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

Role: Director
Signature: Jennifer Fitzpatrick, Attorney-in-Fact
Stock symbol: SION
Transactions as of: Jun 12, 2025
Transactions value $: $0
Form type: 4
Date filed: 6/16/2025, 05:07 PM
Previous filing: Jun 6, 2025
Next filing: Jun 18, 2025
SEC: View on sec.gov

Reporting Owners (1)

Name	Relationship	Address	Signature	Signature date	CIK
Resnick Joshua	Director	C/O SIONNA THERAPEUTICS, INC., 21 HICKORY DRIVE, SUITE 500, WALTHAM	Jennifer Fitzpatrick, Attorney-in-Fact	2025-06-16	0001690959

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	+20K		$0.00	20K	Jun 12, 2025	Common Stock	20K	$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	Under the Reporting Person's arrangement with RA Capital Management, L.P. (the "Adviser"), the Reporting Person holds the option for the benefit of the RA Capital Healthcare Fund, L.P. (the "Fund"), the RA Capital Nexus Fund, L.P. (the "Nexus Fund"), the RA Capital Nexus Fund III, L.P. (the "Nexus Fund III"), and a separately managed account (the "Account"). The Reporting Person is obligated to turn over to the Adviser any net cash or stock received upon exercise of the stock option, which will offset advisory fees owed by the Fund, the Nexus Fund, the Nexus Fund III and the Account to the Adviser. The Reporting Person therefore disclaims beneficial ownership of the stock option and underlying Common Stock.
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

Under the Reporting Person's arrangement with RA Capital Management, L.P. (the "Adviser"), the Reporting Person holds the option for the benefit of the RA Capital Healthcare Fund, L.P. (the "Fund"), the RA Capital Nexus Fund, L.P. (the "Nexus Fund"), the RA Capital Nexus Fund III, L.P. (the "Nexus Fund III"), and a separately managed account (the "Account"). The Reporting Person is obligated to turn over to the Adviser any net cash or stock received upon exercise of the stock option, which will offset advisory fees owed by the Fund, the Nexus Fund, the Nexus Fund III and the Account to the Adviser. The Reporting Person therefore disclaims beneficial ownership of the stock option and underlying Common Stock.

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.