Atlas Venture Fund XI, L.P. - 16 Oct 2025 SCHEDULE 13D/A Report for SIONNA THERAPEUTICS, INC. Common Stock (SION)

Filing Manager
Atlas Venture Fund XI, L.P.
Reporting Manager
Atlas Venture Fund XI, L.P.
Security
SIONNA THERAPEUTICS, INC. Common Stock
Symbol
SION
Shares outstanding
44.1M shares
Disclosed Ownership
2.38M shares
Ownership
5.4%
Form type
SCHEDULE 13D/A
Filing time
20 Oct 2025, 21:40:43 UTC
Date of event
16 Oct 2025
Previous filing
18 Feb 2025
SEC
View on sec.gov

Reporting Managers (6)

Name Ownership Shares Owned sole voting power shared voting power Signature Title CIK
Atlas Venture Fund XI, L.P. 5.4% 2.38M 0 2.38M /s/ Ommer Chohan Atlas Venture Associates XI, L.P., its GP, By Atlas Venture Associates XI, LLC, its GP, By: Ommer Chohan, CFO 0001708269
Atlas Venture Associates XI, L.P. 5.4% 2.38M 0 2.38M /s/ Ommer Chohan Atlas Venture Associates XI, LLC, its GP, By: Ommer Chohan, CFO 0001780068
Atlas Venture Associates XI, LLC 5.4% 2.38M 0 2.38M /s/ Ommer Chohan Ommer Chohan, CFO 0001780067
Atlas Venture Opportunity Fund II, L.P. 1.6% 702K 0 702K /s/ Ommer Chohan Atlas Venture Associates Opportunity II, L.P., its GP, By: Atlas Venture Associates Opportunity II, LLC, its GP, By: Ommer Chohan, CFO 0001885327
Atlas Venture Associates Opportunity II, LP 1.6% 702K 0 702K /s/ Ommer Chohan Atlas Venture Associates Opportunity II, LLC, its GP, By: Ommer Chohan, CFO 0001935814
Atlas Venture Associates Opportunity II, LLC 1.6% 702K 0 702K /s/ Ommer Chohan By: Ommer Chohan, CFO 0001935810