FDA Confirms Phase 3 Path for Alterity’s ATH434 in Multiple System Atrophy, Supports Single Pivotal Trial for Potential Approval

Alterity Therapeutics has received the official minutes from its End-of-Phase 2 (EOP2) meeting with the U.S. Food and Drug Administration (FDA), confirming the regulatory framework for the Phase 3 development of ATH434 in multiple system atrophy (MSA). The minutes reinforce the agency’s earlier feedback that a single pivotal Phase 3 trial, supported by confirmatory evidence, could provide the basis for a future New Drug Application (NDA).

The company remains on schedule to begin Phase 3 trial activities by the end of 2026 following finalization of the study protocol.

The FDA agreed with the proposed Phase 3 design, including the study population, treatment regimen, primary efficacy endpoint, and key secondary outcome measures. The agency also considered the anticipated safety database at the completion of the trial to be appropriate for the planned development program.

ATH434 targets iron dysregulation in neurodegeneration

ATH434 is an oral small-molecule iron chaperone that restores normal iron balance in the brain. Excess iron accumulation contributes to abnormal aggregation of α-synuclein, a pathological hallmark of MSA and several Parkinsonian disorders.

Preclinical studies showed that ATH434 reduced α-synuclein pathology while preserving neuronal function. The therapy has received Fast Track Designation from the FDA and Orphan Drug Designation from both the FDA and the European Commission for the treatment of MSA.

MSA is a rare, progressive neurodegenerative disorder characterized by autonomic dysfunction, impaired movement, balance disturbances, and rapid functional decline. No approved therapy currently slows disease progression.

Phase 3 study to enroll approximately 200 patients

The registrational Phase 3 trial is expected to enroll approximately 200 patients with MSA. Participants will be randomized in a 1:1 ratio to receive ATH434 50 mg twice daily or matching placebo over 12 months.

The FDA aligned with Alterity on using the 11-item Unified Multiple System Atrophy Rating Scale (UMSARS) Part I as the primary endpoint, measuring activities of daily living affected by MSA.

Key secondary endpoints will include the Swallowing Disturbance Questionnaire (SDQ), Orthostatic Hypotension Symptom Assessment (OHSA), and Clinical Global Impression of Severity (CGI-S).

The agency also indicated that data from the previously completed ATH434-201 Phase 2 trial could serve as the confirmatory evidence supporting a future approval. An open-label extension is planned for participants completing Phase 3 to provide continued treatment and expand long-term safety data.

Regulatory alignment strengthens development program

Chief Executive Officer David Stamler, MD, said the official FDA minutes confirm the regulatory alignment achieved during the End-of-Phase 2 meeting and provide a clearly defined registration strategy. He noted that agreement on a single pivotal trial supported by confirmatory evidence offers an efficient pathway toward potential NDA submission while allowing the company to proceed with final protocol preparations.

Chief Medical Advisor Daniel Claassen, MD, said the encouraging Phase 2 findings and FDA agreement on the Phase 3 design represent an important step toward developing a disease-modifying treatment option for people living with MSA.

Path Forward

With FDA agreement on the pivotal study design now formally documented, Alterity plans to finalize the Phase 3 protocol and initiate trial activities before the end of 2026. If successful, the program could support an NDA based on one pivotal study complemented by existing Phase 2 evidence, potentially accelerating development of one of the few investigational therapies targeting disease progression in multiple system atrophy.

Reference

 ASX:ATH – FDA Meeting Minutes Confirm Registrational Path for ATH434