Steven George Hughes, Chief Medical Officer of Atrium Therapeutics, Inc., filed a statement of changes in beneficial ownership on September 22, 2026, reporting a disposition of common stock tied to the vesting of restricted stock units on September 18, 2026.

Key Highlights

  • Reporting person: Steven George Hughes, Chief Medical Officer of Atrium Therapeutics, Inc.
  • Transaction date: September 18, 2026, with the filing submitted September 22, 2026.
  • Shares disposed: 21,459 shares of common stock withheld at a price of $8.95 per share.
  • Purpose of disposition: Shares were withheld by the issuer to satisfy tax withholding obligations in connection with the vesting of restricted stock units, according to the filing.
  • Remaining ownership: Following the transaction, Hughes directly holds 51,638 shares of common stock.

Atrium Therapeutics CMO Reports RSU Vesting Tax Withholding Transaction

According to the filing, Steven George Hughes, who serves as Chief Medical Officer at Atrium Therapeutics, Inc. (NASDAQ:RNA), a biopharmaceutical company based in San Diego, California, reported a single non-derivative securities transaction coded "F" in Table I. The transaction code "F" designates shares withheld by the issuer for payment of an exercise price or for tax withholding in connection with an equity award, as defined under the applicable SEC instructions.

The filing discloses that 21,459 shares of Atrium Therapeutics common stock were disposed of on September 18, 2026, at a per-share price of $8.95. As the filing's footnote states, these shares represent amounts "withheld by the Issuer to satisfy tax withholding obligations in connection with the vesting of restricted stock units." Following this disposition, Hughes directly beneficially owns 51,638 shares of common stock, with no indirect holdings reported and no derivative securities activity noted in Table II.

The filing was submitted by Brendan Winslow as attorney-in-fact on behalf of Hughes and was signed on September 22, 2026. The filing indicates it was made by one reporting person acting individually, with no joint or group filing involved. No amendment date was listed, indicating this is an original filing.

What Was Disclosed

The filing reported that Atrium Therapeutics' Chief Medical Officer had 21,459 shares of common stock withheld at $8.95 per share on September 18, 2026, to cover tax obligations tied to restricted stock unit vesting, leaving a direct beneficial ownership position of 51,638 shares.