Ra Capital Management Form 4 Sionna Therapeutics / Peter Kolchinsky ownership change

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

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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).

1. Name and Address of Reporting Person^*

RA CAPITAL MANAGEMENT, L.P.

(Last) (First) (Middle)

200 BERKELEY STREET, 18TH FLOOR

(Street)

BOSTON MA 02116

(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)

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

3. Date of Earliest Transaction (Month/Day/Year)
02/10/2025

4. If Amendment, Date of Original Filed (Month/Day/Year)

6. Individual or Joint/Group Filing (Check Applicable Line)

	Form filed by One Reporting Person
X	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
Common Stock	02/10/2025		C		5,021,990	A	(1)	5,900,779	I	See footnotes(2)(3)
Common Stock	02/10/2025		C		527,444	A	(1)	869,651	I	See footnotes(3)(4)
Common Stock	02/10/2025		C		2,222,084	A	(1)	2,222,084	I	See footnotes(3)(5)
Common Stock	02/10/2025		C		179,975	A	(1)	327,808	I	See footnotes(3)(6)
Common Stock	02/10/2025		P		1,022,586	A	$18	6,923,365	I	See footnotes(2)(3)
Common Stock	02/10/2025		P		102,414	A	$18	2,324,498	I	See footnotes(3)(5)

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
Series Seed Preferred Stock	(1)	02/10/2025		C			819,153	(1)	(1)	Common Stock	560,642	$0	0	I	See footnotes(2)(3)
Series Seed Preferred Stock	(1)	02/10/2025		C			319,069	(1)	(1)	Common Stock	218,375	$0	0	I	See footnotes(3)(4)
Series Seed Preferred Stock	(1)	02/10/2025		C			138,054	(1)	(1)	Common Stock	94,486	$0	0	I	See footnotes(3)(6)
Series A Preferred Stock	(1)	02/10/2025		C			1,229,830	(1)	(1)	Common Stock	841,716	$0	0	I	See footnotes(2)(3)
Series A Preferred Stock	(1)	02/10/2025		C			451,580	(1)	(1)	Common Stock	309,069	$0	0	I	See footnotes(3)(4)
Series A Preferred Stock	(1)	02/10/2025		C			124,908	(1)	(1)	Common Stock	85,489	$0	0	I	See footnotes(3)(6)
Series B Preferred Stock	(1)	02/10/2025		C			923,773	(1)	(1)	Common Stock	632,244	$0	0	I	See footnotes(2)(3)
Series B Preferred Stock	(1)	02/10/2025		C			2,155,469	(1)	(1)	Common Stock	1,475,237	$0	0	I	See footnotes(3)(5)
Series C Preferred Stock	(1)	02/10/2025		C			4,364,874	(1)	(1)	Common Stock	2,987,388	$0	0	I	See footnotes(2)(3)
Series C Preferred Stock	(1)	02/10/2025		C			1,091,219	(1)	(1)	Common Stock	746,847	$0	0	I	See footnotes(3)(5)

1. Name and Address of Reporting Person^*

RA CAPITAL MANAGEMENT, L.P.

(Last) (First) (Middle)

200 BERKELEY STREET, 18TH FLOOR

(Street)

BOSTON MA 02116

(City) (State) (Zip)

1. Name and Address of Reporting Person^*

RA Capital Healthcare Fund LP

(Last) (First) (Middle)

C/O RA CAPITAL MANAGEMENT, L.P.

200 BERKELEY STREET, 18TH FLOOR

(Street)

BOSTON MA 02116

(City) (State) (Zip)

1. Name and Address of Reporting Person^*

RA Capital Nexus Fund, L.P.

(Last) (First) (Middle)

C/O RA CAPITAL MANAGEMENT, L.P.

200 BERKELEY STREET, 18TH FLOOR

(Street)

BOSTON MA 02116

(City) (State) (Zip)

1. Name and Address of Reporting Person^*

RA Capital Nexus Fund III, L.P.

(Last) (First) (Middle)

C/O RA CAPITAL MANAGEMENT, L.P.

200 BERKELEY STREET, 18TH FLOOR

(Street)

BOSTON MA 02116

(City) (State) (Zip)

1. Name and Address of Reporting Person^*

Kolchinsky Peter

(Last) (First) (Middle)

C/O RA CAPITAL MANAGEMENT, L.P.

200 BERKELEY STREET, 18TH FLOOR

(Street)

BOSTON MA 02116

(City) (State) (Zip)

1. Name and Address of Reporting Person^*

Shah Rajeev M.

(Last) (First) (Middle)

C/O RA CAPITAL MANAGEMENT, L.P.

200 BERKELEY STREET, 18TH FLOOR

(Street)

BOSTON MA 02116

(City) (State) (Zip)

Explanation of Responses:

1. Each share of Series Seed Preferred Stock, Series A Preferred Stock, Series B Preferred Stock, and Series C Preferred Stock (collectively the "Preferred Stock") converted into shares of Common Stock of the Issuer on a one-for-1.4611 basis upon the closing of the Issuer's initial public offering without payment of further consideration. The Preferred Stock had no expiration date.

2. Held directly by RA Capital Healthcare Fund, L.P. (the "Fund").

3. RA Capital Management, L.P. (the "Adviser") is the investment manager for the Fund, RA Capital Nexus Fund, L.P. (the "Nexus Fund"), RA Capital Nexus III Fund, L.P. (the "Nexus Fund III"), and a separately managed account (the "Account"). The general partner of the Adviser is RA Capital Management GP, LLC (the "Adviser GP"), of which Dr. Peter Kolchinsky and Mr. Rajeev Shah are the managing members. The Adviser, the Adviser GP, the Fund, he Nexus Fund, the Nexus Fund III, Dr. Kolchinsky and Mr. Shah disclaim beneficial ownership of any of the reported securities, except to the extent of their pecuniary interest therein.

4. Held directly by the Nexus Fund.

5. Held directly by Nexus Fund III.

6. Held directly by the Account.

Remarks:

Joshua Resnick, a Partner of the Adviser, serves on the Issuer's board of directors.

	/s/ Peter Kolchinsky, Manager of RA Capital Management, L.P.	02/10/2025
	/s/ Peter Kolchinsky, Manager of RA Capital Healthcare Fund GP, LLC, the General Partner of RA Capital Healthcare Fund, L.P.	02/10/2025
	/s/ Peter Kolchinsky, Manager of RA Capital Nexus Fund GP, LLC, the General Partner of RA Capital Nexus Fund, L.P.	02/10/2025
	/s/ Peter Kolchinsky, Manager of RA Capital Nexus Fund III GP, LLC, the General Partner of RA Capital Nexus Fund III, L.P.	02/10/2025
	/s/ Peter Kolchinsky, individually	02/10/2025
	/s/ Rajeev Shah, individually	02/10/2025
	** Signature of Reporting Person	Date
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