravenous (IV) infusion of aslo0452ngl-3 (70, 210, 400, 1200, 2400, or 4500 mg) or placebo. max Values ​​were generally observed at the end of the 1-hour infusion. Median t max The C was approximately 1 hour after the start of the infusion at the 70, 210, and 2400 mg dose levels, 17 hours at the 400 mg dose level, 5 hours at the 4500 mg dose level, and 9 hours at the 1200 mg dose level. After the end of the intravenous infusion, serum concentrations of aslo0452ngl-3 generally decreased in a multi-step manner. Aslo0452ngl-3 exposure increased dose-dependently across the dose range, as shown in Figure 2. Increasing the aslo0452ngl-3 dose from 1200 to 2400 mg and from 2400 to 4500 mg significantly increased C max and resulted in a greater than dose-proportional increase in AUC∞ (Table 1). Terminal elimination half-lives were comparable across single dose levels (16.6 to 24.3 days).

[0211] [Table 3] %CV: Percentage coefficient of variation, AUC ∞ : Area under the concentration-time curve from time 0 to infinity, C max : maximum observed concentration, PK = pharmacokinetics, t 1 / 2z : Terminal disposition phase half-life.

[0212] Free levels of α-synuclein (αSYN) in cerebrospinal fluid (CSF) were used to determine the pharmacodynamic (PD) effects of the drug. Free αSYN protein was quantified in CSF by Mesoscale Discovery enzyme-linked immunosorbent assay (ELISA) after an immunoprecipitation procedure to remove αSYN bound to aslo0452ngl-3. The percentage of CSF αSYN reduction is summarized for each dose in Table 2 below and is expressed as the mean change from pre-dose baseline.

[0213] [Table 4] %CV: percentage coefficient of variation, CSF: cerebrospinal fluid, SAD: single ascending dose, values ​​in parentheses are standard deviations 5.1.2 Example 1.2: Effect of Multiple Doses of aslo0452ngl-3 in Parkinson's Disease Patients

[0214] A multicenter, randomized, double-blind, placebo-controlled study of multiple ascending doses (MADs) of 1,200 mg, 2,000 mg, or 4,200 mg aslo0452ngl-3 was designed for subjects aged 40 to 85 years with Parkinson's disease (PD). MAD cohorts 1–3 each included 12 subjects, with 9 in each cohort receiving aslo0452ngl-3 and 3 in each cohort receiving placebo. A simplified layout of the study design is provided in Figure 3.

[0215] Subjects in MAD cohorts 1 and 2 received three intravenous infusions of aslo0452ngl-3 or placebo (one infusion on each of days 1, 29, and 57) with 4 weeks between infusions. Cohort 3 (4,200 mg) was not enrolled. After multiple intravenous infusions of 1200 mg of also0452ngl-3, the C of aslo0452ngl-3 max Values ​​were typically observed at the end of the 1-hour infusion, with a median t maxwas approximately 1 hour after the start of the infusion for both the 1200 mg and 2000 mg multiple dose levels. After the end of the intravenous infusion, serum concentrations of aslo0452ngl-3 generally decreased in a multiphase manner. aslo0452ngl-3 exposure increased dose-dependently across the dose range investigated, as shown in Figure 4. All concentration-time profiles from healthy subjects in the SAD study described above were at the lower end of the observed distribution of concentration-time profiles from PD patients, as shown in Figure 5. The terminal elimination half-life was slightly shorter (14.0 days) than in the SAD study. Inter-subject variability, as measured by the geometric mean coefficient of variation percentage (%CV), was low to moderate for AUC (11.3% to 29.8%) and low to high for Cmax (0.2% to 102.8%) across all dose levels in the SAD and MAD studies.

[0216] Free levels of α-SYN in cerebrospinal fluid (CSF) were used to determine drug PD effects. Free α-SYN protein was quantified in CSF by Mesoscale Discovery ELISA after an immunoprecipitation procedure to remove α-SYN bound to aslo0452ngl-3. Multiple intravenous administration of either 1,200 mg or 2,000 mg of aslo0452ngl-3 reduced CSF levels of α-SYN. The mean changes from baseline in CSF free α-SYN levels are shown in Table 3 below. In general, free α-synuclein in CSF was significantly reduced for the aslo0452ngl-3-treated group compared to placebo, and the percentage change in α-synuclein from baseline appeared to be dose-dependent.

[0217] [Table 5]

[0218] aslo0452ngl-3 was safe and well tolerated in the SAD and MAD studies. There were no clinically significant abnormalities / changes in clinical laboratory assessments, vital signs, or ECGs. Positive anti-drug antibody (ADA) results were observed across single dose levels. None of the positive ADA results appeared to impact PK or PD parameters and are not expected to impact safety parameters. 5.1.3 Example 1.3: Effect of Multiple Doses of aslo0452ngl-3 in Patients with Multiple System Atrophy

[0219] Given the surprisingly favorable PK properties, target engagement, and absence of safety issues, a multicenter, randomized, double-blind, placebo-controlled Phase 2 study was designed to test the efficacy, safety, tolerability, PK, and PD of aslo0452ngl-3 administered as multiple intravenous infusions every 4 weeks for 52 weeks in subjects at least 40 years of age with possible or probable multiple system atrophy (MSA).

[0220] The study includes a screening period of up to 42 days (6 weeks), a 52-week double-blind treatment period, and a follow-up safety visit approximately 90 days after the final infusion. Each subject will receive a total of 13 approximately 60-minute IV infusions of aslo0452ngl-3 or placebo during the treatment period, with approximately 4 weeks between infusions, i.e., Q4W dosing. An initial early PK cohort of approximately 15 subjects will be randomized 2:1 to receive either aslo0452ngl-3 or placebo (approximately 10 subjects to aslo0452ngl-3 and 5 subjects to placebo). Dosing of subjects in the early PK cohort will begin with 2400 mg Q4W. After the early PK cohort is fully enrolled, additional subjects will be enrolled in the primary cohort. Subjects in the primary cohort will receive 2000 mg of aslo0452ngl-3 while analysis of PK data from the early PK cohort is ongoing. Depending on PK, safety, immunogenicity, and tolerability data from the early PK cohort, aslo0452ngl-3 dose levels may be adjusted for subjects receiving active treatment.

[0221] The Unified Multiple System Atrophy Rating Scale (UMSARS) will be determined for all subjects. The primary objective is to assess change from baseline in the modified UMSARS Part I at Week 52.

[0222] Secondary purpose:

[0223] Secondary objectives include: a) To evaluate the serum PK and CSF concentrations of aslo0452ngl-3 in subjects with MSA; b) To evaluate the efficacy of aslo0452ngl-3 versus placebo as measured by the change from baseline to week 52 on the 11-item UMSARS specified by Palma et al. (2021); c) To evaluate the efficacy of aslo0452ngl-3 versus placebo as measured by change from baseline to week 52 on the total UMSARS; d) Part II To evaluate the efficacy of aslo0452ngl-3 versus placebo as measured by change from baseline to week 52 on UMSARS; e) To evaluate the efficacy of aslo0452ngl-3 versus placebo as measured by the change from baseline to week 52 on the Clinical Global Impression-Severity (CGI-S) scale; f) To evaluate the efficacy of aslo0452ngl-3 versus placebo on the Scale of Outcome in Parkinson's Disease - Autonomic Dysfunction (SCOPA-AUT), and g) To evaluate the efficacy of aslo0452ngl-3 versus placebo as measured by overall survival at 52 weeks.

[0224] Exploratory purpose:

[0225] Exploratory molecular and imaging biomarker objectives include: a) To evaluate the effect of aslo0452ngl-3 versus placebo on molecular biomarkers as measured by change from baseline to week 52 in plasma and CSF biomarker levels, including but not limited to total αSYN levels and CSF free αSYN levels.

[0226] References Altschul,Stephen F.,et al.'Basic Local Alignment Search Tool'.Journal of Molecular Biology,vol.215,no.3,Oct.1990,pp.403-10.DOI.org(Crossref),https: / / doi.org / 10.1016 / S0022-2836(05)80360-2. Angot,Elodie,and Patrik Brundin.‘Dissecting the Potential Molecular Mechanisms Underlying α-Synuclein Cell-to-Cell Transfer in Parkinson’s Disease’.Parkinsonism&Related Disorders,vol.15,Dec.2009,pp.S143-47.DOI.org(Crossref),https: / / doi.org / 10.1016 / S1353-8020(09)70802-8. Bae,E.J.,et al.‘Antibody-Aided Clearance of Extracellular Alpha-Synuclein Prevents Cell-to-Cell Aggregate Transmission’.Journal of Neuroscience,vol.32,no.39,Sept.2012,pp.13454-69.DOI.org(Crossref),https: / / doi.org / 10.1523 / JNEUROSCI.1292-12.2012. Barone,Daniel A.,and Claire Henchcliffe.‘Rapid Eye Movement Sleep Behavior Disorder and the Link to Alpha-Synucleinopathies’.Clinical Neurophysiology,vol.129,no.8,Aug.2018,pp.1551-64.DOI.org(Crossref),https: / / doi.org / 10.1016 / j.clinph.2018.05.003. Bird,Robert E.,et al.‘Single-Chain Antigen-Binding Proteins’.Science,vol.242,no.4877,Oct.1988,pp.423-26.DOI.org(Crossref),https: / / doi.org / 10.1126 / science.3140379. Bisaglia,Marco,et al.‘Structural Insights on Physiological Functions and Pathological Effects of Alpha-synuclein’.The FASEB Journal,vol.23,no.2,Feb.2009,pp.329-40.DOI.org(Crossref),https: / / doi.org / 10.1096 / fj.08-119784. Busner,Joan,and Steven D.Targum.‘The Clinical Global Impressions Scale:Applying a Research Tool in Clinical Practice’.Psychiatry(Edgmont(Pa.:Township)),vol.4,no.7,July 2007,pp.28-37. Chothia,Cyrus,and Arthur M.Lesk.‘Canonical Structures for the Hypervariable Regions of Immunoglobulins’.Journal of Molecular Biology,vol.196,no.4,Aug.1987,pp.901-17.DOI.org(Crossref),https: / / doi.org / 10.1016 / 0022-2836(87)90412-8. Coon,Elizabeth A.,et al.‘Pure Autonomic Failure’.Mayo Clinic Proceedings,vol.94,no.10,Oct.2019,pp.2087-98.DOI.org(Crossref),https: / / doi.org / 10.1016 / j.mayocp.2019.03.009. Cremades,Nunilo,et al.‘Direct Observation of the Interconversion of Normal and Toxic Forms of α-Synuclein’.Cell,vol.149,no.5,May 2012,pp.1048-59.DOI.org(Crossref),https: / / doi.org / 10.1016 / j.cell.2012.03.037. ‘Current Protocols in Molecular Biology,Edited by M.Ausubel,R.Brent,R.E.Kingston,D.D.Moore,J.G.Seidman,J.A.Smith,and K.Struhl.Volumes 1 and 2.John Wiley&Sons,Inc.,Media,PA,1988,$165.00’.Molecular Reproduction and Development,vol.1,no.2,1989,pp.146-146.DOI.org(Crossref),https: / / doi.org / 10.1002 / mrd.1080010210. Dall’Acqua,William F.,et al.‘Properties of Human IgG1s Engineered for Enhanced Binding to the Neonatal Fc Receptor(FcRn)’.Journal of Biological Chemistry,vol.281,no.33,Aug.2006,pp.23514-24.DOI.org(Crossref),https: / / doi.org / 10.1074 / jbc.M604292200. Danzer,K.M.,et al.‘Different Species of -Synuclein Oligomers Induce Calcium Influx and Seeding’.Journal of Neuroscience,vol.27,no.34,Aug.2007,pp.9220-32.DOI.org(Crossref),https: / / doi.org / 10.1523 / JNEUROSCI.2617-07.2007. Desplats,Paula,et al.‘Inclusion Formation and Neuronal Cell Death through Neuron-to-Neuron Transmission of α-Synuclein’.Proceedings of the National Academy of Sciences,vol.106,no.31,Aug.2009,pp.13010-15.DOI.org(Crossref),https: / / doi.org / 10.1073 / pnas.0903691106. Emmanouilidou,Evangelia,et al.‘Assessment of α-Synuclein Secretion in Mouse and Human Brain Parenchyma’.PLoS ONE,edited by Mark R.Cookson,vol.6,no.7,July 2011,p.e22225.DOI.org(Crossref),https: / / doi.org / 10.1371 / journal.pone.0022225. Fortin,D.L.‘Neural Activity Controls the Synaptic Accumulation of -Synuclein’.Journal of Neuroscience,vol.25,no.47,Nov.2005,pp.10913-21.DOI.org(Crossref),https: / / doi.org / 10.1523 / JNEUROSCI.2922-05.2005. Frauscher,Birgit,et al.‘Validation of the Innsbruck REM Sleep Behavior Disorder Inventory:Validation of the Innsbruck RBD Inventory’.Movement Disorders,vol.27,no.13,Nov.2012,pp.1673-78.DOI.org(Crossref),https: / / doi.org / 10.1002 / mds.25223. Games,D.,et al.‘Reducing C-Terminal-Truncated Alpha-Synuclein by Immunotherapy Attenuates Neurodegeneration and Propagation in Parkinson’s Disease-Like Models’.Journal of Neuroscience,vol.34,no.28,July 2014,pp.9441-54.DOI.org(Crossref),https: / / doi.org / 10.1523 / JNEUROSCI.5314-13.2014. Gilat,Moran,et al.‘Melatonin for Rapid Eye Movement Sleep Behavior Disorder in Parkinson’s Disease:A Randomised Controlled Trial’.Movement Disorders,vol.35,no.2,Feb.2020,pp.344-49.DOI.org(Crossref),https: / / doi.org / 10.1002 / mds.27886. Gilman,S.,et al.‘Second Consensus Statement on the Diagnosis of Multiple System Atrophy’.Neurology,vol.71,no.9,Aug.2008,pp.670-76.DOI.org(Crossref),https: / / doi.org / 10.1212 / 01.wnl.0000324625.00404.15. Goetz,Christopher G.,et al.‘Movement Disorder Society-Sponsored Revision of the Unified Parkinson’s Disease Rating Scale(MDS-UPDRS):Scale Presentation and Clinimetric Testing Results:MDS-UPDRS:Clinimetric Assessment’.Movement Disorders,vol.23,no.15,Nov.2008,pp.2129-70.DOI.org(Crossref),https: / / doi.org / 10.1002 / mds.22340. Guy,W.ECDEU assessment manual for psychopharmacology.1976. Hargreaves,K.,et al.‘A New and Sensitive Method for Measuring Thermal Nociception in Cutaneous Hyperalgesia’.Pain,vol.32,no.1,Jan.1988,pp.77-88.DOI.org(Crossref),https: / / doi.org / 10.1016 / 0304-3959(88)90026-7. Herukka,Sanna-Kaisa,et al.‘Amyloid-β and Tau Dynamics in Human Brain Interstitial Fluid in Patients with Suspected Normal Pressure Hydrocephalus’.Journal of Alzheimer’s Disease,vol.46,no.1,May 2015,pp.261-69.DOI.org(Crossref),https: / / doi.org / 10.3233 / JAD-142862. Huston,J.S.,et al.‘Protein Engineering of Antibody Binding Sites:Recovery of Specific Activity in an Anti-Digoxin Single-Chain Fv Analogue Produced in Escherichia Coli.’Proceedings of the National Academy of Sciences,vol.85,no.16,Aug.1988,pp.5879-83.DOI.org(Crossref),https: / / doi.org / 10.1073 / pnas.85.16.5879. Iwai,Akihiko,et al.‘The Precursor Protein of Non-Aβ Component of Alzheimer’s Disease Amyloid Is a Presynaptic Protein of the Central Nervous System’.Neuron,vol.14,no.2,Feb.1995,pp.467-75.DOI.org(Crossref),https: / / doi.org / 10.1016 / 0896-6273(95)90302-X. Jellinger,Kurt A.‘Neuropathological Spectrum of Synucleinopathies’.Movement Disorders,vol.18,no.S6,Sept.2003,pp.2-12.DOI.org(Crossref),https: / / doi.org / 10.1002 / mds.10557. Kabat.Sequences of Proteins of Immunological Interest.5th ed.,1991. Kalia,Lorraine V.,and Anthony E.Lang.‘Parkinson’s Disease’.The Lancet,vol.386,no.9996,Aug.2015,pp.896-912.DOI.org(Crossref),https: / / doi.org / 10.1016 / S0140-6736(14)61393-3. Kaufmann,Horacio,et al.‘The Orthostatic Hypotension Questionnaire(OHQ):Validation of a Novel Symptom Assessment Scale’.Clinical Autonomic Research,vol.22,no.2,Apr.2012,pp.79-90.DOI.org(Crossref),https: / / doi.org / 10.1007 / s10286-011-0146-2. Lashuel,Hilal A.,et al.‘Amyloid Pores from Pathogenic Mutations’.Nature,vol.418,no.6895,July 2002,pp.291-291.DOI.org(Crossref),https: / / doi.org / 10.1038 / 418291a. Lawand,Nada B.,et al.‘Targeting α-Synuclein as a Therapeutic Strategy for Parkinson’s Disease’.Expert Opinion on Therapeutic Targets,vol.19,no.10,Oct.2015,pp.1351-60.DOI.org(Crossref),https: / / doi.org / 10.1517 / 14728222.2015.1062877. Lee,He-Jin,et al.‘Direct Transfer of α-Synuclein from Neuron to Astroglia Causes Inflammatory Responses in Synucleinopathies’.Journal of Biological Chemistry,vol.285,no.12,Mar.2010,pp.9262-72.DOI.org(Crossref),https: / / doi.org / 10.1074 / jbc.M109.081125. Lee,Seung-Jae,et al.‘Cell-to-Cell Transmission of Non-Prion Protein Aggregates’.Nature Reviews Neurology,vol.6,no.12,Dec.2010,pp.702-06.DOI.org(Crossref),https: / / doi.org / 10.1038 / nrneurol.2010.145. Luk,Kelvin C.,Cheng Song,et al.‘Exogenous α-Synuclein Fibrils Seed the Formation of Lewy Body-like Intracellular Inclusions in Cultured Cells’.Proceedings of the National Academy of Sciences,vol.106,no.47,Nov.2009,pp.20051-56.DOI.org(Crossref),https: / / doi.org / 10.1073 / pnas.0908005106. Luk,Kelvin C.,Victoria M.Kehm,et al.‘Intracerebral Inoculation of Pathological α-Synuclein Initiates a Rapidly Progressive Neurodegenerative α-Synucleinopathy in Mice’.Journal of Experimental Medicine,vol.209,no.5,May 2012,pp.975-86.DOI.org(Crossref),https: / / doi.org / 10.1084 / jem.20112457. Luk,Kelvin C.,Victoria Kehm,et al.‘Pathological α-Synuclein Transmission Initiates Parkinson-like Neurodegeneration in Nontransgenic Mice’.Science,vol.338,no.6109,Nov.2012,pp.949-53.DOI.org(Crossref),https: / / doi.org / 10.1126 / science.1227157. Masliah,Eliezer,et al.‘Passive Immunization Reduces Behavioral and Neuropathological Deficits in an Alpha-Synuclein Transgenic Model of Lewy Body Disease’.PLoS ONE,edited by Grainne M.McAlonan,vol.6,no.4,Apr.2011,p.e19338.DOI.org(Crossref),https: / / doi.org / 10.1371 / journal.pone.0019338. Mollenhauer,Brit,et al.‘α-Synuclein in Human Cerebrospinal Fluid Is Principally Derived from Neurons of the Central Nervous System’.Journal of Neural Transmission,vol.119,no.7,July 2012,pp.739-46.DOI.org(Crossref),https: / / doi.org / 10.1007 / s00702-012-0784-0. Nasreddine,Ziad S.,et al.‘The Montreal Cognitive Assessment,MoCA:A Brief Screening Tool For Mild Cognitive Impairment:MOCA:A BRIEF SCREENING TOOL FOR MCI’.Journal of the American Geriatrics Society,vol.53,no.4,Apr.2005,pp.695-99.DOI.org(Crossref),https: / / doi.org / 10.1111 / j.1532-5415.2005.53221.x. Needleman,Saul B.,and Christian D.Wunsch.‘A General Method Applicable to the Search for Similarities in the Amino Acid Sequence of Two Proteins’.Journal of Molecular Biology,vol.48,no.3,Mar.1970,pp.443-53.DOI.org(Crossref),https: / / doi.org / 10.1016 / 0022-2836(70)90057-4. Oganesyan,Vaheh,et al.‘Structural Characterization of a Human Fc Fragment Engineered for Lack of Effector Functions’.Acta Crystallographica Section D Biological Crystallography,vol.64,no.6,June 2008,pp.700-04.DOI.org(Crossref),https: / / doi.org / 10.1107 / S0907444908007877. Oueslati,Abid,et al.‘Role of Post-Translational Modifications in Modulating the Structure,Function and Toxicity of α-Synuclein’.Progress in Brain Research,vol.183,Elsevier,2010,pp.115-45.DOI.org(Crossref),https: / / doi.org / 10.1016 / S0079-6123(10)83007-9. Palma,Jose-Alberto,et al.‘Limitations of the Unified Multiple System Atrophy Rating Scale as Outcome Measure for Clinical Trials and a Roadmap for Improvement’.Clinical Autonomic Research,vol.31,no.2,Apr.2021,pp.157-64.DOI.org(Crossref),https: / / doi.org / 10.1007 / s10286-021-00782-w. Pearson,W.R.,and D.J.Lipman.‘Improved Tools for Biological Sequence Comparison.’Proceedings of the National Academy of Sciences,vol.85,no.8,Apr.1988,pp.2444-48.DOI.org(Crossref),https: / / doi.org / 10.1073 / pnas.85.8.2444. Recasens,Ariadna,and Benjamin Dehay.‘Alpha-Synuclein Spreading in Parkinson’s Disease’.Frontiers in Neuroanatomy,vol.8,Dec.2014.DOI.org(Crossref),https: / / doi.org / 10.3389 / fnana.2014.00159. Rey,Nolwen L.,et al.‘Transfer of Human α-Synuclein from the Olfactory Bulb to Interconnected Brain Regions in Mice’.Acta Neuropathologica,vol.126,no.4,Oct.2013,pp.555-73.DOI.org(Crossref),https: / / doi.org / 10.1007 / s00401-013-1160-3. Shen,Si-Si,et al.‘Validation Study of REM Sleep Behavior Disorder Questionnaire-Hong Kong(RBDQ-HK)in East China’.Sleep Medicine,vol.15,no.8,Aug.2014,pp.952-58.DOI.org(Crossref),https: / / doi.org / 10.1016 / j.sleep.2014.03.020. Smith,Temple F.,and Michael S.Waterman.‘Comparison of Biosequences’.Advances in Applied Mathematics,vol.2,no.4,Dec.1981,pp.482-89.DOI.org(Crossref),https: / / doi.org / 10.1016 / 0196-8858(81)90046-4. Spillantini,Maria Grazia,and Michel Goedert.‘The α-Synucleinopathies:Parkinson’s Disease,Dementia with Lewy Bodies,and Multiple System Atrophy’.Annals of the New York Academy of Sciences,vol.920,no.1,Jan.2006,pp.16-27.DOI.org(Crossref),https: / / doi.org / 10.1111 / j.1749-6632.2000.tb06900.x. Tran,Hien T.,et al.‘α-Synuclein Immunotherapy Blocks Uptake and Templated Propagation of Misfolded α-Synuclein and Neurodegeneration’.Cell Reports,vol.7,no.6,June 2014,pp.2054-65.DOI.org(Crossref),https: / / doi.org / 10.1016 / j.celrep.2014.05.033. Tsigelny,Igor F.,et al.‘Dynamics of α-Synuclein Aggregation and Inhibition of Pore-like Oligomer Development by β-Synuclein:Modeling of α-Syn Oligomer Formation’.FEBS Journal,vol.274,no.7,Apr.2007,pp.1862-77.DOI.org(Crossref),https: / / doi.org / 10.1111 / j.1742-4658.2007.05733.x. Visser,Martine,et al.‘Assessment of Autonomic Dysfunction in Parkinson’s Disease:The SCOPA-AUT’.Movement Disorders,vol.19,no.11,Nov.2004,pp.1306-12.DOI.org(Crossref),https: / / doi.org / 10.1002 / mds.20153. Volpicelli-Daley,Laura A.,et al.‘Exogenous α-Synuclein Fibrils Induce Lewy Body Pathology Leading to Synaptic Dysfunction and Neuron Death’.Neuron,vol.72,no.1,Oct.2011,pp.57-71.DOI.org(Crossref),https: / / doi.org / 10.1016 / j.neuron.2011.08.033. Ward,E.Sally,et al.‘Binding Activities of a Repertoire of Single Immunoglobulin Variable Domains Secreted from Escherichia Coli’.Nature,vol.341,no.6242,Oct.1989,pp.544-46.DOI.org(Crossref),https: / / doi.org / 10.1038 / 341544a0. Wenning,Gregor K.,et al.‘Development and Validation of the Unified Multiple System Atrophy Rating Scale(UMSARS)’.Movement Disorders,vol.19,no.12,Dec.2004,pp.1391-402.DOI.org(Crossref),https: / / doi.org / 10.1002 / mds.20255. Wenning,Gregor K.,et al.‘The Movement Disorder Society Criteria for the Diagnosis of Multiple System Atrophy’.Movement Disorders,vol.37,no.6,June 2022,pp.1131-48.DOI.org(Crossref),https: / / doi.org / 10.1002 / mds.29005 Winner,Beate,et al.‘In Vivo Demonstration That α-Synuclein Oligomers Are Toxic’.Proceedings of the National Academy of Sciences,vol.108,no.10,Mar.2011,pp.4194-99.DOI.org(Crossref),https: / / doi.org / 10.1073 / pnas.1100976108.

Claims

1. 1. A method for treating or preventing an alpha-synucleinopathy in a subject in need thereof, comprising administering to said subject a fixed dose of 50 to 5,000 mg of an anti-alpha-synuclein antibody or antigen-binding fragment thereof.

2. 2. The method of claim 1, wherein the fixed dose of the anti-alpha-synuclein antibody or antigen-binding fragment thereof is 70 to 4,500 mg.

3. 3. The method of claim 1, wherein the fixed dose of the anti-alpha-synuclein antibody or antigen-binding fragment thereof is 1,000 to 4,500 mg.

4. The method of any one of claims 1 to 3, wherein the fixed dose of the anti-alpha-synuclein antibody or antigen-binding fragment thereof is 1,800 to 2,600 mg.

5. The method of any one of claims 1 to 4, wherein the fixed dose of the anti-alpha-synuclein antibody or antigen-binding fragment thereof is 2,000 to 2,400 mg.

6. The method of any one of claims 1 to 5, wherein the fixed dose of the anti-alpha-synuclein antibody or antigen-binding fragment thereof is 2,000 mg or 2,400 mg.

7. 7. The method of claim 6, wherein the fixed dose of the anti-alpha-synuclein antibody or antigen-binding fragment thereof is 2,000 mg.

8. 7. The method of claim 6, wherein the fixed dose of the anti-alpha-synuclein antibody or antigen-binding fragment thereof is 2,400 mg.

9. the fixed dose of the anti-alpha-synuclein antibody or antigen-binding fragment thereof (a) 1,400 mg, (b) 1,600 mg, (c) 1,700 mg, (d) 1,800 mg, or (e) 4,500 mg.

10. The method of any one of claims 1 to 9, wherein the method comprises administering the anti-alpha-synuclein antibody or antigen-binding fragment thereof intravenously, subcutaneously, intradermally, or intramuscularly.

11. 11. The method of claim 10, wherein the method comprises administering the anti-alpha-synuclein antibody or antigen-binding fragment thereof intravenously.

12. The method of any one of claims 1 to 11, wherein the anti-alpha-synuclein antibody or antigen-binding fragment thereof is administered to the subject once every 3 to 5 weeks.

13. 13. The method of any one of claims 1 to 12, wherein the anti-alpha-synuclein antibody or antigen-binding fragment thereof is administered to the subject multiple times over a period of at least 3 months, 6 months, 9 months, 1 year, 2 years, or 5 years.

14. 14. The method of claim 13, wherein the anti-alpha-synuclein antibody or antigen-binding fragment thereof is administered to the subject once every four weeks for a period of at least three months, at least six months, at least nine months, at least one year, at least two years, or at least five years.

15. 15. The method of any one of claims 1 to 14, wherein the α-synucleinopathies are selected from Parkinson's disease (PD), dementia with Lewy bodies (DLB), multiple system atrophy (MSA), Alzheimer's disease, pure autonomic failure, REM behavior disorder, pro-synucleinopathies, and neuroaxonal dystrophy.

16. The method of claim 15, wherein the α-synucleinopathy is Parkinson's disease.

17. The method of claim 15, wherein the α-synucleinopathy is multiple system atrophy (MSA).

18. The method of claim 15, wherein the α-synucleinopathy is dementia with Lewy bodies (DLB).

19. 16. The method of claim 15, wherein the subject has been diagnosed with possible or probable MSA.

20. 20. The method of any one of claims 1 to 19, wherein the subject being treated has a Unified Multiple System Atrophy Rating Scale (UMSARS) Part I score of 21 or less.

21. the treated subject has a ≥ 18% or greater pulmonary function as measured by the Unified Multiple System Atrophy Rating Scale (UMSARS) Part I score, as determined by the following criteria: a) a severity score of 2 or less for the swallowing item; b) a severity score of 2 or less on the ambulation component, and / or c) have a severity score of 2 or less on the falls item; 21. The method according to any one of claims 1 to 20.

22. 22. The method of any one of claims 1 to 21, wherein the subject being treated has a Unified Multiple System Atrophy Rating Scale (UMSARS) Part IV disability score of 3 or less.

23. 23. The method of any one of claims 1 to 22, wherein the method reduces the progression of the α-synucleinopathy as measured by a modified version of the Unified Multiple System Atrophy Rating Scale (UMSARS) Part I.

24. a) the method reduces the progression of the α-synucleinopathy as measured by the subject's Unified Multiple System Atrophy Rating Scale (UMSARS) total score; b) the method reduces the progression of the α-synucleinopathy as measured by the subject's Unified Multiple System Atrophy Rating Scale (UMSARS) Part I score; c) the method reduces the progression of the α-synucleinopathy as measured by the subject's Unified Multiple System Atrophy Rating Scale (UMSARS) Part II score. d) the method reduces the progression of the α-synucleinopathy as measured by the subject's 11-item Unified Multiple System Atrophy Rating Scale (UMSARS) score; and / or e) The method of any one of claims 1 to 23, wherein said method reduces the progression of said alpha-synucleinopathy as measured by said subject's Clinical Global Impression-Severity (CGI-S) scale score.

25. The method of any one of claims 1 to 24, wherein the method reduces the progression of the α-synucleinopathy as measured by α-synuclein diffusion in the subject.

26. 26. The method of any one of claims 1 to 25, wherein the method reduces the progression of the α-synucleinopathic disease as measured by the level of free, unbound α-synuclein in the cerebrospinal fluid (CSF) of the subject.

27. 27. The method of any one of claims 1 to 26, wherein the method reduces the subject's score on a modified version of the Unified Multiple System Atrophy Rating Scale (UMSARS) Part I.

28. a) the method reduces the subject's Unified Multiple System Atrophy Rating Scale (UMSARS) total score; b) the method reduces the subject's Unified Multiple System Atrophy Rating Scale (UMSARS) Part I score. c) the method reduces the subject's Unified Multiple System Atrophy Rating Scale (UMSARS) Part II score. d) the method reduces the subject's 11-item Unified Multiple System Atrophy Rating Scale (UMSARS) score; and / or e) The method of any one of claims 1 to 27, wherein said method reduces the subject's Clinical Global Impression-Severity (CGI-S) scale score.

29. The method of any one of claims 1 to 28, wherein the method reduces alpha-synuclein diffusion in the subject.

30. 30. The method of any one of claims 1 to 29, wherein the method reduces the level of free, unbound alpha-synuclein in the cerebrospinal fluid (CSF) of the subject.

31. The method of any one of claims 1 to 30, wherein the anti-alpha-synuclein antibody or antigen-binding fragment thereof binds to free, unbound alpha-synuclein in the CSF of the subject.

32. The method of any one of claims 1 to 31, wherein the anti-alpha-synuclein antibody or antigen-binding fragment thereof binds to monomeric and / or oligomeric alpha-synuclein in the CSF of the subject.

33. The method of any one of claims 1 to 32, wherein the anti-alpha-synuclein antibody or antigen-binding fragment thereof binds to alpha-synuclein in the CSF of the subject in vivo.

34. 34. The method of any one of claims 1 to 33, wherein the anti-alpha-synuclein antibody or antigen-binding fragment thereof specifically binds to a region encompassed by about amino acid 102 to about amino acid 130 within the C-terminal region of human alpha-synuclein.

35. The method of any one of claims 1 to 34, wherein the anti-α-synuclein antibody or antigen-binding fragment thereof binds to monomeric and aggregated forms of α-synuclein.

36. 36. The method of claim 35, wherein the anti-alpha-synuclein antibody or antigen-binding fragment thereof binds to monomeric and aggregated forms of alpha-synuclein in vivo.

37. The method of any one of claims 1 to 36, wherein the anti-α-synuclein antibody or antigen-binding fragment thereof sequester both monomeric and aggregated forms of α-synuclein.

38. 38. The method of claim 37, wherein the anti-alpha-synuclein antibody or antigen-binding fragment thereof sequester both monomeric and aggregated forms of alpha-synuclein in vivo.

39. The anti-α-synuclein antibody or antigen-binding fragment thereof has a K Ｄ The method of any one of claims 1 to 38, wherein the antibody binds to monomeric human α-synuclein at

40. 40. The method of any one of claims 1 to 39, wherein the anti-alpha-synuclein antibody or antigen-binding fragment thereof reduces alpha-synuclein diffusion in vivo.

41. the anti-α-synuclein antibody or antigen-binding fragment thereof, a) (i) H-CDR1 of SEQ ID NO: 5; (ii) the H-CDR2 of SEQ ID NO: 15, and (iii) three heavy chain CDRs having the sequence of H-CDR3 of SEQ ID NO: 16; b) (i) L-CDR1 of SEQ ID NO: 20; (ii) the L-CDR2 of SEQ ID NO: 10, and (iii) three light chain CDRs having the sequence of L-CDR3 of SEQ ID NO:

21.

42. The method of claim 41, wherein the anti-alpha-synuclein antibody or antigen-binding fragment thereof comprises a variable heavy chain region comprising an amino acid sequence that is at least 90% identical to the amino acid sequence of SEQ ID NO:

14.

43. The method of claim 41 or 42, wherein the anti-alpha-synuclein antibody or antigen-binding fragment thereof comprises a variable heavy chain region comprising the amino acid sequence of SEQ ID NO:

14.

44. The method of any one of claims 41 to 43, wherein the anti-alpha-synuclein antibody or antigen-binding fragment thereof comprises a variable light chain region comprising an amino acid sequence that is at least 90% identical to the amino acid sequence of SEQ ID NO:

19.

45. The method of any one of claims 41 to 44, wherein the anti-alpha-synuclein antibody or antigen-binding fragment thereof comprises a variable light chain region comprising the amino acid sequence of SEQ ID NO:

19.

46. 42. The method of claim 41, wherein the anti-alpha-synuclein antibody or antigen-binding fragment thereof comprises a variable heavy chain region comprising an amino acid sequence that is at least 95% identical to the amino acid sequence of SEQ ID NO: 14, and a variable light chain region comprising an amino acid sequence that is at least 95% identical to the amino acid sequence of SEQ ID NO:

19.

47. 47. The method of claim 46, wherein the anti-alpha-synuclein antibody or antigen-binding fragment thereof comprises a variable heavy chain region comprising the amino acid sequence of SEQ ID NO: 14 and a variable light chain region comprising the amino acid sequence of SEQ ID NO:

19.

48. The method of claim 41, wherein the anti-alpha-synuclein antibody or antigen-binding fragment thereof comprises a heavy chain comprising an amino acid sequence that is at least 90% identical to the amino acid sequence of SEQ ID NO: 12 or SEQ ID NO:

62.

49. The method of claim 48, wherein the anti-alpha-synuclein antibody or antigen-binding fragment thereof comprises a heavy chain comprising the amino acid sequence of SEQ ID NO: 12 or SEQ ID NO:

62.

50. 50. The method of any one of claims 41, 48, or 49, wherein the anti-alpha-synuclein antibody or antigen-binding fragment thereof comprises a light chain region comprising an amino acid sequence that is at least 90% identical to the amino acid sequence of SEQ ID NO:

17.

51. The method of claim 50, wherein the anti-alpha-synuclein antibody or antigen-binding fragment thereof comprises a light chain region comprising the amino acid sequence of SEQ ID NO:

17.

52. 42. The method of claim 41, wherein the anti-alpha-synuclein antibody or antigen-binding fragment thereof comprises a heavy chain comprising an amino acid sequence that is at least 95% identical to the amino acid sequence of SEQ ID NO: 12 or SEQ ID NO: 62, and a light chain comprising an amino acid sequence that is at least 95% identical to the amino acid sequence of SEQ ID NO:

17.

53. 53. The method of claim 52, wherein the anti-alpha-synuclein antibody or antigen-binding fragment thereof comprises a heavy chain comprising the amino acid sequence of SEQ ID NO: 12 or SEQ ID NO: 62 and a light chain comprising the amino acid sequence of SEQ ID NO:

17.

54. The method of any one of claims 1 to 53, wherein the anti-alpha-synuclein antibody or antigen-binding fragment thereof is an antibody.

55. 55. The method of any one of claims 1 to 54, wherein the anti-alpha-synuclein antibody or antigen binding thereof comprises a triple mutation in the Fc region corresponding to L234F / L235E / P331S numbered according to Kabat numbering.

56. 1. An anti-α-synuclein antibody or antigen-binding fragment thereof for use in a method for treating or preventing an α-synucleinopathy in a subject, the method comprising administering to the subject a fixed dose of 50 to 5,000 mg of the anti-α-synuclein antibody or antigen-binding fragment thereof.

57. A kit comprising: a) an anti-α-synuclein antibody or antigen-binding fragment thereof; b) instructions for its use for treating an α-synucleinopathy at a fixed dose of 50 to 5,000 mg.

Images