Ra Capital Management, L.P. - Nov 5, 2025 SCHEDULE 13D/A 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: 44.6M shares
Disclosed Ownership: 10.1M shares
Ownership: 22.6%
Form type: SCHEDULE 13D/A
Date filed: 11/7/2025, 04:59 PM
Date of event: Nov 5, 2025
Previous filing: Feb 18, 2025
SEC: View on sec.gov

Reporting Managers (5)

Name	Ownership	Shares Owned	shared voting power	Signature	Title	CIK
RA Capital Management, L.P.	22.6%	10.1M	10.1M	/s/ Peter Kolchinsky	By Peter Kolchinsky, Authorized Signatory	0001346824
Peter Kolchinsky	22.6%	10.1M	10.1M	/s/ Peter Kolchinsky	Peter Kolchinsky	0001384859
Rajeev Shah	22.6%	10.1M	10.1M	/s/ Rajeev Shah	Rajeev Shah	0001619841
RA Capital Healthcare Fund, L.P.	15.5%	6.91M	6.91M	/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%	2.24M	2.24M	/s/ Peter Kolchinsky	By RA Capital Nexus Fund III GP, LLC, its General Partner, By Peter Kolchinsky, Manager	0001883840