SEC Form 4 · accession 0001231919-26-001201
Sionna Therapeutics, Inc. · SION
Statement of changes in beneficial ownership, as filed. Original on EDGAR ↗
Reporting owners
RA Capital Healthcare Fund LP
Director
RA CAPITAL MANAGEMENT, L.P.
Director · 10% Owner
Peter Kolchinsky
Director · 10% Owner
Rajeev M. Shah
Director · 10% Owner
RA Capital Nexus Fund, L.P.
Director
RA Capital Nexus Fund III, L.P.
Director
Period of report
Sep 17, 2026
Accepted (ET)
Sep 21, 2026 · 6:56 pm EDT
Rule 10b5-1 plan
box not checked
Issuer CIK
0002036042
Table I — non-derivative securities
| Security | Date | Code | Shares | Price | A/D | Owned after | D/I | Nature of ownership |
|---|---|---|---|---|---|---|---|---|
| Common StockF1,F2 | Sep 17, 2026 | S | 3,415,011 | $6.32 | D | 3,482,612 | I | See footnotes |
| Common StockF3,F1,F2 | Sep 17, 2026 | S | 33,800 | $7.46 | D | 3,448,812 | I | See footnotes |
| Common StockF1,F4 | holding | — | — | — | 650,307 | I | See footnotes | |
| Common StockF1,F5 | holding | — | — | — | 2,198,082 | I | See footnotes | |
| Common StockF1,F6 | holding | — | — | — | 159,033 | I | See footnotes |
Table II — derivative securities
No Table II lines on this filing.
Explanation of responses
- F1RA Capital Management, L.P. (the "Adviser") is the investment manager for RA Capital Healthcare Fund, L.P. (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, the 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.
- F2Held directly by the Fund.
- F3The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $7.30 to $7.68 inclusive. The Reporting Persons undertake to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote.
- F4Held directly by the Nexus Fund.
- F5Held directly by the Nexus Fund III.
- F6Held directly by the Account.
Remarks
Dr. Joshua Resnick, a Partner of the Adviser, serves on the Issuer's board of directors.