Dianthus Therapeutics reported a net loss of $46.64 million

Item 6.

Exhibits

40

Signatures

41 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 complian

Item 1. Condensed Consolidated Financial Statements (Unaudited)

DIANTHUS THERAPEUTICS, INC.¹

Condensed Consolidated Balance Sheets (in thousands, except share and per share data) (unaudited)¹

September 30,¹

2026¹

December 31,

2025

Assets

Current assets:

Cash and cash equivalents²

$²

55,686²

$

51,087

Short-term investments²

782,097²

353,208

Accounts receivable, net

582

52

Prepaid expenses and other current assets

17,673

5,091

Total current assets

856,038

409,438

Long-term investments

406,040

110,135

Property and equipment, net

749

296

Right-of-use operating lease assets

1,151

1,337

Other assets and restricted cash

12,274

9,716

Total assets³

$³

1,276,252³

$

530,922

Liabilities and Stockholders' Equity

Current liabilities:

Accounts payable

$

5,498

$

9,725

Accrued expenses

21,079

19,452

Current portion of deferred revenue

1,589

1,188

Current portion of operating lease liabilities

349

367

Total current liabilities

28,515

30,732

Deferred revenue

5,449

5,770

Long-term operating lease liabilities

859

1,019

Total liabilities

34,823

37,521

Commitments and contingencies (Note 14)

Stockholders' equity:

—

—

respectively

56

43

Additional paid-in capital

1,722,069

829,598

Accumulated deficit

( 474,421

)

( 336,729

)

Accumulated other comprehensive (loss)/income

( 6,275

)

489

Total stockholders' equity

1,241,429

493,401

Total liabilities and stockholders' equity

$

1,276,252

$

530,922

The accompanying notes are an integral part of these unaudited condensed consolidated financial statements.

1

DIANTHUS THERAPEUTICS, INC.

Condensed Consolidated Statem ents of Operations and Comprehensive Loss (in thousands, except share and per share data) (unaudited)

Three Months Ended

September 30,

Nine Months Ended

September 30,

2026

2025

2026

2025

Revenues:

License revenue

$

1,210

$

396

$

2,434

$

1,752

Operating expenses:

Research and development⁵

45,600⁵

32,489

128,814

85,743

General and administrative⁵

14,082⁵

8,195

40,107

24,401

Total operating expenses

59,682

40,684

168,921

110,144

Loss from operations

( 58,472

)

( 40,288

)

( 166,487

)

( 108,392

)

Other income/(expense):

Interest and investment income

12,143

3,658

29,950

10,852

Gain/(loss) on investment in former related party

28

227

( 169

)

254

Loss on currency exchange, net

( 24

)

( 2

)

( 49

)

( 54

)

Other expense

( 318

)

( 360

)

( 937

)

( 565

)

Total other income

11,829

3,523

28,795

10,487

Net loss⁴

$⁴

( 46,643⁴

)⁴

$

( 36,765

)

$

( 137,692

)

$

( 97,905

)

Net loss per share attributable to common stockholders, basic and diluted

$

( 0.81

)

$

( 0.97

)

$

( 2.56

)

$

( 2.68

)

Weighted-average number of shares of common stock outstanding including shares issuable under equity-classified pre-funded warrants, used in computing net loss per share of common stock, basic and diluted

57,341,193

37,794,088

53,835,116

36,476,370

Comprehensive loss:

Net loss

$

( 46,643

)

$

( 36,765

)

$

( 137,692

)

$

( 97,905

)

Other comprehensive (loss)/income:

Unrealized (loss)/gain on marketable securities

( 4,147

)

65

( 6,764

)

57

Total other comprehensive (loss)/income

( 4,147

)

65

( 6,764

)

57

Total comprehensive loss

$

( 50,790

)

$

( 36,700

)

$

( 144,456

)

$

( 97,848

)

The accompanying notes are an integral part of these unaudited condensed consolidated financial statements.

2

DIANTHUS THERAPEUTICS, INC.

Condensed Consolidated Statements of Changes in Stockholders' Equity (in thousands, except share data) (unaudited)

Accumulated

Other

Total

Common Stock

Additional

Accumulated

Comprehensive

Stockholders'

Shares

Amount

Paid-in Capital

Deficit

(Loss)/Income

Equity

Balance, December 31, 2025

43,223,090

$

43

$

829,598

$

( 336,729

)

$

489

$

493,401

Issuance of common stock and pre-funded warrants in connection with public offering, net of issuance costs of $ 1,544

8,470,989

8

676,072

—

—

676,080

Issuance of common stock pursuant to at-the-market offering, net of issuance costs

1,123,126

1

58,730

—

—

58,731

Exercise of warrants and pre-funded warrants

1,004,580

1

—

—

—

1

Exercise of stock options (net of receivable for stock option proceeds in transit)

753,075

1

4,276

—

—

4,277

Issuance of common stock under employee stock purchase plan

7,889

—

120

—

—

120

Stock-based compensation expense

—

—

10,602

—

—

10,602

Net loss

—

—

—

( 40,834

)

—

( 40,834

)

Unrealized loss on marketable securities

—

—

—

—

( 1,064

)

( 1,064

)

Balance, March 31, 2026

54,582,749

$

54

$

1,579,398

$

( 377,563

)

$

( 575

)

$

1,201,314

Exercise of stock options (net of receivable for stock option proceeds in transit)

215,589

1

10,580

—

—

10,581

Stock-based compensation expense

—

—

11,898

—

—

11,898

Net loss⁶

—⁶

—⁶

—⁶

( 50,215⁶

)

—

( 50,215

)

Unrealized loss on marketable securities

—

—

—

—

( 1,553

)

( 1,553

)

Balance, June 30, 2026

54,798,338

$

55

$

1,601,876

$

( 427,778

)

$

( 2,128

)

$

1,172,025

Issuance of common stock pursuant to at-the-market offering, net of issuance costs

1,005,700

1

98,065

—

—

98,066

Exercise of stock options

483,956

—

9,163

—

—

9,163

Issuance of common stock under employee stock purchase plan

7,232

—

244

—

—

244

Stock-based compensation expense

—

—

12,721

—

—

12,721

Net loss

—

—

—

( 46,643

)

—

( 46,643

)

Unrealized loss on marketable securities

—

—

—

—

( 4,147

)

( 4,147

)

Balance, September 30, 2026

56,295,226

$

56

$

1,722,069

$

( 474,421

)

$

( 6,275

)

$

1,241,429

Balance, December 31, 2024

31,115,341

$

31

$

526,732

$

( 174,392

)

$

106

$

352,477

Exercise of pre-funded warrants

1,000,333

1

—

—

—

1

Exercise of stock options

3,321

—

31

—

—

31

Issuance of common stock under employee stock purchase plan

6,938

—

129

—

—

129

Stock-based compensation expense

—

—

5,315

—

—

5,315

Net loss

—

—

—

( 29,511

)

—

( 29,511

)

Unrealized