Amylyx Pharmaceuticals, Inc. announced topline results from PHOENIX, a global, 48-week, randomized, placebo-controlled Phase 3 clinical trial of AMX0035 (sodium phenylbutyrate and taurursodiol [also known as ursodoxicoltaurine; RELYVRIO®? in the U.S., ALBRIOZAtm in Canada) in people living with amyotrophic lateral sclerosis (ALS). PHOENIX did not meet its primary endpoint of reaching statistical significance (p=0.667) as measured by change from baseline in the Revised Amyotrophic Lateral Sclerosis Functional Rating Scale (ALSFRS-R) total score at Week 48, nor was there statistical significance seen in secondary endpoints.

Amylyx plans to present the data from PHOENIX at an upcoming medical meeting and will publish the results in a medical journal later this year. Amylyx will continue to engage with regulatory authorities and the broader ALS community, including ALS specialists and other multidisciplinary experts, people living with ALS, and advocates, to discuss the results from PHOENIX within the next eight weeks and make informed decisions. Amylyx intends to share plans for RELYVRIO/ALBRIOZA in ALS, which may include voluntarily withdrawing RELYVRIO/alBRIOZA from the market.

At this time, RELYVRIO/ALBRIOZA and its related patient support program will continue to be available for people living with ALS. Amylyx has voluntarily decided to pause promotion of the medication during this time. PHOENIX Study Results: The Phase 3 PHOENIX study enrolled 664 adults living with ALS.

Additionally, AMX0035 has been shown to also reduce markers associated with neurodegenerative diseases in clinical trials, including a reduction of tau, a key protein aggregate shared across several neurodegenerative diseases, and YKL-40, a marker of neuroinflammation. Update on Ongoing AMX0035 Studies: The global, randomized, double-blind, placebo-controlled Phase 3 ORION clinical study of AMX0035 in PSP remains ongoing. Data from the ongoing 12-participant, single site, open-label Phase 2 HELIOS clinical study are demonstrating evidence of clinical activity of AMX0035 in Wolfram syndrome.

This study is fully recruited, and the Company plans to present preliminary data in the second quarter of 2024.