Dianthus Therapeutics reported that Sirenia Capital Management and Alex Silverstein together hold 2,798,122 shares, representing 5.3% of the outstanding common stock. The filing states the outstanding share count used for the percentage was 52,942,083 shares (aggregate basis).
The reported position includes 500,000 shares issuable upon exercise of call options. The disclosure is made via a joint Schedule 13G filing under Rule 13d-1(k).
Positive
None.
Negative
None.
Insights
Sirenia and its manager report a passive 5.3% stake in Dianthus.
The statement lists 2,798,122 shares and a 5.3% ownership percentage calculated from an aggregate share base of 52,942,083 shares. It explicitly notes inclusion of 500,000 shares issuable on option exercise.
Investor relations should note this is a Schedule 13G joint filing under Rule 13d-1(k), which typically signals passive intent; subsequent filings would reveal any change in intent or activity.
Filing appears procedurally standard and includes a Joint Filing Agreement.
The disclosure attributes shared voting and dispositive power of 2,798,122 shares to Sirenia and Mr. Silverstein and references a Joint Filing Agreement (Exhibit 99.1). The calculation cites specific issuance events and dates for the outstanding share base.
Compliance should retain the filing and monitor for any Schedule 13D or Form 4 that would indicate an active intent or change in ownership classification.
Key Figures
Shares beneficially owned:2,798,122 sharesPercent of class:5.3%Shares outstanding (basis):52,942,083 shares+1 more
4 metrics
Shares beneficially owned2,798,122 sharesreported combined holding by Sirenia and Alex Silverstein
Percent of class5.3%percentage of total outstanding stock used by filers
Shares outstanding (basis)52,942,083 sharesaggregate outstanding share count used to calculate 5.3% (as described in Item 4)
Options included500,000 sharesshares issuable upon exercise of call options included in the reported total
"This statement is filed by: (i) Sirenia Capital Management LP"
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.
Joint Filing Agreementregulatory
"Sirenia and Mr. Silverstein have entered into a Joint Filing Agreement"
beneficially ownedfinancial
"Amount beneficially owned: The information required by Item 4(a)"
Beneficially owned describes securities or assets where a person has the economic rights and control—such as the right to receive dividends and to direct voting—even if legal title is held in another name. Think of it like having the keys and using a car that’s registered to someone else: you get the benefits and make decisions. Investors care because beneficial ownership reveals who truly controls value and voting power, affecting corporate decisions and takeover dynamics.
shared dispositive powerfinancial
"Shared Dispositive Power 2,798,122.00"
call optionsfinancial
"Includes 500,000 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.
What stake does Sirenia Capital report in Dianthus (DNTH)?
Sirenia and Alex Silverstein report ownership of 2,798,122 shares, or 5.3%. The percentage is calculated using an aggregate outstanding share base of 52,942,083 shares as described in the filing's Item 4 accounting.
Does the reported 2,798,122 share position include options?
Yes. The filing states the position includes 500,000 shares issuable upon exercise of call options, which the reporting persons counted toward their reported total share figure.
What filing type did Sirenia use to disclose this holding?
The disclosure was made on a Schedule 13G filed under Rule 13d-1(k) as a joint filing. The submission includes a Joint Filing Agreement as Exhibit 99.1 signed by the reporting persons.
How was the 5.3% ownership percentage calculated?
The percentage uses an aggregate of 52,942,083 shares outstanding. That total combines recent prospectus issuances, an overallotment exercise, and the issuer's reported outstanding shares as of March 4, 2026.
Who signed the Schedule 13G for the reporting parties?
The filing is signed by Kolby Loft as General Counsel & CCO and by Alex Silverstein individually. The signature block shows execution dates of 05/15/2026 for both signatories.
SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549
SCHEDULE 13G
UNDER THE SECURITIES EXCHANGE ACT OF 1934
Dianthus Therapeutics, Inc. /DE/
(Name of Issuer)
Common Stock, par value $0.001 per share
(Title of Class of Securities)
252828108
(CUSIP Number)
03/31/2026
(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 Number(s):
252828108
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
2,798,122.00
7
Sole Dispositive Power
0.00
8
Shared Dispositive Power
2,798,122.00
9
Aggregate Amount Beneficially Owned by Each Reporting Person
2,798,122.00
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)
5.3 %
12
Type of Reporting Person (See Instructions)
IA, PN
Comment for Type of Reporting Person: Includes 500,000 shares of Common Stock (as defined in Item 2(a)) issuable upon exercise of call options.
SCHEDULE 13G
CUSIP Number(s):
252828108
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
2,798,122.00
7
Sole Dispositive Power
0.00
8
Shared Dispositive Power
2,798,122.00
9
Aggregate Amount Beneficially Owned by Each Reporting Person
2,798,122.00
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)
5.3 %
12
Type of Reporting Person (See Instructions)
HC, IN
Comment for Type of Reporting Person: Includes 500,000 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) an investment fund (the "Sirenia Fund") and managed account (the "Sirenia Account") it manages; 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 Fund and 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.
Sirenia and Mr. Silverstein have entered into a Joint Filing Agreement, a copy of which is filed with this Schedule 13G as Exhibit 99.1, pursuant to which they have agreed to file this Schedule 13G jointly in accordance with the provisions of Rule 13d-1(k) of the Securities Exchange Act of 1934 (the "Act").
(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 Number(s):
252828108
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 52,942,083 shares of Common Stock outstanding, which is the sum of (i) 7,313,582 shares of Common Stock issued in the offering described in the Issuer's Prospectus filed pursuant to Rule 424(b)(5) with the Securities and Exchange Commission (the "SEC") on March 11, 2026; (ii) 1,157,407 shares of Common Stock issued pursuant to the exercise of the underwriters' overallotment option as reported in the Issuer's Current Report on Form 8-K filed with the SEC on March 12, 2026; and (iii) 44,471,094 shares of Common Stock outstanding as of March 4, 2026, as reported in the Issuer's Annual Report on Form 10-K for the fiscal year ended December 31, 2025, filed with the SEC on March 9, 2026.
(b)
Percent of class:
5.3%
(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.
Not Applicable
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.
Not Applicable
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
