RA CAPITAL MANAGEMENT, L.P. - 10 Feb 2025 SCHEDULE 13D Report for SIONNA THERAPEUTICS, INC. Common Stock, $0.001 par value per share (SION)

Filing Manager: RA CAPITAL MANAGEMENT, L.P.
Reporting Manager: RA Capital Management, L.P.
Security: SIONNA THERAPEUTICS, INC. Common Stock, $0.001 par value per share
Symbol: SION
Shares outstanding: 44,073,089 shares
Disclosed Ownership: 10,445,322 shares
Ownership: 24%
Form type: SCHEDULE 13D
Filing time: 18 Feb 2025, 16:25:23 UTC
Date of event: 10 Feb 2025
Next filing: 07 Nov 2025
SEC: View on sec.gov

Reporting Managers (5)

Name	Ownership	Shares Owned	shared voting power	Signature	Title	CIK
RA Capital Management, L.P.	24%	10,445,322	10,445,322	/s/ Peter Kolchinsky	By Peter Kolchinsky, Authorized Signatory	0001346824
Peter Kolchinsky	24%	10,445,322	10,445,322	/s/ Peter Kolchinsky	Peter Kolchinsky	0001384859
Rajeev Shah	24%	10,445,322	10,445,322	/s/ Rajeev Shah	Rajeev Shah	0001619841
RA Capital Healthcare Fund, L.P.	16%	6,923,365	6,923,365	/s/ Peter Kolchinsky	By RA Capital Healthcare Fund GP, LLC, its General Partner, By Peter Kolchinsky, Manager	0001315082
RA Capital Nexus Fund III, L.P.	5.3%	2,324,498	2,324,498	/s/ Peter Kolchinsky	By RA Capital Nexus Fund III GP, LLC, its General Partner, By Peter Kolchinsky, Manager	0001883840