Dianthus Therapeutics (DNTH) CEO sells 122,918 shares after option exercise

Rhea-AI Filing Summary

Dianthus Therapeutics CEO Garcia Marino reported an option exercise and related share sales. On March 12, 2026, he exercised stock options for 122,918 shares of common stock at an exercise price of $6.70 per share. The same day, he sold 122,918 shares of common stock in multiple open-market transactions at prices ranging from about $80.69 to $85.53 per share. The filing states the transactions were effected under a Rule 10b5-1 trading plan adopted on November 17, 2025. Following these transactions, he reported no directly held common shares and no remaining derivative position from this option grant.

Insights

Equity analyst

CEO exercises options, then fully sells the acquired shares under a pre-set trading plan.

Garcia Marino, CEO of Dianthus Therapeutics, exercised stock options for 122,918 common shares at an exercise price of $6.70 per share. This converted an existing derivative award into stock and is a typical compensation-related event.

On the same day, he sold 122,918 common shares in several open-market trades at prices from $80.69 to $85.53 per share. A footnote explains these sales were made under a Rule 10b5-1 trading plan adopted on November 17, 2025, indicating they were pre-scheduled rather than opportunistic.

After these transactions, he reported holding no common shares directly, and the derivative summary shows no remaining position from this option grant. The filing shows a complete exercise-and-sell sequence; how significant this is depends on his broader equity exposure not visible in this single report.

SEC Form 4

FORM 4

UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934
or Section 30(h) of the Investment Company Act of 1940

OMB APPROVAL

OMB Number:			3235-0287
Estimated average burden
hours per response:			0.5

Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

X

Check this box to indicate that a transaction was made pursuant to a contract, instruction or written plan for the purchase or sale of equity securities of the issuer that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c). See Instruction 10.

1. Name and Address of Reporting Person^*

Garcia Marino

(Last) (First) (Middle)

C/O DIANTHUS THERAPEUTICS, INC.

7 TIMES SQUARE, 43RD FLOOR

(Street)

NEW YORK NY 10036

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
Dianthus Therapeutics, Inc. /DE/ [ DNTH ]

5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)

X	Director		10% Owner
X	Officer (give title below)		Other (specify below)
	CEO AND PRESIDENT

3. Date of Earliest Transaction (Month/Day/Year)
03/12/2026

4. If Amendment, Date of Original Filed (Month/Day/Year)

6. Individual or Joint/Group Filing (Check Applicable Line)

X	Form filed by One Reporting Person
	Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	3. Transaction Code (Instr. 8)		4. Securities Acquired (A) or Disposed Of (D) (Instr. 3, 4 and 5)			5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4)	6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
			Code	V	Amount	(A) or (D)	Price
Common Stock	03/12/2026		M(1)		122,918	A	$6.7	122,918	D
Common Stock	03/12/2026		S(1)		43,505	D	$80.69(2)	79,413	D
Common Stock	03/12/2026		S(1)		65,517	D	$81.74(3)	13,896	D
Common Stock	03/12/2026		S(1)		12,796	D	$82.6(4)	1,100	D
Common Stock	03/12/2026		S(1)		200	D	$83.38	900	D
Common Stock	03/12/2026		S(1)		900	D	$85.53	0	D

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Transaction Date (Month/Day/Year)	3A. Deemed Execution Date, if any (Month/Day/Year)	4. Transaction Code (Instr. 8)		5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5)		6. Date Exercisable and Expiration Date (Month/Day/Year)		7. Title and Amount of Securities Underlying Derivative Security (Instr. 3 and 4)		8. Price of Derivative Security (Instr. 5)	9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)	10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
				Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares
Stock Option (Right to Buy)	$6.7	03/12/2026		M(1)			122,918	(5)	11/03/2031	Common Stock	122,918	$0	59,741	D

Explanation of Responses:

1. The reported transaction was effected pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on November 17, 2025.

2. The price reported above is a weighted average price. The shares were sold in multiple transactions at prices ranging from $80.29 to $81.28, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the SEC, upon request, full information regarding the number of shares sold at each separate price within the range.

3. The price reported above is a weighted average price. The shares were sold in multiple transactions at prices ranging from $81.29 to $82.25, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the SEC, upon request, full information regarding the number of shares sold at each separate price within the range.

4. The price reported above is a weighted average price. The shares were sold in multiple transactions at prices ranging from $82.29 to $83.23, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the SEC, upon request, full information regarding the number of shares sold at each separate price within the range.

5. The shares of common stock underlying this stock option award vested as to 25% of the shares on November 1, 2022, with the remaining three quarters vested in equal monthly installments over the following three years, subject to the Reporting Person's continued service to the Issuer on each such vesting date.

	/s/ Adam Veness, as attorney-in-fact for Marino Garcia	03/13/2026
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 4 (b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.

FAQ

What did Dianthus Therapeutics (DNTH) CEO Garcia Marino report in this Form 4?

He reported exercising stock options for 122,918 shares of Dianthus Therapeutics common stock at $6.70 per share and then selling 122,918 shares in multiple open-market transactions on the same date.

At what prices did the Dianthus Therapeutics (DNTH) CEO sell his shares?

He sold 122,918 shares of Dianthus common stock in several trades at prices ranging from about $80.69 to $85.53 per share, according to the transaction detail in the Form 4.

Was the Dianthus Therapeutics (DNTH) CEO’s stock sale under a Rule 10b5-1 plan?

Yes. A footnote states the reported transaction was effected under a Rule 10b5-1 trading plan adopted by Garcia Marino on November 17, 2025, indicating the sales were pre-arranged in advance.

How many shares did the Dianthus Therapeutics (DNTH) CEO hold after these transactions?

After the sequence of option exercise and open-market sales, the Form 4 shows Garcia Marino with 0 shares of common stock held directly following the final reported transaction on March 12, 2026.

What derivative securities did the Dianthus Therapeutics (DNTH) CEO exercise?

He exercised a stock option covering 122,918 shares of common stock at an exercise price of $6.70 per share. The option was originally scheduled to vest over several years, as described in an accompanying footnote.

Does the Form 4 show any remaining stock options for the Dianthus Therapeutics (DNTH) CEO?

For this specific option grant, the filing reports an exercise of 122,918 shares and shows no remaining derivative position in the derivative summary, indicating this award was fully exercised in the reported transaction.