Sirenia discloses 3.1% stake in Dianthus Therapeutics

Sirenia Capital Management LP and Alex Silverstein report beneficial ownership of 1,696,751 shares of Dianthus Therapeutics, Inc. common stock, including 510,400 shares issuable upon exercise of call options.

Rhea-AI Filing Summary

Sirenia Capital Management LP and Alex Silverstein report beneficial ownership of 1,696,751 shares of Dianthus Therapeutics, Inc. common stock, including 510,400 shares issuable upon exercise of call options. This represents 3.1% of the company’s 54,666,233 shares outstanding as of May 1, 2026.

The reporting persons have shared voting and dispositive power over all reported shares and no sole voting or dispositive power. The filing is an amendment to a Schedule 13G and confirms ownership of less than 5% of the class.

Key Figures

Shares beneficially owned: 1,696,751 shares Percent of class: 3.1% Shares outstanding: 54,666,233 shares +2 more

5 metrics

Shares beneficially owned 1,696,751 shares Beneficial ownership reported jointly by Sirenia Capital Management LP and Alex Silverstein

Percent of class 3.1% Percentage of Dianthus Therapeutics common stock outstanding as of May 1, 2026

Shares outstanding 54,666,233 shares Common stock outstanding as of May 1, 2026, per the issuer’s Form 10-Q

Shares issuable via call options 510,400 shares Portion of beneficial ownership represented by shares issuable upon exercise of call options

Shared voting power 1,696,751 shares Shares over which the reporting persons have shared voting and dispositive power

Key Terms

beneficial owner, shared voting power, shared dispositive power, Schedule 13G, +1 more

5 terms

beneficial owner regulatory

"for the purposes of Section 13 of the Securities Exchange Act of 1934, the beneficial owner"

A beneficial owner is the person who ultimately owns or controls a financial asset or property, even if their name isn't directly on official documents. Think of it like someone who secretly holds the keys to a safe deposit box—others may appear to have access, but the true owner is the one who benefits from what's inside. Identifying beneficial owners helps ensure transparency and prevent illegal activities like money laundering or fraud.

shared voting power regulatory

"Shared Voting Power 1,696,751.00"

Shared voting power occurs when two or more parties jointly have the right to vote or decide how a block of company shares is cast, like co-owners who must agree before moving a piece of furniture. Investors care because who controls voting rights affects board elections, major corporate decisions and takeover outcomes, and shared control can alter regulatory disclosures and the practical influence any holder has over a company’s direction and value.

shared dispositive power regulatory

"Shared Dispositive Power 1,696,751.00"

Schedule 13G regulatory

"This statement is filed by... The filing of this statement should not be construed"

A Schedule 13G is a formal document that investors file with the government when they acquire a large ownership stake in a company, usually for investment purposes rather than control. It helps keep the public informed about who owns significant parts of a company's shares, which can influence how the company is managed and how investors make decisions. Filing this schedule is important for transparency and understanding the ownership landscape of publicly traded companies.

call options financial

"Includes 510,400 shares of Common Stock issuable upon exercise of call options"

A call option is a contract that gives its buyer the right, but not the obligation, to buy a specific number of shares at a predetermined price within a set time. Think of it like a refundable reservation to purchase a stock later at today’s agreed price: investors use calls to profit from expected price rises with smaller upfront cost than buying the stock outright, or to hedge and manage exposure, while the most they can lose is the amount paid for the contract.

FAQ

AI-generated questions and answers. How Rhea-AI works. Not financial advice.

What percentage of Dianthus Therapeutics (DNTH) does Sirenia Capital own?

Sirenia Capital Management and Alex Silverstein report beneficial ownership of 3.1% of Dianthus Therapeutics’ common stock, based on 54,666,233 shares outstanding as of May 1, 2026, as stated in the company’s Form 10-Q.

How many Dianthus Therapeutics (DNTH) shares are reported by Sirenia Capital?

The reporting persons disclose beneficial ownership of 1,696,751 shares of Dianthus Therapeutics common stock, which includes 510,400 shares issuable upon exercise of call options held by funds and an account managed by Sirenia.

Does Sirenia Capital hold Dianthus Therapeutics (DNTH) shares directly or through options?

Sirenia’s reported position includes both stock and derivatives: 1,696,751 total shares of beneficial ownership, of which 510,400 shares are issuable upon exercise of call options held by the Sirenia funds and a managed account.

What voting power does Sirenia Capital have over Dianthus Therapeutics (DNTH) shares?

The reporting persons state they have shared voting power and shared dispositive power over 1,696,751 shares, and no sole voting or dispositive power over any Dianthus Therapeutics common stock reported in this Schedule 13G/A.

Why is this Dianthus Therapeutics (DNTH) holding reported on Schedule 13G/A?

The position is reported on an amended Schedule 13G because the reporting persons are disclosing beneficial ownership of less than 5% of the class of Dianthus Therapeutics common stock, consistent with the passive ownership disclosure framework.

Who are the reporting persons in the Dianthus Therapeutics (DNTH) Schedule 13G/A?

The filing identifies Sirenia Capital Management LP and Alex Silverstein. Sirenia reports on shares held by its managed funds and account, and Mr. Silverstein reports as managing member of the general partner of Sirenia.

AI-generated analysis. How Rhea-AI works. Not financial advice.

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Available on EDGAR 08/14/2026 - 08:33 AM Accepted by SEC EDGAR 08/14/2026 - 08:33 AM Learn about SEC filing dates

SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

SCHEDULE 13G

UNDER THE SECURITIES EXCHANGE ACT OF 1934

(Amendment No. 1)

Dianthus Therapeutics, Inc. /DE/

(Name of Issuer)

Common Stock, par value $0.001 per share

(Title of Class of Securities)

(CUSIP Number)

06/30/2026

(Date of Event Which Requires Filing of this Statement)

Check the appropriate box to designate the rule pursuant to which this Schedule is filed:

Rule 13d-1(b)

Rule 13d-1(c)

Rule 13d-1(d)

schemaVersion:

SCHEDULE 13G

CUSIP No.

1

Names of Reporting Persons

Sirenia Capital Management LP

2

Check the appropriate box if a member of a Group (see instructions)

(a)
(b)

3

Sec Use Only

4

Citizenship or Place of Organization

DELAWARE

Number of Shares Beneficially Owned by Each Reporting Person With:

5	Sole Voting Power 0.00
6	Shared Voting Power 1,696,751.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 1,696,751.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

1,696,751.00

10

Check box if the aggregate amount in row (9) excludes certain shares (See Instructions)

11

Percent of class represented by amount in row (9)

3.1 %

12

Type of Reporting Person (See Instructions)

IA, PN

Comment for Type of Reporting Person: Includes 510,400 shares of Common Stock (as defined in Item 2(a)) issuable upon exercise of call options.

SCHEDULE 13G

CUSIP No.

1

Names of Reporting Persons

Alex Silverstein

2

Check the appropriate box if a member of a Group (see instructions)

(a)
(b)

3

Sec Use Only

4

Citizenship or Place of Organization

UNITED STATES

Number of Shares Beneficially Owned by Each Reporting Person With:

5	Sole Voting Power 0.00
6	Shared Voting Power 1,696,751.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 1,696,751.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

1,696,751.00

10

Check box if the aggregate amount in row (9) excludes certain shares (See Instructions)

11

Percent of class represented by amount in row (9)

3.1 %

12

Type of Reporting Person (See Instructions)

HC, IN

Comment for Type of Reporting Person: Includes 510,400 shares of Common Stock issuable upon exercise of call options.

SCHEDULE 13G

Item 1.
(a)	Name of issuer: Dianthus Therapeutics, Inc. /DE/
(b)	Address of issuer's principal executive offices: 7 Times Square, 43rd Floor, New York, New York 10036
Item 2.
(a)	Name of person filing: This statement is filed by: (i) Sirenia Capital Management LP ("Sirenia") with respect to the common stock, par value $0.001 per share ("Common Stock"), of Dianthus Therapeutics, Inc. (the "Issuer") held by (and underlying options held by) investment funds it manages (the "Sirenia Funds") and a managed account it manages (the "Sirenia Account"); and (ii) Alex Silverstein ("Mr. Silverstein"), the managing member of Sirenia Capital Management GP LLC, the general partner of Sirenia, with respect to the Common Stock held by (and underlying options held by) the Sirenia Funds and the Sirenia Account. The foregoing persons are hereinafter sometimes collectively referred to as the "Reporting Persons." The filing of this statement should not be construed as an admission that any of the foregoing persons or any Reporting Person is, for the purposes of Section 13 of the Securities Exchange Act of 1934, the beneficial owner of the securities reported herein
(b)	Address or principal business office or, if none, residence: The address of the principal business office of Sirenia and Mr. Silverstein is 1674 Meridian Avenue, Suite 320, Miami Beach, FL 33139.
(c)	Citizenship: Sirenia is a Delaware limited partnership. Mr. Silverstein is a United States citizen.
(d)	Title of class of securities: Common Stock, par value $0.001 per share
(e)	CUSIP No.:
Item 3.	If this statement is filed pursuant to §§ 240.13d-1(b) or 240.13d-2(b) or (c), check whether the person filing is a:
(a)	Broker or dealer registered under section 15 of the Act (15 U.S.C. 78o);
(b)	Bank as defined in section 3(a)(6) of the Act (15 U.S.C. 78c);
(c)	Insurance company as defined in section 3(a)(19) of the Act (15 U.S.C. 78c);
(d)	Investment company registered under section 8 of the Investment Company Act of 1940 (15 U.S.C. 80a-8);
(e)	An investment adviser in accordance with § 240.13d-1(b)(1)(ii)(E);
(f)	An employee benefit plan or endowment fund in accordance with § 240.13d-1(b)(1)(ii)(F);
(g)	A parent holding company or control person in accordance with § 240.13d-1(b)(1)(ii)(G);
(h)	A savings associations as defined in Section 3(b) of the Federal Deposit Insurance Act (12 U.S.C. 1813);
(i)	A church plan that is excluded from the definition of an investment company under section 3(c)(14) of the Investment Company Act of 1940 (15 U.S.C. 80a-3);
(j)	A non-U.S. institution in accordance with § 240.13d-1(b)(1)(ii)(J). If filing as a non-U.S. institution in accordance with § 240.13d-1(b)(1)(ii)(J), please specify the type of institution:
(k)	Group, in accordance with Rule 240.13d-1(b)(1)(ii)(K).
Item 4.	Ownership
(a)	Amount beneficially owned: The information required by Item 4(a) is set forth in Row 9 of the cover page for each of the Reporting Persons and is incorporated herein by reference. The percentage set forth in this Schedule 13G is calculated based upon an aggregate of 54,666,233 shares of Common Stock outstanding as of May 1, 2026, as reported in the Issuer's Quarterly Report on Form 10-Q for the quarterly period of March 31, 2026, filed with the Securities and Exchange Commission on May 5, 2026.
(b)	Percent of class: 3.1%
(c)	Number of shares as to which the person has:
	(i) Sole power to vote or to direct the vote: The information required by Item 4(c)(i) is set forth in Row 5 of the cover page for each of the Reporting Persons and is incorporated herein by reference.
	(ii) Shared power to vote or to direct the vote: The information required by Item 4(c)(ii) is set forth in Row 6 of the cover page for each of the Reporting Persons and is incorporated herein by reference.
	(iii) Sole power to dispose or to direct the disposition of: The information required by Item 4(c)(iii) is set forth in Row 7 of the cover page for each of the Reporting Persons and is incorporated herein by reference.
	(iv) Shared power to dispose or to direct the disposition of: The information required by Item 4(c)(iv) is set forth in Row 8 of the cover page for each of the Reporting Persons and is incorporated herein by reference.
Item 5.	Ownership of 5 Percent or Less of a Class.
	Ownership of 5 percent or less of a class
Item 6.	Ownership of more than 5 Percent on Behalf of Another Person.
	If any other person is known to have the right to receive or the power to direct the receipt of dividends from, or the proceeds from the sale of, such securities, a statement to that effect should be included in response to this item and, if such interest relates to more than 5 percent of the class, such person should be identified. A listing of the shareholders of an investment company registered under the Investment Company Act of 1940 or the beneficiaries of employee benefit plan, pension fund or endowment fund is not required. See Item 2(a).
Item 7.	Identification and Classification of the Subsidiary Which Acquired the Security Being Reported on by the Parent Holding Company or Control Person.
	If a parent holding company has filed this schedule, pursuant to Rule 13d-1(b)(ii)(G), so indicate under Item 3(g) and attach an exhibit stating the identity and the Item 3 classification of the relevant subsidiary. If a parent holding company has filed this schedule pursuant to Rule 13d-1(c) or Rule 13d-1(d), attach an exhibit stating the identification of the relevant subsidiary. See Item 2(a) and Item 3.
Item 8.	Identification and Classification of Members of the Group.
	Not Applicable
Item 9.	Notice of Dissolution of Group.
	Not Applicable

Item 10.

Certifications:

By signing below I certify that, to the best of my knowledge and belief, the securities referred to above were acquired and are held in the ordinary course of business and were not acquired and are not held for the purpose of or with the effect of changing or influencing the control of the issuer of the securities and were not acquired and are not held in connection with or as a participant in any transaction having that purpose or effect, other than activities solely in connection with a nomination under § 240.14a-11.

SIGNATURE

After reasonable inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct.

Sirenia Capital Management LP

Signature:	/s/ Kolby Loft
Name/Title:	Kolby Loft, General Counsel & Chief Compliance Officer
Date:	08/14/2026

Alex Silverstein

Signature:	/s/ Alex Silverstein
Name/Title:	Alex Silverstein, individually
Date:	08/14/2026