Peter A. Thompson - 12 Jun 2025 Form 4 Insider Report for Sionna Therapeutics, Inc. (SION)

Role: Director
Signature: Jennifer Fitzpatrick, Attorney-in-Fact
Issuer symbol: SION
Transactions as of: 12 Jun 2025
Net transactions value: $0
Form type: 4
Filing time: 16 Jun 2025, 17:08:24 UTC
Previous filing: 04 Apr 2025
Next filing: 18 Jun 2025
SEC: View on sec.gov

Reporting Owners (1)

Name	Relationship	Address	Signature	Signature date	CIK
Thompson Peter A.	Director	C/O SIONNA THERAPEUTICS, INC., 21 HICKORY DRIVE, SUITE 500, WALTHAM	Jennifer Fitzpatrick, Attorney-in-Fact	16 Jun 2025	0001357522

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	Pursuant to an agreement with OrbiMed Advisors LLC and OrbiMed Capital GP VIII LLC, the Reporting Person is obligated to transfer any securities issued under any such stock options or other awards, or the economic benefit thereof, to OrbiMed Advisors LLC and OrbiMed Capital GP VIII LLC, which will in turn ensure that such securities or economic benefits are provide to OrbiMed Private Investments VIII, LP.
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

Pursuant to an agreement with OrbiMed Advisors LLC and OrbiMed Capital GP VIII LLC, the Reporting Person is obligated to transfer any securities issued under any such stock options or other awards, or the economic benefit thereof, to OrbiMed Advisors LLC and OrbiMed Capital GP VIII LLC, which will in turn ensure that such securities or economic benefits are provide to OrbiMed Private Investments VIII, LP.

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.