[8-K] Amylyx Pharmaceuticals, Inc. Reports Material Event

Rhea-AI Filing Summary

Amylyx Pharmaceuticals filed a Current Report (Form 8-K) that includes an underwriting agreement dated September 9, 2025, and counsel materials from Goodwin Procter LLP. The filing discloses that an opinion and consent of Goodwin Procter LLP are included as exhibits, and that the cover page interactive data file is embedded within the Inline XBRL document. The report contains a standard forward-looking statements caution referencing prior SEC reports and urges investors not to rely solely on forward-looking statements. The filing is signed by James M. Frates, Chief Financial Officer, dated September 10, 2025.

Positive

• Underwriting agreement is identified and dated (September 9, 2025), indicating formal underwriting arrangements exist
• Legal opinion and consent from Goodwin Procter LLP are included as exhibits, supporting legal compliance for the transaction
• Inline XBRL cover page is embedded, showing adherence to interactive data filing requirements

Negative

• Key transaction details are absent in the provided excerpt: offering size, pricing, and use of proceeds are not stated
• The filing text is incomplete (the document label 'Current Report on' is blank), limiting ability to assess material impact
• Standard forward-looking disclaimer warns investors not to rely on projections, highlighting uncertainty

Insights

Corporate Governance Expert

TL;DR: Routine disclosure of underwriting agreement and legal opinion; limited substantive detail in this excerpt.

The filing lists an underwriting agreement dated September 9, 2025, and confirms inclusion of legal opinion and consent from Goodwin Procter LLP, which are typical exhibits supporting an offering. The presence of an embedded Inline XBRL cover page indicates compliance with interactive data requirements. However, the excerpt lacks transaction economics, offering size, use of proceeds, or other material terms that investors need to assess governance or dilution effects.

Securities/Compliance Attorney

TL;DR: Filing contains required legal exhibits and standard forward-looking statement disclaimers; not a material event by itself in this text.

The document explicitly includes an underwriting agreement and counsel opinion/consent as exhibits, which are standard for registered offerings. The forward-looking statement language cites prior SEC filings as sources of risk disclosures. The excerpt does not provide specifics of the offering or any ongoing liabilities, so its immediate material impact cannot be determined from the provided content alone.

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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): September 9, 2025

AMYLYX PHARMACEUTICALS, INC.

(Exact name of registrant as specified in its charter)

Delaware		001-41199		46-4600503
(State or other jurisdiction of incorporation)		(Commission File Number)		(IRS Employer 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 Symbol(s)		Name of each exchange 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. ☐

Item 1.01. Entry into a Material Definitive Agreement.

On September 9, 2025, Amylyx Pharmaceuticals, Inc. (“Amylyx” or the “Company”) entered into an underwriting agreement (the “Underwriting Agreement”) with Leerink Partners LLC and Guggenheim Securities, LLC, as representatives of the several underwriters named therein (the “Underwriters”), relating to the issuance and sale of an aggregate of 17,500,000 shares (the “Firm Shares”) of the Company’s common stock, par value $0.0001 per share (“Common Stock”), at a price to the public of $10.00 per share (the “Offering”). Pursuant to the Underwriting Agreement, the Company also granted the Underwriters a 30-day option to purchase up to 2,625,000 additional shares of Common Stock at the public offering price less the underwriting discounts and commissions (the “Option Shares” and together with the Firm Shares, the “Shares”).

The aggregate net proceeds to the Company, after deducting underwriting discounts and commissions and other estimated offering expenses payable by the Company, will be approximately $164.0 million, or approximately $188.7 million if the option to purchase the Option Shares is exercised in full by the Underwriters. Amylyx intends to use the net proceeds from this Offering, together with existing cash, cash equivalents and marketable securities, to advance avexitide commercial readiness and for research and development, working capital and other general corporate purposes. The Offering is expected to close on September 11, 2025, subject to customary closing conditions. All of the Shares in the Offering are being sold by the Company.

The Underwriting Agreement contains customary representations and warranties, conditions to closing, market standoff provisions, termination provisions and indemnification obligations, including for liabilities under the Securities Act of 1933, as amended. The representations, warranties and covenants contained in the Underwriting Agreement were made only for purposes of such agreement and as of specific dates, and were solely for the benefit of the parties to the Underwriting Agreement.

The Offering is being made pursuant to a prospectus supplement, dated September 9, 2025 (the “Prospectus Supplement”), filed with the Securities and Exchange Commission (“SEC”) on September 10, 2025, and an accompanying base prospectus that forms a part of the registration statement on Form S-3 (File No. 333- 285525), filed with the SEC on March 4, 2025 and declared effective by the SEC on March 26, 2025. This Current Report on Form 8-K does not constitute an offer to sell or a solicitation of an offer to buy shares of Common Stock.

The foregoing description of certain terms of the Underwriting Agreement and the transactions contemplated thereby does not purport to be complete, and is subject to and qualified in its entirety by reference to the full text of the Underwriting Agreement that is filed as Exhibit 1.1 to this Current Report on Form 8-K and is incorporated by reference herein.

The legal opinion of Goodwin Procter LLP relating to the legality of the issuance and sale of the Shares in the Offering is filed as Exhibit 5.1 to this Current Report on Form 8-K.

Forward Looking Statements

Statements contained in this Current Report on Form 8-K regarding matters that are not historical facts are “forward-looking statements” within the meaning of the Private Securities Litigation Reform Act of 1995, as amended, including with respect to the completion of the Offering, the potential exercise by the underwriters of the option to purchase additional shares, the anticipated closing date of the Offering, the expected amount of proceeds from the Offering and the expected use of proceeds from the Offering. No assurance can be given that the Offering discussed above will be completed. Because such statements are subject to risks and uncertainties, actual results may differ materially from those expressed or implied by such forward-looking statements. Any forward-looking statements in this Current Report on Form 8-K are based on management’s current expectations of future events and are subject to a number of risks and uncertainties that could cause actual results to differ materially and adversely from those set forth in or implied by such forward-looking statements. Risks that contribute to the uncertain nature of the forward-looking statements include those risks and uncertainties set forth in Amylyx’ SEC filings, including Amylyx’ Annual Report on Form 10-K for the year ended December 31, 2024, Quarterly Report on Form 10-Q for the quarterly period ended June 30, 2025, and subsequent filings with the SEC. All forward-looking statements contained in this Current Report on Form 8-K speak only as of the date on which they were made. Amylyx undertakes no obligation to update such statements to reflect events that occur or circumstances that exist after the date on which they were made. In light of the foregoing, investors are urged not to rely on any forward-looking statement in reaching any conclusion or making any investment decision about any securities of Amylyx.

Item 9.01. Financial Statements and Exhibits.

(d) Exhibits

Exhibit No.		Description
1.1		Underwriting Agreement, dated September 9, 2025
5.1		Opinion of Goodwin Procter LLP
23.1		Consent of Goodwin Procter LLP (included in Exhibit 5.1)
104		Cover Page Interactive Data File (embedded within the Inline XBRL document)

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.
Date: September 10, 2025				By:		/s/ James M. Frates
						James M. Frates
						Chief Financial Officer

FAQ

Does the Amylyx (AMLX) 8-K include an underwriting agreement?

Yes. The excerpt references an Underwriting Agreement dated September 9, 2025.

Who provided the legal opinion and consent in the AMLX filing?

Goodwin Procter LLP is identified as providing the opinion and consent included as exhibits.

When was the 8-K signed and by whom?

The filing excerpt is signed by James M. Frates, Chief Financial Officer, dated September 10, 2025.

Does the 8-K include forward-looking statements or disclaimers?

Yes. The filing contains standard forward-looking statement language referencing risks in Amylyx's prior SEC reports and stating no obligation to update such statements.

Is interactive XBRL data included in the filing?

Yes. The excerpt states the Cover Page Interactive Data File is embedded within the Inline XBRL document.