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): June 23, 2025

ANNEXON, INC.

(Exact name of registrant as specified in its charter)

Delaware

001-39402

27-5414423

(State or other jurisdiction

of incorporation)

(Commission

File Number)

(IRS Employer

Identification No.)

1400 Sierra Point Parkway, Bldg C, Suite 200

Brisbane, California 94005

(Address of principal executive offices) (Zip Code)

Registrant’s telephone number, including area code: (650) 822-5500

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, par value $0.001 per share

ANNX

The Nasdaq Stock 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 3.03 Material Modification to the Rights of Security Holders.

2022 Common Warrant Amendments

On June 23, 2025, Annexon, Inc. (the “Company”) and certain holders thereof entered into amendments to the common stock purchase warrants (the “Common Warrants”) originally issued pursuant to that certain Securities Purchase Agreement, dated July 7, 2022, by and among the Company and the purchasers party thereto (the “Common Warrant Amendment”). The Common Warrant Amendment extends the term of such Common Warrants by one year until June 30, 2026 and enables such holders to only effect a cash-based exercise of the Common Warrants at an exercise price per share of $5.806875. The participating investors hold Common Warrants exercisable for up to 6,877,622 shares of the Company’s common stock. The Company would receive aggregate proceeds of up to approximately $39.9 million if all of the Common Warrants are exercised (without regard to any ownership limitations).

The foregoing summary of the Common Warrant Amendment does not purport to be complete and is qualified in its entirety by reference to the form of Common Warrant Amendment attached hereto as Exhibit 4.1 and is incorporated herein by reference.

Cautionary Note Regarding Forward-Looking Statements

This Current Report on Form 8-K may contain forward-looking statements made in reliance upon the safe harbor provisions of Section 27A of the Securities Act of 1933, as amended, and Section 21E of the Securities Exchange Act of 1934, as amended. Forward-looking statements include all statements that do not relate solely to historical or current facts, and can be identified by the use of words such as “may,” “will,” “expect,” “project,” “estimate,” “anticipate,” “plan,” “believe,” “potential,” “should,” “continue” or the negative versions of those words or other comparable words. These forward-looking statements include statements about the potential proceeds to the Company upon the exercise of the Common Warrants. These forward-looking statements are based on information currently available to the Company and its current plans or expectations, and are subject to a number of uncertainties and risks that could significantly affect current plans. Actual results and performance could differ materially from those projected in the forward-looking statements as a result of many factors, including the likelihood of cash exercise during the extended term and potential proceeds to be received by the Company. The Company’s forward-looking statements also involve assumptions that, if they prove incorrect, would cause its results to differ materially from those expressed or implied by such forward-looking statements. These and other risks concerning the Company’s business are described in additional detail in the Company’s Annual Report on Form 10-K for the year ended December 31, 2024, the Company’s Quarterly Report on Form 10-Q for the quarter ended March 31, 2025 and in the Company’s other Periodic and Current Reports filed with the Securities and Exchange Commission. The Company is under no obligation to (and expressly disclaims any such obligation to) update or alter its forward-looking statements, whether as a result of new information, future events or otherwise.

Item 9.01

Financial Statements and Exhibits.

(d) Exhibits.


Exhibit No.		Description

4.1		Form of Common Warrant Amendment.

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.

Dated: June 25, 2025

Annexon, Inc.

/s/ Jennifer Lew

Jennifer Lew

Executive Vice President and Chief Financial Officer

Annexon, Inc. 8-K