Phase 2
Completed N=158
A Study of TAK-341 in Treatment of Multiple System Atrophy
Source: ClinicalTrials.gov NCT05526391 ↗Enrolled (actual)
158
Serious AEs
32.5%
Results posted
Jun 2026
Primary outcomePrimary: Change From Baseline in Modified Unified Multiple System Atrophy Rating Scale (UMSARS) Part I Total Score at Week 52 — 5.58; 5.54 score on a scale — p==0.961
Summary
The main aim is to see how TAK-341 works after 52 weeks in participants with multiple system atrophy as measured by the Unified Multiple System Atrophy Rating Scale Part I (UMSARS).
The study will enroll approximately 138 patients. Participants will receive a total of 13 intravenous infusions every 4 weeks approximately, these may be either of TAK-341 or placebo, after each infusion some blood samplings will be taken and other assessments completed.
This trial will be conducted in North America, Europe and Asia.
Outcome Measures
| Outcome | Result | p-value |
|---|---|---|
| PRIMARY Change From Baseline in Modified Unified Multiple System Atrophy Rating Scale (UMSARS) Part I Total Score at Week 52 |
5.58; 5.54 | =0.961 |
| SECONDARY Change From Baseline in 11-item UMSARS at Week 52 |
7.77; 6.58 | =0.241 |
| SECONDARY Change From Baseline in the UMSARS Total Score (UMSARS Part I + Part II) at Week 52 |
14.38; 12.57 | =0.322 |
| SECONDARY Change From Baseline in UMSARS Part I 11-Item Score at Week 52 |
6.37; 5.66 | =0.446 |
| SECONDARY Change From Baseline in UMSARS Part II at Week 52 |
6.96; 6.37 | =0.557 |
| SECONDARY Change From Baseline on Clinical Global Impression-Severity (CGI-S) Score |
0.41; 0.60; 0.83; 0.86 | =0.121 |
| SECONDARY Change From Baseline in Scales for Outcomes in Parkinson's Disease - Autonomic Dysfunction (SCOPA-AUT) Total Score |
2.24; 2.13; 4.66; 1.88 | =0.924 |
| SECONDARY Overall Survival (OS) at Week 52 |
0.955; 0.936 | =0.626 |
| SECONDARY Change From Baseline in Cerebrospinal Fluid (CSF) Free Alpha-Synuclein (αSYN) |
519.2; 427.2; -76.1; -185.0 | — |
| SECONDARY Maximum Observed Steady State Serum Concentration (Cmax) for TAK-341 |
715.5 | — |
| SECONDARY Time to Maximum Steady State Concentration (Tmax) for TAK-341 |
0.048 | — |
| SECONDARY Area Under the Serum Concentration Time Curve (AUCτ) at Steady State for TAK-341 |
4100.4 | — |
| SECONDARY CSF Concentration of TAK-341 |
0.2855; 665.3636; 616.5000 | — |
| SECONDARY Number of Participants With at Least One Adverse Event (AE) |
71; 73 | — |
| SECONDARY Number of Participants With Anti-Drug Antibodies |
1; 0 | — |
Eligibility Criteria
Inclusion criteria
Diagnostic:
- The participant has a diagnosis of possible or probable MSA using the modified Gilman et al, 2008 diagnostic criteria.
- The participant's onset of first MSA symptoms occurred ≤4 years before screening, as assessed by the investigator.
- Evidence of MSA specific symptoms and deficits as measured by the UMSARS scale.
Exclusion criteria
Medical History:
- The participant has any contraindication to study procedures.
Diagnostic Assessments:
- Presence of confounding diagnosis and/or conditions that could affect participant's safety during the study per investigator judgement.
- The participant's participation in a previous study of a disease-modifying therapy (with proven receipt of active treatment) will compromise the interpretability of the data from the present study, per consultation with medical monitor or designee.
Other:
- The participant has participated in another study investigating active or passive immunization against α-synuclein (αSYN) for progressive disease (PD) or MSA, or has had immunoglobulin G therapy, within 6 months before screening.
Data sourced from ClinicalTrials.gov (NCT05526391). Outcome figures and adverse-event rates are extracted automatically from the registry's posted results and are provided for clinician reference, not as a substitute for the primary publication. Informational only — not medical advice.