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FEDERAL REGISTER · NOTICEAugust 29, 2025

Amylyx Pharmaceuticals, Inc.; Withdrawal of Approval of New Drug Application for RELYVRIO (Sodium Phenylbutyrate and Taurursodiol) for Suspension, 3 Gram/Packet and 1 Gram/Packet

Document type
Notice
Agency
Health and Human Services Department
Published
August 29, 2025
Document number
2025-16646
ABSTRACT

The Food and Drug Administration (FDA or Agency) is withdrawing approval of the new drug application (NDA) for RELYVRIO (sodium phenylbutyrate and taurursodiol) for suspension, 3 gram (g)/ packet and 1 g/packet, held by Amylyx Pharmaceuticals, Inc. (Amylyx), 43 Thorndike St., Cambridge, MA 02141. Amylyx has voluntarily requested that FDA withdraw approval of this application and has waived its opportunity for a hearing.

Abstract as published in the Federal Register.

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Document details are published in the U.S. Federal Register; SPEQ surfaces them for reference and is not affiliated with or endorsed by the FDA or the Office of the Federal Register. The authoritative text is on federalregister.gov.