SEC Form S-8 filed by Dianthus Therapeutics Inc.

EXPLANATORY NOTE

This Registration Statement on Form S-8 (this “Registration Statement”) registers (i) 2,161,025 additional shares of common stock, $0.001 par value per share (“Common Stock”), of Dianthus Therapeutics, Inc. (the “Registrant”) under the Second Amended and Restated Dianthus Therapeutics, Inc. Stock Option and Incentive Plan (the “Incentive Plan”), (ii) 62,500 additional shares of Common Stock under the Dianthus Therapeutics, Inc. 2019 Employee Stock Purchase Plan, as amended (the “ESPP”), and (iii) 600,000 additional shares under the Dianthus Therapeutics, Inc. Equity Inducement Plan (the "Inducement Plan"), which was approved by the Registrant’s board of directors on December 17, 2025 to provide for the grant of additional inducement awards under the Inducement Plan in accordance with the requirement of Nasdaq Listing Rule 5635(c)(4).

The number of shares of Common Stock reserved and available for issuance under the Incentive Plan is subject to an automatic annual increase on each January 1 by an amount equal to the lesser of 5% of the number of shares of Common Stock issued and outstanding on the immediately preceding December 31 or such lesser number of shares of Common Stock as determined by the Administrator (as defined in the Incentive Plan). Accordingly, on January 1, 2026, the number of shares of Common Stock reserved and available for issuance under the Incentive Plan increased by 2,161,025 shares. The additional shares are of the same class as other securities relating to the Incentive Plan for which the Registrant’s registration statement filed Form S-8 filed with the Securities and Exchange Commission (the “SEC”) on March 11, 2025, August 8, 2024, March 21, 2024, October 4, 2023, March 8, 2022, March 3, 2021, March 3, 2020, March 19, 2019 and June 22, 2018 (Registration Nos. 333-285709, 333-281381, 333-278151, 333-274865, 333-263358, 333-253815, 333-236853, 333-230387, and 333-225838), and which, together with all exhibits filed therewith or incorporated therein by reference, are hereby incorporated by reference pursuant to General Instruction E to Form S-8 and the shares of Common Stock registered hereunder with respect to the Incentive Plan are in addition to the shares of Common Stock registered on such registration statements.

The number of shares of Common Stock reserved and available for issuance under the ESPP is subject to an automatic annual increase on each January 1 by an amount equal to the least of (i) 1% of the number of shares of Common Stock issued and outstanding on the immediately preceding December 31, (ii) 62,500 shares of Common Stock or (iii) such number of shares of Common Stock as determined by the Administrator (as defined in the ESPP). Accordingly, on January 1, 2026, the number of shares of Common Stock reserved and available for issuance under the ESPP increased by 62,500. The additional shares are of the same class as other securities relating to the ESPP for which the Registrant’s registration statement filed on Form S-8 filed with the SEC on March 11, 2025, March 21, 2024, March 8, 2022 and August 8, 2019 (Registration Nos. 333-285709, 333-278151, 333-263358 and 333-233125), and which, together with all exhibits filed therewith or incorporated therein by reference, are hereby incorporated by reference pursuant to General Instruction E to Form S-8 and the shares of Common Stock registered hereunder with respect to the ESPP are in addition to the shares of Common Stock registered on such registration statements.

The number of shares of Common Stock reserved and available for issuance under the Inducement Plan was increased by an additional 600,000 shares pursuant to approval by the Registrant's Board of Directors on December 17, 2025. The additional shares are of the same class as other securities relating to the Inducement Plan for which the Registrant’s registration statement filed on Form S-8 filed with the SEC on March 21, 2024 (Registration No. 333-278151), and which, together with all exhibits filed therewith or incorporated therein by reference, are hereby incorporated by reference pursuant to General Instruction E to Form S-8 and the shares of Common Stock registered hereunder with respect to the Inducement Plan are in addition to the shares of Common Stock registered on such registration statements.

PART I

INFORMATION REQUIRED IN THE SECTION 10(a) PROSPECTUS

Item 1. Plan Information

The documents containing the information specified in Part I of this Registration Statement will be delivered to employees as specified by Rule 428(b)(1) of the Securities Act of 1933, as amended (the “Securities Act”). In accordance with the instructions to Part I of Form S-8, such documents are not being filed with the SEC either as part of this Registration Statement or as prospectuses or prospectus supplements pursuant to Rule 424 of the Securities Act. Such documents and the documents incorporated by reference in this Registration Statement pursuant to Item 3 of Part II of Form S-8, taken together, constitute a prospectus that meets the requirements of Section 10(a) of the Securities Act.

PART II

INFORMATION REQUIRED IN THE REGISTRATION STATEMENT

Item 8. Exhibits.

* Filed herewith.

SIGNATURES

Pursuant to the requirements of the Securities Act, 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 New York, State of New York, on March 9, 2026.

POWER OF ATTORNEY

KNOW ALL PERSONS BY THESE PRESENTS, that each person whose signature appears below hereby constitutes and appoints each of Marino Garcia, Ryan Savitz and Adam Veness and each of them acting individually, as his or her true and lawful attorneys-in-fact and agents, each with full power of substitution and resubstitution in each of them singly, for him or her and in his or her name, place and stead, and 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 SEC, granting to the attorneys-in-fact and agents, and each of them, full power and authority to do and perform each and every act and thing requisite or necessary to be done in or about the premises, as full to all intents and purposes as he or she might or could do in person, hereby ratifying and confirming all that the attorneys-in-fact and agents or any of each of them or their substitutes may lawfully do or cause to be done by virtue hereof.

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