# EDGAR Filing Document

**Accession Number:** 0001658551
**File Stem:** 0001193125-25-189109
**Filing Date:** 2025-8
**Character Count:** 4458
**Document Hash:** 7f1cea9c0bf8062810f56860856e709d
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0001193125-25-189109.hdr.sgml**: 20250827

**ACCESSION NUMBER**: 0001193125-25-189109

**CONFORMED SUBMISSION TYPE**: 8-K

**PUBLIC DOCUMENT COUNT**: 12

**CONFORMED PERIOD OF REPORT**: 20250827

**ITEM INFORMATION**: Other Events

**FILED AS OF DATE**: 20250827

**DATE AS OF CHANGE**: 20250827

**FILER**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** Amylyx Pharmaceuticals, Inc.
- **CENTRAL INDEX KEY:** 0001658551
- **STANDARD INDUSTRIAL CLASSIFICATION:** PHARMACEUTICAL PREPARATIONS [2834]
- **ORGANIZATION NAME:** 03 Life Sciences
- **EIN:** 464600503
- **STATE OF INCORPORATION:** DE
- **FISCAL YEAR END:** 1231

**FILING VALUES:**
- **FORM TYPE:** 8-K
- **SEC ACT:** 1934 Act
- **SEC FILE NUMBER:** 001-41199
- **FILM NUMBER:** 251259689

**BUSINESS ADDRESS:**
- **STREET 1:** 43 THORNDIKE STREET
- **CITY:** CAMBRIDGE
- **STATE:** MA
- **ZIP:** 02141
- **BUSINESS PHONE:** 617-683-0917

**MAIL ADDRESS:**
- **STREET 1:** 43 THORNDIKE STREET
- **CITY:** CAMBRIDGE
- **STATE:** MA
- **ZIP:** 02141

?xml version='1.0' encoding='ASCII'? 8-K

### UNITED STATES

### SECURITIES AND EXCHANGE COMMISSION

#### WASHINGTON, D.C. 20549

### FORM 8-K

#### CURRENT REPORT

#### Pursuant to Section 13 or 15(d)

#### of the Securities Exchange Act of 1934

#### Date of Report (Date of earliest event reported): August 27, 2025

## AMYLYX PHARMACEUTICALS, INC.

#### (Exact name of Registrant as Specified in Its Charter)

---

| | | |
|:---|:---|:---|
| **Delaware** | **001-41199** | **46-4600503** |
| **(State or Other Jurisdiction**<br> **of Incorporation)** | **(Commission**<br> **File Number)** | **(IRS Employer**<br> **Identification No.)** |

---

---

| | |
|:---|:---|
| **43 Thorndike St.,** |  |
| **Cambridge, MA** | **02141** |
| **(Address of Principal Executive Offices)** | **(Zip Code)** |

---

#### Registrant's Telephone Number, Including Area Code: (617) 682-0917

#### Not Applicable

#### (Former Name or Former Address, if Changed Since Last Report)
Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

☐ Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)

☐ Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)

☐ Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))

☐ Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Securities registered pursuant to Section 12(b) of the Act:

---

| | | |
|:---|:---|:---|
| **Title of each class** | **Trading**<br> **Symbol(s)** | **Name of each exchange<br>on which registered** |
| Common Stock, $0.0001 par value per share | AMLX | Nasdaq Global Select Market |

---

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§ 230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§ 240.12b-2 of this chapter).

Emerging growth company ☐

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐

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#### Item 8.01 Other Events
On August 27, 2025, Amylyx Pharmaceuticals, Inc. (the "Company") announced it is discontinuing the ORION program of AMX0035 (sodium phenylbutyrate [PB] and taurursodiol [TURSO, also known as ursodoxicoltaurine]) in adults living with progressive supranuclear palsy.

AMX0035 did not show differences compared to placebo on primary or secondary outcomes at Week 24. Based on these results, the Company will discontinue the Phase 2b trial and open-label extension and will not initiate the Phase 3 portion of the program. Safety data were consistent with safety data from prior studies of AMX0035.

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#### SIGNATURES
Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

---

| | | |
|:---|:---|:---|
|  | **AMYLYX PHARMACEUTICALS, INC.** | **AMYLYX PHARMACEUTICALS, INC.** |
| Date: August 27, 2025 | By: | /s/ James M. Frates |
|  |  | James M. Frates |
|  |  | Chief Financial Officer |

---