Dianthus Therapeutics, Inc. /DE/

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, DC 20549

FORM 10-Q

(Mark One)

For the quarterly period ended September 30,2026

OR

For the transition period from _________________ to _________________

Commission File Number:001-38541

Dianthus Therapeutics, Inc.

(Exact Name of Registrant as Specified in its Charter)

Registrant’s telephone number, including area code: (929)999-4055

Securities registered pursuant to Section 12(b) of the Act:

Indicate by check mark whether the registrant (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the registrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90 days. Yes ☒ No☐

Indicate by check mark whether the registrant has submitted electronically every Interactive Data File required to be submitted pursuant to Rule 405 of Regulation S-T (§232.405 of this chapter) during the preceding 12 months (or for such shorter period that the registrant was required to submit such files). Yes ☒ No☐

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, 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 13(a) of the Exchange Act.☐

Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Exchange Act). Yes☐ No☒

As of November 2, 2026, the registrant had 56,312,712 shares of common stock, $0.001 par value per share, outstanding.

Table of Contents

i

SPECIAL NOTE REGARDING FORWARD-LOOKING STATEMENTS

This Quarterly Report on Form 10-Q contains “forward-looking statements” within the meaning of the federal securities laws, which statements are subject to substantial risks and uncertainties and are based on estimates and assumptions. All statements, other than statements of historical facts, included in this Quarterly Report on Form 10-Q are forward-looking statements, including, without limitation, statements concerning our plans, objectives, goals, expectations, hopes, beliefs, intentions, assumptions, projections, estimates or strategies and any underlying assumptions regarding the future, our future results of operations and financial position, including the sufficiency of our existing cash resources to fund our operations for as long as anticipated, our liquidity, capital resources, costs and expenses, capital requirements, commitments and contingencies, the development or commercial potential of claseprubart, DNTH212, DNTH312 or any other product candidate, our anticipated preclinical and clinical drug development activities, in particular with respect to claseprubart, DNTH212 and DNTH312, and any timelines, developments or results in connection therewith, including the timing of data, the efficacy, safety profile, dosing amount or frequency, method of delivery or other potential therapeutic benefits of claseprubart, DNTH212 and DNTH312, the receipt or timing of potential regulatory designations, approvals and commercialization of any product candidates, market size or addressable patient population and other statements, including those included under the sections titled “Risk Factors,” “Management’s Discussion and Analysis of Financial Condition and Results of Operations” and elsewhere in this Quarterly Report on Form 10-Q. In some cases, you can identify forward-looking statements by terms such as “aim,” “may,” “might,” “will,” “would,” “shall,” “objective,” “intend,” “target,” “should,” “could,” “can,” “expect,” “anticipate,” “believe,” “design,” “estimate,” “forecast,” “predict,” “project,” “potential,” “possible,” “plan,” “seek,” “contemplate,” “goal,” “likely” or “continue” or the negative of these terms and similar expressions intended to identify forward-looking statements, but the absence of these terms does not mean that a statement is not forward-looking. Forward-looking statements are not historical facts and are based on our current expectations and beliefs with respect to future events and their potential effects and impacts. There can be no assurance that future events affecting us will be those that have been anticipated. Given the significant risks and uncertainties, you should not place undue reliance on these forward-looking statements.

There are a number of risks, uncertainties and other factors that could cause our actual results or outcomes, or the timing of our results or outcomes, to differ materially from the forward-looking statements expressed or implied in this Quarterly Report on Form 10-Q. Such risks, uncertainties and other factors include, among others, the following:

•

expectations regarding the strategies, prospects, plans, expectations and objectives of our management for future operations of the Company;

•

risks associated with our ability to manage expenses and unanticipated spending and costs that could reduce our cash resources;

•

risks related to our ability to correctly estimate our operating expenses and other events;

•

changes in our capital resource requirements;

•

our ability to obtain, maintain and protect our intellectual property rights, in particular those related to our product candidates;

•

our ability to advance the development of claseprubart, DNTH212, DNTH312 and our other potential product candidates or preclinical activities under the timelines we anticipate in planned and future clinical trials;

•

our ability to replicate in later clinical trials positive results found in preclinical studies and early-stage clinical trials of our product candidates;

•

our ability to realize the anticipated benefits of our current or future research and development programs, strategic partnerships, licensing programs or other collaborations;

•

regulatory requirements or developments, and our ability to obtain necessary approvals from the U.S. Food and Drug Administration (the “FDA”) or other regulatory authorities;

•

our ability to manufacture product candidates in conformity with the FDA’s or other regulatory authorities’ requirements and to scale up manufacturing of our product candidates to commercial scale, if approved;

•

changes to clinical trial designs and regulatory pathways;

ii

•

developments and projections relating to our expected or existing competitors or industry;

•

legislative, regulatory, political, geopolitical and macroeconomic developments beyond our control, including inflationary pressures, general economic slowdown or a recession, high interest rates, changes in monetary policy or foreign currency exchange rates, changes in trade policies, including tariffs and other trade restrictions or the threat of such actions, instability in financial institutions, the ongoing conflict in Ukraine, conflicts in the Middle East, rising tensions between China and Taiwan, the attacks on marine vessels traversing the Red Sea and the responses thereto, volatility in oil and other commodity prices and supply chain disruptions;

•

success in retaining, recruiting or changes in, our officers, key employees or directors;

•

the liquidity and trading of our securities;

•

regulatory actions with respect to our product candidates or our competitors’ products and product candidates;

•

our ability to successfully develop and commercialize any technology that we have in-licensed or may in-license or products we have acquired or may acquire;

•

our ability to successfully operate in non-U.S. jurisdictions in which we may choose to do business, including compliance with applicable regulatory requirements and laws;

•

our reliance on third-party contract development and manufacturing organizations to manufacture and supply product candidates;

•

our ability to establish satisfactory pricing and obtain adequate reimbursement from government and third-party payors of our products and product candidates that receive regulatory approvals, if any;

•

our ability to successfully commercialize our product candidates, if approved, and the rate and degree of market acceptance of such product candidates;

•

risks related to our ability to obtain additional financing and raise capital as necessary to fund operations or pursue business opportunities;

•

our ability to continue to grow and manage our growth effectively; and

•

our ability to comply with, and the effect on our business of, evolving legal standards and regulations, including those concerning data protection, consumer privacy and sustainability and evolving labor standards.

There may be other factors that may cause our actual results or outcomes, or the timing of those results or outcomes, to differ materially from the forward-looking statements expressed or implied in this Quarterly Report on Form 10-Q, including factors disclosed in the sections titled “Risk Factors,” “Management’s Discussion and Analysis of Financial Condition and Results of Operations” and elsewhere in this Quarterly Report on Form 10-Q, in the section titled“Risk Factors”in our Annual Report on Form 10-K for the fiscal year ended December 31, 2025 and in our other filings with the Securities and Exchange Commission (the “SEC”). You should evaluate all forward-looking statements made in this Quarterly Report on Form 10-Q in the context of these risks and uncertainties.

We caution you that the risks, uncertainties and other factors referred to above and elsewhere in this Quarterly Report on Form 10-Q may not contain all of the risks, uncertainties and other factors that may affect our future results, operations and outcomes. Moreover, new risks emerge from time to time. It is not possible for us to predict all risks. In addition, we cannot assure you that we will realize the results, benefits or developments that we expect or anticipate or, even if substantially realized, that they will result in the consequences or affect us or our business in the way expected. Past performance is not indicative of future performance.

Any forward-looking statements contained in this Quarterly Report on Form 10-Q apply only as of the date of this Quarterly Report on Form 10-Q and are expressly qualified in their entirety by the cautionary statements included in this Quarterly Report on Form 10-Q. Except as required by law, we disclaim any intent to publicly update or revise any forward-looking statements, whether as a result of new information, future events, changes in assumptions or otherwise.

iii

Explanatory Note

Unless context otherwise requires, references to “we,” “our,” “us,” “Dianthus,” the “Company,” or the “combined company” in this Quarterly Report on Form 10-Q refer to Dianthus Therapeutics, Inc. (formerly Magenta Therapeutics, Inc.) for the period after the completion of the Reverse Merger (as defined below) and refer to Dianthus Therapeutics OpCo, Inc. for the period before the completion of the Reverse Merger. The term “Former Dianthus” also refers to Dianthus Therapeutics OpCo, Inc. (formerly Dianthus Therapeutics, Inc.), and the term “Magenta” refers to the Company prior to completion of the Reverse Merger. On September 11, 2023, we completed a business combination with Former Dianthus pursuant to which, among other matters, Former Dianthus became a wholly owned subsidiary of ours (the “Reverse Merger”).

iv