SEC Form S-8 filed by Eton Pharmaceuticals Inc.

Registration No. 333-

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM S-8

REGISTRATION STATEMENT

Under

THE SECURITIES ACT OF 1933

Eton Pharmaceuticals, Inc.

(Exact name of registrant as specified in its charter)

21925 W. Field Parkway, Suite 235

Deer Park, Illinois 60010

(Address of Principal Executive Offices) (Zip Code)

2018 Equity Incentive Plan

2018 Employee Stock Purchase Plan

(Full titles of the plans)

Sean E. Brynjelsen

President and Chief Executive Officer

Eton Pharmaceuticals, Inc.

21925 W. Field Parkway, Suite 235

Deer Park, Illinois 60010

(847) 787-7361

(Name, address, and telephone number, including area code, of agent for service)

Copies to:

Indicate by check mark whether the Registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, a smaller reporting company or an emerging growth company. See the definitions of “large accelerated filer,” “accelerated filer,” “smaller reporting company,” and “emerging growth company” in Rule 12b-2 of the Exchange Act.

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 7(a)(2)(B) of the Securities Act. ☐

EXPLANATORY NOTE

Eton Pharmaceuticals, Inc. (the “Registrant”) has prepared this registration statement (this “Registration Statement”) in accordance with the requirements of Form S-8 under the Securities Act to register 1,068,363 additional shares of Common Stock reserved for issuance under the Eton Pharmaceuticals, Inc. 2018 Equity Incentive Plan (the “2018 Plan”) and 150,000 additional shares of Common Stock reserved for issuance under the Eton Pharmaceuticals, Inc. 2018 Employee Stock Purchase Plan (the “2018 ESPP”).

Pursuant to the Registration Statements on Form S-8 (File Nos. 333-228493, 333-230572, 333-270707 and 333-278234) filed by the Registrant with the Securities and Exchange Commission (the “Commission”) on November 20, 2018, March 28, 2019, March 21, 2023 and March 25, 2024 (the “Prior Registration Statements”), the Registrant previously registered an aggregate of 7,699,634 shares of Common Stock under the 2018 Plan and an aggregate of 1,050,000 shares of Common Stock under the 2018 ESPP.

In accordance with General Instruction E to Form S-8, the contents of the Prior Registration Statements are hereby incorporated by reference.

PART I

INFORMATION REQUIRED IN THE SECTION 10(A) PROSPECTUS

The information specified in Item 1 and Item 2 of Form S-8 is omitted from this Registration Statement in accordance with the provisions of Rule 428 under the Securities Act of 1933, as amended (the “Securities Act”) and the introductory note to Part I of Form S-8. The documents containing the information specified in Part I of Form S-8 will be delivered to the participants in the equity benefit plans covered by this Registration Statement as specified by Rule 428(b)(1) under the Securities Act.

PART II

INFORMATION REQUIRED IN THE REGISTRATION STATEMENT

ITEM 3. INCORPORATION OF DOCUMENTS BY REFERENCE.

The following documents filed by the Registrant with the Commission are hereby incorporated by reference into this Registration Statement:

All other reports and other documents subsequently filed by the Registrant pursuant to Sections 13(a), 13(c), 14 or 15(d) of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), prior to the filing of a post-effective amendment which indicates that all securities offered hereby have been sold or which deregisters all securities then remaining unsold, shall be deemed to be incorporated by reference into this Registration Statement and to be part of this Registration Statement from the date of the filing of such reports and documents, except as to any portion of any future annual or quarterly report to stockholders or document or current report furnished under Items 2.02 or 7.01 of Form 8-K that is not deemed filed under such provisions.

For purposes of this Registration Statement, any statement contained in a document incorporated or deemed to be incorporated by reference herein shall be deemed to be modified or superseded to the extent that a statement contained herein or in any other subsequently filed document that also is or is deemed to be incorporated by reference herein modifies or supersedes such statement. Any such statement so modified or superseded shall not be deemed, except as so modified or superseded, to constitute a part of this Registration Statement.

You should rely only on the information provided or incorporated by reference in this Registration Statement or any related prospectus. The Registrant has not authorized anyone to provide you with different information. You should not assume that the information in this Registration Statement or any related prospectus is accurate as of any date other than the date on the front of the document.

You may contact the Registrant in writing or orally to request copies of the above-referenced filings, without charge (excluding exhibits to such documents unless such exhibits are specifically incorporated by reference into the information incorporated into this Registration Statement). Requests for such information should be directed to:

Eton Pharmaceuticals, Inc.

21925 W. Field Parkway, Suite 235

Deer Park, Illinois 60010

(847) 787-7361

Attn: Chief Executive Officer

Item 8. EXHIBITS.

*Filed herewith

SIGNATURES

Pursuant to the requirements of the Securities Act of 1933, as amended, the Registrant certifies that it has reasonable grounds to believe that it meets all of the requirements for filing on Form S-8 and has duly caused this Registration Statement to be signed on its behalf by the undersigned, thereunto duly authorized, in the City of Deer Park, State of Illinois, on November 19, 2025.

Eton Pharmaceuticals, Inc.

POWER OF ATTORNEY

KNOW ALL PERSONS BY THESE PRESENTS, that each person whose signature appears below constitutes and appoints Sean E. Brynjelsen and James R. Gruber, and each or any one of them, as his or her true and lawful attorneys-in-fact and agents, with full power of substitution and resubstitution, for him or her and in his or her name, place or stead, in any and all capacities, to sign any and all amendments (including post-effective amendments) to this Registration Statement, and to file the same, with all exhibits thereto and other documents in connection therewith, with the Securities and Exchange Commission, granting unto said attorneys-in-fact and agents, and each of them, full power and authority to do and perform each and every act and thing requisite and necessary to be done in connection therewith, as fully to all intents and purposes as he or she might or could do in person, hereby ratifying and confirming all that said attorneys-in-fact and agents, or any of them, or their or his substitute or substitutes, may lawfully do or cause to be done by virtue hereof.

Pursuant to the requirements of the Securities Act of 1933, as amended, this Registration Statement has been signed by the following persons in the capacities and on the dates indicated.