As filed with the Securities and Exchange Commission on March 23, 2026

Registration Statement No. 333-

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM S-8

REGISTRATION STATEMENT UNDER THE SECURITIES ACT OF 1933

Avalo Therapeutics, Inc.

(Exact name of registrant as specified in its charter)

Avalo Therapeutics, Inc. Fourth Amended and Restated 2016 Equity Incentive Plan 

Avalo Therapeutics, Inc. Amended and Restated 2016 Employee Stock Purchase Plan

(Full title of the plans)

Christopher Sullivan, Chief Financial Officer

Avalo Therapeutics, Inc.

1500 Liberty Ridge Drive, Suite 321

Wayne, Pennsylvania 19087

(410) 522-8707

(Name, address, including zip code, 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

This Registration Statement is being filed to register:

all of which are securities of the same class for which Registration Statements on Form S-8 are effective. Accordingly, the contents of the previous Registration Statements on Form S-8 filed by the Registrant with the Securities and Exchange Commission (the “Commission”) on May 20, 2016 (File No. 333-211490), May 20, 2016 (File No. 333-211491), August 10, 2018 (File No. 333-226767), August 6, 2020 (File No. 333-241661), May 13, 2021 (File No. 333-256082), May 13, 2021 (File No. 333-256083), November 7, 2022 (File No. 333-268199), May 4, 2023 (File No. 333-271655), November 7, 2024 (File No. 333-283047), May 12, 2025 (File No. 333-287175), May 12, 2025 (File No. 333-287176), and November 6, 2025 (File No. 333-291304) including periodic and current reports filed after the previous Registration Statements on Form S-8 to maintain current information about the Registrant, are incorporated by reference into this Registration Statement pursuant to General Instruction E of Form S-8.

The additional shares are the result of the annual automatic increase provision of the 2016 Stock Plan and the ESPP.

PART II

INFORMATION REQUIRED IN THE REGISTRATION STATEMENT

The following exhibits are filed as part of this Registration Statement:

* Filed herewith.

SIGNATURES

Pursuant to the requirements of the Securities Act of 1933, 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 Wayne, State of Pennsylvania, on the 23^rd day of March, 2026.

POWER OF ATTORNEY

Each person whose signature appears below constitutes and appoints Garry A. Neil and Christopher Sullivan, and each of them, his or her true and lawful attorney-in-fact and agent, with full power of substitution and resubstitution, for him or her and in his or her name, place and 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 attorney-in-fact and agent full power and authority to do and perform each and every act and thing requisite and necessary to be done in and about the premises, as fully to all intents and purposes as he or she might or could do in person, hereby ratifying and confirming all that said attorney-in-fact and agent, 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, this Registration Statement has been signed by the following persons in the capacities and on the dates indicated.