A Phase 2 interventional study of ATH434 in Multiple System Atrophy, sponsored by Alterity Therapeutics. Enrolling by invitation at 4 sites in France. Per ClinicalTrials.gov, last updated 2026-10-09.
Sponsored by Alterity Therapeutics · Phase 2, Interventional, and Treatment
This multicenter open-label extension study conducted in France is designed to provide ATH434 orally BID to eligible patients who completed the Phase 2 study ATH434-201, and who may benefit from this treatment according to the evaluation by the Investigator.
This is a multicenter, open-label extension (OLE) study designed to provide continued access to the investigational product ATH434 for eligible participants with Multiple System Atrophy (MSA) who have successfully completed the prior Phase 2 clinical trial (ATH434-201) in France. Up to 5 participants will be enrolled. No new participants will be recruited or enrolled in this study.
The primary objective is to monitor long-term safety, tolerability, and clinical response. Eligible participants will receive ATH434 at a dose of 75 mg twice daily (BID) to be taken with food.
The study is divided into two operational phases:
Initial Treatment Phase: Participants will receive treatment for a planned duration of 12 months.
Extension Phase: Participants may continue treatment beyond the initial 12 months based on the investigator's clinical judgment of ongoing benefit, safety, and tolerability. Continued eligibility will be re-evaluated and documented every 3 months.
Participants will undergo a combination of in-clinic and remote visits to perform safety monitoring, clinical evaluations, and investigational product accountability.
207 studies on the registry are indexed under Multiple System Atrophy; 73 are open to participants now.
This study's planned enrollment of 7 is below the median of 41 across 134 interventional studies indexed under Multiple System Atrophy.
Browse Multiple System Atrophy studies →Alterity Therapeutics is the lead sponsor of 4 studies on the registry; 2 are open to participants now.
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Exclusion Criteria:
Participants who completed the prior ATH434-201 Phase 2 trial will receive ATH434 75 mg orally twice daily (BID). Treatment consists of an initial 12-month treatment phase, followed by an ongoing extension phase based on investigator assessment of continued clinical benefit, safety, and tolerability
Drug: ATH434
ATH434 75 mg tablets administered orally twice daily (BID).
Also known as: PBT434
Incidence, Severity, and Relationship of Adverse Events (AEs) and Serious Adverse Events (SAEs)
All AEs will be reviewed at every participant contact and documented in the CRF. All SAEs will be reported within 24 hours of awareness in accordance with local regulatory requirements.
Time frame: Baseline to completion of study treatment, an average of 1 year.
Change From Baseline in Clinical Laboratory Parameters
Clinical laboratory parameters include hematology and blood chemistry panels.
Time frame: Baseline to completion of study treatment, an average of 1 year.
Change From Baseline in Vital Signs
Vital signs include blood pressure, pulse, temperature, and respiration rate.
Time frame: Baseline to completion of study treatment, an average of 1 year.
Duration of Exposure to ATH434
Total duration of treatment with investigational product per participant.
Time frame: Baseline to completion of study treatment, an average of 1 year.
Cumulative Dose of ATH434
Total cumulative dose of investigational product administered per participant.
Time frame: Baseline to completion of study treatment, an average of 1 year.
Plan to share: No
No publications or documents are linked to this record.
Started Oct 2026 (actual). Primary completion is estimated for Jul 2029, 33 months after the start.
Of 19 phase 2 interventional studies under Multiple System Atrophy, half reached primary completion within 23 months of starting (the median), counting those still running; a quarter within 16 and three quarters within 32. This study's planned 33 months is above that.
How these figures are worked out, and which studies are left out of them.
From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗
Eligibility is decided by the study team. Share this record with your doctor or contact the team directly.
No contact was published for this record. The registry link below has the sponsor’s details.
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Studies of the drug tested here: ATH434
Alterity Therapeutics