UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

__________________________

FORM 8-K

__________________________

CURRENT REPORT

Pursuant to Section 13 or 15(d)

of the Securities Exchange Act of 1934

Date of Report (date of earliest event reported): ~~May 12~~June 4, 2025

__________________________

SIONNA THERAPEUTICS, INC.

(Exact name of registrant as specified in its charter)

__________________________

Delaware

001-42504

84-2801521

(State or other jurisdiction

of incorporation)

(Commission

File Number)

(I.R.S. Employer

Identification No.)

Delaware			001-42504			84-2801521
(State or other jurisdictionof incorporation)			(CommissionFile Number)			(I.R.S. EmployerIdentification No.)

SIONNA THERAPEUTICS, INC.

21 Hickory Drive, Suite 500

Waltham, MA02451

(Address of principal executive offices, including zip code)

617-819-2020

(Registrant’s telephone number, including area code)

Not Applicable

(Former Name or Former Address, if Changed Since Last Report)

__________________________

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

☐	Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)

☐	Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)

☐	Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))

☐	Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

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

Title of each class

Trading Symbol(s)

Name of each exchange on which registered

~~TradingSymbol(s)~~

~~Name of each exchangeon which registered~~

Common Stock, $0.001 par value per share

SION

The Nasdaq Global Market

~~SION~~

~~The Nasdaq Global Market~~

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§ 230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§ 240.12b-2 of this chapter).

Emerging growth company x ☒

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. o ☐

Item 2 7.~~02 Results~~01 ofRegulation ~~Operations~~FD ~~and Financial Condition~~Disclosure.

On ~~May~~June 124, 2025, Sionna Therapeutics, Inc. issued a press release announcing data from its ~~financial~~Phase ~~results~~1 clinical trials of its product candidates SION-719 and ~~business~~SION-451, ~~highlights~~and its plans for ~~the~~future ~~three~~clinical ~~months~~development ~~ended~~of ~~March 31,~~these ~~2025~~product candidates. The full text of the press release is furnished as Exhibit 99.1 to this Current Report on Form 8-K.

The information set forth under this Item 27.0201 and in Exhibit 99.1 attached hereto is intended to be furnished and shall not be deemed “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), or otherwise subject to the liabilities of that section, nor shall it be deemed incorporated by reference in any filing under the Securities Act of 1933 or the Exchange Act, except as expressly set forth by specific reference in such filing.

Item 9.01

Financial Statements and Exhibits.

(d) Exhibits

99.1		Press Release of Sionna Therapeutics, Inc. dated June 4, 2025.	~~Press Release of Sionna Therapeutics, Inc. dated May 12, 2025.~~
104		Cover Page Interactive Data File (embedded within the Inline XBRL document).	~~Cover Page Interactive Data File (embedded within the Inline XBRL document).~~

SIGNATURE

Pursuant to the requirements of the Securities Exchange Act of 1934, as amended, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

			Sionna Therapeutics, Inc.
Date: May 12, 2025	By:		/s/ Jennifer Fitzpatrick
Date: June 4, 2025		By:	/s/ Jennifer Fitzpatrick
	~~Name:~~	Name:	Jennifer Fitzpatrick
	~~Title:~~	Title:	Chief Legal Officer

Filing Compare · Sionna Therapeutics, Inc.