Thompson Peter A. 4
4 · Sionna Therapeutics, Inc. · Filed Feb 4, 2026
Research Summary
AI-generated summary of this filing
Sionna Therapeutics (SION) Director Peter A. Thompson Sells Shares
What Happened
- Peter A. Thompson, a director of Sionna Therapeutics, sold a total of 30,953 shares in open-market/private-sale transactions. On 2026-02-02 he disposed of 1,890 shares at $44.57 each for $84,237; on 2026-02-03 he disposed of 29,063 shares at $44.58 each for $1,295,629. Total proceeds were $1,379,866 (approx. $1.38M). These were sales (S), not purchases.
Key Details
- Transaction dates and prices: 2026-02-02 — 1,890 sh @ $44.57; 2026-02-03 — 29,063 sh @ $44.58.
- Total shares sold: 30,953; total proceeds: $1,379,866 (~$1.38M).
- Shares owned after transaction: Not specified in the provided summary of the Form 4.
- Filing timeliness: Report filed 2026-02-04; covers transactions on Feb 2–3, 2026 and appears to be filed within the standard two-business-day Form 4 window.
- Footnotes of note:
- The shares are held of record by OrbiMed Private Investments VIII, LP (OPI VIII). OrbiMed Advisors LLC and OrbiMed Capital GP VIII LLC are related entities; Thompson is a member of OrbiMed Advisors (F1).
- The filing includes disclaimers that the Reporting Person, OrbiMed Advisors, and GP VIII disclaim beneficial ownership except to the extent of any pecuniary interest (F2).
Context
- These were straight sales of existing shares (S codes), not option exercises, awards, purchases, or gifts. Sales can be routine (portfolio rebalancing, fund-level liquidity, tax planning, etc.) and do not, by themselves, prove a change in insider sentiment.
- Because the securities are held of record by an OrbiMed investment vehicle and Thompson is linked through OrbiMed Advisors, this reflects transactions associated with an investment fund structure rather than necessarily a direct personal transfer of individually held shares.
Insider Transaction Report
Form 4
Thompson Peter A.
Director
Transactions
- Sale
Common Stock
[F1][F2]2026-02-02$44.57/sh−1,890$84,237→ 3,559,765 total(indirect: See footnotes) - Sale
Common Stock
[F1][F2]2026-02-03$44.58/sh−29,063$1,295,629→ 3,530,702 total(indirect: See footnotes)
Footnotes (2)
- [F1]These securities are held of record by OrbiMed Private Investments VIII, LP ("OPI VIII"). OrbiMed Capital GP VIII LLC ("GP VIII") is the general partner of OPI VIII and OrbiMed Advisors LLC ("OrbiMed Advisors") is the managing member of GP VIII. By virtue of such relationships, GP VIII and OrbiMed Advisors may be deemed to have voting and investment power with respect to the shares held by OPI VIII and as a result may be deemed to have beneficial ownership of such shares. OrbiMed Advisors exercises investment and voting power through a management committee comprised of Carl L. Gordon, Sven H. Borho, and W. Carter Neild, each of whom disclaims beneficial ownership of the shares held by OPI VIII. The Reporting Person is a member of OrbiMed Advisors.
- [F2]Each of the Reporting Person, OrbiMed Advisors, and GP VIII disclaims beneficial ownership of the securities reported herein for purposes of Rule 16a-1(a) under the Securities Exchange Act of 1934, as amended (the "Exchange Act"), except to the extent of its pecuniary interest therein, if any. This report shall not be deemed an admission that any such entity or person is a beneficial owner of such securities for purposes of Section 16 of the Exchange Act, or for any other purpose.
Signature
/s/ Peter A. Thompson|2026-02-04