Alterity Therapeutics secures FDA alignment on its Phase 3 program for ATH434 in Multiple System Atrophy (MSA), advancing toward registrational development with Fast Track and Orphan Drug Designations.
Written By: Kirti Kumbhar, M. Pharm (QA)
Reviewed By: Pharmacally Editorial Team
Alterity Therapeutics has secured U.S. Food and Drug Administration (FDA) agreement on the design of its registrational Phase 3 program for ATH434 in Multiple System Atrophy (MSA), providing a clear pathway toward a potential New Drug Application (NDA).
The alignment, reached during a successful End-of-Phase 2 meeting, covers the study population, dosing regimen, treatment duration, efficacy endpoints, statistical analysis plan, and safety database requirements. The FDA also endorsed ATH434 50 mg twice daily as the Phase 3 dose. ATH434 has received Fast Track and Orphan Drug Designations from the FDA and Orphan Drug Designation from the European Commission.
Mechanism and Disease Background
ATH434 is an oral small molecule that restores iron balance in the brain, reducing oxidative stress and α-synuclein aggregation, a key feature of MSA pathology.
MSA is a rare, rapidly progressive neurodegenerative disorder characterized by autonomic dysfunction, impaired movement, and loss of balance. The disease affects up to 50,000 people in the United States and currently has no approved therapies that slow progression.
Phase 2 Evidence
The FDA’s decision was supported by findings from the randomized, double-blind, placebo-controlled ATH434-201 Phase 2 trial (NCT05109091), which enrolled 77 adults with MSA. Participants received ATH434 50 mg twice daily, ATH434 75 mg twice daily, or placebo for 12 months.
The 50 mg dose achieved clinically and statistically significant efficacy on the modified 11-item Unified Multiple System Atrophy Rating Scale (UMSARS) Part I, demonstrating a 48% slowing of disease progression compared with placebo. Additional assessments showed improvements in swallowing function, orthostatic hypotension symptoms, and overall disease severity.
Wearable sensor data indicated less decline in outpatient activity levels among treated patients, while biomarker analyses demonstrated reduced iron accumulation in MSA-affected brain regions and trends toward preservation of brain volume. ATH434 was generally well tolerated, with adverse event rates similar to placebo and no treatment-related serious adverse events.
Alterity also reported positive findings from a separate Phase 2 open-label biomarker study in patients with more advanced MSA, further supporting ATH434’s biological activity.
Phase 3 Design
The pivotal Phase 3 study will enroll approximately 200 participants with clinical and biomarker evidence of MSA. Patients will be randomized 1:1 to receive ATH434 50 mg twice daily or placebo for 12 months.
The primary endpoint will be the 11-item UMSARS Part I scale. Key secondary endpoints include the Swallowing Disturbance Questionnaire, Orthostatic Hypotension Symptom Assessment, and Clinical Global Impression of Severity.
Management Perspective and Outlook
Chief Executive Officer David Stamler, M.D., said the FDA’s agreement establishes a well-defined registrational pathway for ATH434 and supports advancement into late-stage development.
Alterity expects to initiate Phase 3 trial activities by the end of 2026. If the study confirms the efficacy and safety observed in Phase 2, ATH434 could become one of the first therapies to modify disease progression in patients with MSA.
Reference
ASX:ATH – Alterity and FDA Agree on Phase 3 Program for ATH434 in MSA
About the Writer
Kirti Kumbhar (LinkedIn) is an M.Pharm graduate with experience in Quality Assurance at Lupin Limited and a strong interest in clinical research, regulatory affairs, and Trial Master File (TMF) management. She has developed knowledge of regulatory documentation, quality systems, compliance, and healthcare research through her professional experience. Passionate about clinical development and continuous learning, Kirti is committed to supporting high-quality healthcare documentation, regulatory excellence, and research-driven healthcare advancements.