Sionna Therapeutics (SION) Form 3 Sionna Therapeutics / Elena Ridloff ownership change

SEC Form 3

FORM 3

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

INITIAL STATEMENT OF BENEFICIAL OWNERSHIP OF SECURITIES

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

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1. Name and Address of Reporting Person^*

Ridloff Elena

(Last) (First) (Middle)

SIONNA THERAPEUTICS, INC.

21 HICKORY DRIVE, SUITE 500

(Street)

WALTHAM MA 02451

(City) (State) (Zip)

2. Date of Event Requiring Statement (Month/Day/Year)
02/06/2025

3. Issuer Name and Ticker or Trading Symbol
Sionna Therapeutics, Inc. [ SION ]

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

	Director	10% Owner
X	Officer (give title below)	Other (specify below)
CFO & Head of Corp. Dev.

5. 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 Beneficially Owned
1. Title of Security (Instr. 4)	2. Amount of Securities Beneficially Owned (Instr. 4)	3. Ownership Form: Direct (D) or Indirect (I) (Instr. 5)	4. Nature of Indirect Beneficial Ownership (Instr. 5)
Common Stock	123,532	D

Table II - Derivative Securities Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 4)	2. Date Exercisable and Expiration Date (Month/Day/Year)		3. Title and Amount of Securities Underlying Derivative Security (Instr. 4)		4. Conversion or Exercise Price of Derivative Security	5. Ownership Form: Direct (D) or Indirect (I) (Instr. 5)	6. Nature of Indirect Beneficial Ownership (Instr. 5)
	Date Exercisable	Expiration Date	Title	Amount or Number of Shares
Stock Option (Right to Buy)	(1)	09/16/2031	Common Stock	32,509	0.78	D
Stock Option (Right to Buy)	(2)	03/01/2032	Common Stock	109,605	6.11	D
Stock Option (Right to Buy)	(3)	03/12/2034	Common Stock	145,751	6.11	D

Explanation of Responses:

1. 25% of the shares underlying this option vested on September 14, 2022, with the remainder vesting in thirty-six equal monthly installments thereafter, subject to the Reporting Person's continued service on each such vesting date.

2. The shares underlying this option vest in forty-eight equal monthly installments following February 2, 2022, subject to the Reporting Person's continued service on each such vesting date.

3. The shares underlying this option vest in forty-eight equal monthly installments following March 4, 2024, subject to the Reporting Person's continued service on each such vesting date.

Remarks:

Exhibit 24 - Power of Attorney.

	/s/ Jennifer Fitzpatrick, Attorney-in-Fact	02/06/2025
	** 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 5 (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).
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