Bruce Booth - 12 Jun 2025 Form 4 Insider Report for Sionna Therapeutics, Inc. (SION)

Role: Director
Signature: Ommer Chohan, Attorney-in-Fact
Issuer symbol: SION
Transactions as of: 12 Jun 2025
Net transactions value: $0
Form type: 4
Filing time: 16 Jun 2025, 17:06:39 UTC
Previous filing: 23 May 2025
Next filing: 26 Jun 2025
SEC: View on sec.gov

Reporting Owners (1)

Name	Relationship	Address	Signature	Signature date	CIK
Booth Bruce	Director	C/O SIONNA THERAPEUTICS, INC., 21 HICKORY DRIVE, SUITE 500, WALTHAM	Ommer Chohan, Attorney-in-Fact	16 Jun 2025	0001451612

Derivative Securities (e.g., puts, calls, warrants, options, convertible securities)

Type	Sym	Class	Transaction	Value $	Shares	Change %	* Price $	Shares After	Date	Underlying Class	Amount	Exercise Price	Ownership	Footnotes
transaction	SION	Non-Qualified Stock Option (right to buy)	Award	$0	+19,959		$0.000000	19,959	12 Jun 2025	Common Stock	19,959	$16.99	Direct	F1, F2

* An asterisk sign (*) next to the price indicates that the price is likely invalid.

Explanation of Responses:

Id	Content
F1	This option was granted to the Reporting Person, a director of the Issuer. The proceeds of any sale of shares of common stock issued to the Reporting Person upon exercise of this option will be transferred to Atlas Venture Life Science Advisors, LLC and as such, the Reporting Person disclaims ownership of such securities reported herein for purposes of Section 16 of the Securities Exchange Act of 1934, as amended, except to the extent of his pecuniary interest therein, if any.
F2	This option vests in full upon the earlier of June 12, 2026 or the date of the next annual meeting of Sionna Therapeutics, Inc., subject to the Reporting Person's continued service on such vesting date.

Content

This option was granted to the Reporting Person, a director of the Issuer. The proceeds of any sale of shares of common stock issued to the Reporting Person upon exercise of this option will be transferred to Atlas Venture Life Science Advisors, LLC and as such, the Reporting Person disclaims ownership of such securities reported herein for purposes of Section 16 of the Securities Exchange Act of 1934, as amended, except to the extent of his pecuniary interest therein, if any.

This option vests in full upon the earlier of June 12, 2026 or the date of the next annual meeting of Sionna Therapeutics, Inc., subject to the Reporting Person's continued service on such vesting date.