Annexon Announces Closing of Public Offering and Full Exercise of Underwriters’ Option to Purchase Additional Shares for Gross Proceeds of $86.25 Million

Rhea-AI Summary

Annexon (Nasdaq: ANNX) closed an underwritten public offering on Nov 14, 2025, issuing 29,423,075 shares of common stock including the full exercise of a 4,326,922-share underwriters’ option and issuing 3,750,000 pre-funded warrants.

The public offering price was $2.60 per share (pre-funded warrant price $2.599) and gross proceeds were approximately $86.25 million before fees. Goldman Sachs, TD Cowen and Wells Fargo served as joint book-running managers.

Positive

• Gross proceeds of $86.25 million
• Underwriters’ option fully exercised (4,326,922 shares)
• Pre-funded warrants enabled participation by certain investors

Negative

• Share issuance of 29,423,075 may dilute existing shareholders
• Pre-funded warrants for 3,750,000 shares create additional potential dilution

Insights

Capital Markets Analyst

Annexon closed an underwritten offering raising approximately $86.25 million, strengthening near-term liquidity.

The transaction sold 29,423,075 common shares (including a full underwriters' option) and pre-funded warrants, at a public price of $2.60 per share (and $2.599 per pre-funded warrant), generating gross proceeds of about $86.25 million. This funding event executed through a shelf registration provides immediate cash to support operations tied to its late-stage clinical platform.

Key dependencies and risks include the net proceeds after underwriting discounts and offering expenses, which will determine actual runway, and how management allocates the cash across clinical programs and overhead. Dilution to existing shareholders is explicit given the new shares and warrants; the market will price that dilution against the value of progressing clinical assets.

Watch for disclosures of net proceeds and a use-of-proceeds schedule in subsequent filings and for any updates on clinical milestones over the next 6–12 months that could materially change the companys cash needs and valuation.

BRISBANE, Calif., Nov. 14, 2025 (GLOBE NEWSWIRE) -- Annexon, Inc. (“Annexon”) (Nasdaq: ANNX), a biopharmaceutical company advancing a late-stage clinical platform targeting neuroinflammation across life-changing complement-mediated diseases of the body, brain, and eye, today announced the closing of its previously announced underwritten public offering of 29,423,075 shares of its common stock, which includes the full exercise of the underwriters’ option to purchase 4,326,922 additional shares of common stock, at a price to the public of $2.60 per share and, in lieu of shares of common stock to certain investors, pre-funded warrants to purchase 3,750,000 shares of common stock at a purchase price of $2.599 per share, which equals the public offering price per share of the common stock less the $0.001 exercise price per share of each pre-funded warrant. The gross proceeds to Annexon from the offering were approximately $86.25 million, before deducting underwriting discounts and commissions and other offering expenses payable by Annexon.

Goldman Sachs & Co. LLC, TD Cowen and Wells Fargo Securities acted as joint book-running managers for the offering.

The offering was made by Annexon pursuant to a shelf registration statement on Form S-3, including a base prospectus, that was filed with the Securities and Exchange Commission (the “SEC”) on March 26, 2024 and subsequently declared effective by the SEC on April 1, 2024. Copies of the final prospectus supplement and the accompanying prospectus relating to the offering can be accessed for free through the SEC’s website at www.sec.gov. Copies of the final prospectus supplement and the accompanying prospectus, when available, may also be obtained from: Goldman Sachs & Co. LLC, Attention: Prospectus Department, 200 West Street, New York, NY 10282, by telephone at (866) 471-2526 or by email at prospectus-ny@ny.email.gs.com; TD Securities (USA) LLC, 1 Vanderbilt Avenue, New York, NY 10017, c/o Broadridge Financial Solutions, 1155 Long Island Avenue, Edgewood, NY 11717 or by email at TDManualrequest@broadridge.com; or Wells Fargo Securities, 90 South 7th Street, 5th Floor, Minneapolis, MN 55402, by telephone at 800-645-3751 (option #5), or by email at WFScustomerservice@wellsfargo.com.

This press release shall not constitute an offer to sell or the solicitation of an offer to buy nor shall there be any sale of these securities in any state or jurisdiction in which such an offer, solicitation or sale would be unlawful prior to registration or qualification under the securities laws of any such state or jurisdiction.

About Annexon

Annexon, Inc. (Nasdaq: ANNX) is developing the next generation of complement inhibitors to stop neuroinflammation as first-in-kind treatments for millions of people living with serious neuroinflammatory diseases of the body, brain and eye. Our novel scientific approach focuses on C1q, the initiating molecule of classical complement’s potent inflammatory pathway that when misdirected can lead to tissue damage and loss in a host of diseases. By targeting C1q, our immunotherapies are designed to stop this neuroinflammatory cascade before it starts. Our pipeline spans three diverse therapeutic areas – autoimmunity, neurodegeneration and ophthalmology – and includes targeted investigational drug candidates designed to address the unmet needs of nearly 10 million people worldwide. Annexon’s mission is to deliver game-changing therapies to patients so that they can live their best lives.

Investor Contact:

Joyce Allaire
LifeSci Advisors
jallaire@lifesciadvisors.com

Media Contact:

Beth Keshishian
917-912-7195
beth@bethkeshishian.com

FAQ

How many shares did Annexon sell in the Nov 14, 2025 offering (ANNX)?

Annexon sold 29,423,075 shares of common stock, including the full exercise of the underwriters’ option.

What were the offering price and gross proceeds for Annexon (ANNX) on Nov 14, 2025?

The public offering price was $2.60 per share and gross proceeds were approximately $86.25 million before fees.

What are the pre-funded warrants in the Annexon (ANNX) offering and how many were issued?

Pre-funded warrants to purchase 3,750,000 shares were issued at a purchase price of $2.599 per share.

Which banks managed Annexon’s (ANNX) Nov 14, 2025 offering?

Goldman Sachs, TD Cowen and Wells Fargo acted as joint book-running managers.

Will the Annexon (ANNX) offering cause shareholder dilution?

Yes; the issuance of 29.4 million shares plus 3.75 million pre-funded warrants represents potential dilution to existing holders.

Under what registration statement was the Annexon (ANNX) offering made?

The offering was made under a Form S-3 shelf registration declared effective by the SEC on April 1, 2024.