Form 144 - Report of proposed sale of securities:
SEC Accession No. 0001628280-25-044112
Filing Date
2025-10-03
Accepted
2025-10-03 16:44:25
Documents
1

Document Format Files

Seq Description Document Type Size
1 primary_doc.html 144  
1 primary_doc.xml 144 6849
  Complete submission text file 0001628280-25-044112.txt   8518
Mailing Address 300 TECHNOLOGY SQUARE 8TH FLOOR CAMBRIDGE MA 02139
Business Address 300 TECHNOLOGY SQUARE 8TH FLOOR CAMBRIDGE MA 02139 857-201-2700
Atlas Venture Opportunity Fund II, L.P. (Reporting) CIK: 0001885327 (see all company filings)

EIN.: 872809161 | State of Incorp.: DE | Fiscal Year End: 1231

Mailing Address 21 HICKORY DRIVE, SUITE 500 WALTHAM MA 02451
Business Address 21 HICKORY DRIVE, SUITE 500 WALTHAM MA 02451 617-819-2020
Sionna Therapeutics, Inc. (Subject) CIK: 0002036042 (see all company filings)

EIN.: 000000000 | State of Incorp.: DE | Fiscal Year End: 1231
Type: 144 | Act: 33 | File No.: 001-42504 | Film No.: 251374603
SIC: 2834 Pharmaceutical Preparations
(CF Office: 03 Life Sciences)