ORBIMED ADVISORS LLC 4
4 · Sionna Therapeutics, Inc. · Filed May 11, 2026
Research Summary
AI-generated summary of this filing
Sionna (SION) Director OrbiMed Advisors Sells Shares
What Happened OrbiMed Advisors LLC, reported as a director-related reporting person for Sionna Therapeutics (SION), sold a total of 292,952 shares in three open-market transactions. The sales were: 48,546 shares on 2026-05-07 at $44.61 ($2,165,637); 59,767 shares on 2026-05-08 at $44.58 ($2,664,413); and 184,639 shares on 2026-05-11 at $46.22 ($8,534,015). Combined proceeds were about $13.36 million. These were disposals (sales), not purchases.
Key Details
- Transaction dates & prices:
- 2026-05-07: 48,546 shares @ $44.61 — $2,165,637
- 2026-05-08: 59,767 shares @ $44.58 — $2,664,413
- 2026-05-11: 184,639 shares @ $46.22 — $8,534,015
- Total shares sold: 292,952; total proceeds: ~$13.36M.
- Filing: Form 4 filed 2026-05-11 (reporting transactions through 2026-05-11); the report shows no late-filing flag.
- Post-transaction shares owned: not specified in the provided filing details.
- Notable footnotes:
- F1: The sales were made pursuant to a pre-arranged 10b5-1 trading plan.
- F2–F3: The shares are held of record by OrbiMed Private Investments VIII, LP (OPI VIII); OrbiMed Advisors and its general-partner entities describe voting/investment relationships and disclaim beneficial ownership except for any pecuniary interest. The Form 4 was jointly filed by OrbiMed Advisors and the GP entity.
Context These sales were executed by an institutional investor and reported by its advisory/GP entities — not an individual executive. The use of a 10b5-1 plan indicates the trades were pre-arranged, which commonly reduces the indication that they were timed based on nonpublic information. For retail investors, purchases by insiders can be more informative than routine institutional sales; this filing documents sizable disposals by an OrbiMed-managed vehicle rather than a CEO/CFO buy.
Insider Transaction Report
- Sale
Common Stock
[F1][F2][F3]2026-05-07$44.61/sh−48,546$2,165,637→ 2,916,228 total(indirect: See footnotes() - Sale
Common Stock
[F1][F2][F3]2026-05-08$44.58/sh−59,767$2,664,413→ 2,856,461 total(indirect: See footnotes() - Sale
Common Stock
[F1][F2][F3]2026-05-11$46.22/sh−184,639$8,534,015→ 2,671,822 total(indirect: See footnotes()
Footnotes (3)
- [F1]These securities were sold pursuant to a 10b5-1 plan.
- [F2]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.
- [F3]This report on Form 4 is jointly filed by OrbiMed Advisors and GP VIII. Each of the Reporting Persons 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. The Reporting Persons have designated a representative, Peter A. Thompson, a member of OrbiMed Advisors, to serve on the Issuer's board of directors. 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.