Sionna Therapeutics (SION) CMO receives 155,700 stock options grant

Rhea-AI Filing Summary

Sionna Therapeutics, Inc. reported that its Chief Medical Officer, Charlotte McKee, received a grant of a non-qualified stock option on January 2, 2026. The option covers 155,700 shares of common stock with an exercise price of $39.21 per share and an expiration date of January 1, 2036.

All 155,700 derivative securities are shown as beneficially owned directly following the transaction. According to the footnote, the shares underlying this option vest in 48 equal monthly installments after January 2, 2026, and each monthly vesting is conditioned on McKee’s continued service on the applicable vesting date.

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

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^*

McKee Charlotte

(Last) (First) (Middle)

C/O SIONNA THERAPEUTICS, INC.

21 HICKORY DRIVE, SUITE 500

(Street)

WALTHAM MA 02451

(City) (State) (Zip)

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

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

	Director		10% Owner
X	Officer (give title below)		Other (specify below)
	Chief Medical Officer

3. Date of Earliest Transaction (Month/Day/Year)
01/02/2026

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

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
Non-Qualified Stock Option (right to buy)	$39.21	01/02/2026		A		155,700		(1)	01/01/2036	Common Stock	155,700	$0.0	155,700	D

Explanation of Responses:

1. The shares underlying this option vest in forty-eight equal monthly installments following January 2, 2026, subject to the Reporting Person's continued service on each such vesting date.

	Jennifer Fitzpatrick, Attorney-in-Fact	01/06/2026
	** 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 insider transaction did SION disclose in this Form 4?

The filing shows that Sionna Therapeutics granted a non-qualified stock option to Chief Medical Officer Charlotte McKee on January 2, 2026, covering 155,700 shares of common stock.

Who is the reporting person in the SION Form 4 filing?

The reporting person is Charlotte McKee, who serves as Chief Medical Officer of Sionna Therapeutics, Inc.

How many options were granted to SION’s Chief Medical Officer and at what price?

Charlotte McKee was granted 155,700 non-qualified stock options with an exercise price of $39.21 per share.

When do the options granted to Charlotte McKee begin vesting and over what period?

The shares underlying the option vest in 48 equal monthly installments following January 2, 2026, with each installment subject to her continued service on the applicable vesting date.

When do the SION options granted to the CMO expire?

The non-qualified stock option granted to Charlotte McKee has an expiration date of January 1, 2036.

Are the SION options held directly or through another entity?

The Form 4 reports 155,700 derivative securities as directly beneficially owned by the reporting person following the transaction.