Winslow Brendan R. 4

What Happened
Brendan R. Winslow, Chief Financial Officer of Atrium Therapeutics, received compensation awards on April 20, 2026: 30,000 restricted stock units (RSUs) and a 60,000-share option grant (reported as a derivative acquisition). Both awards were granted at $0.00 (i.e., no cash paid). These are grants/awards (not open‑market purchases or sales).

Key Details

• Transaction date: April 20, 2026; Form 4 filed April 22, 2026 (timely, within the typical two‑business‑day reporting window). Accession: 0001193125-26-170960.
• RSUs: 30,000 RSUs granted at $0.00. (Footnote F1)
• Options/derivative: 60,000 shares granted as a derivative security at $0.00. (Footnote F2)
• Shares owned after the transaction: not specified in the filing.
• No 10b5-1 plan, tax‑withholding, or sale noted in this filing.
• Footnotes: F1 explains each RSU converts to one share upon vesting; 25% vests March 20, 2027, then three equal annual installments thereafter, subject to continued service. F2 explains option vesting: 25% vests March 20, 2027, then the remainder vests in 36 substantially equal monthly installments, subject to continued service.

Context RSUs are a contingent right to receive company shares once vested; stock options give the right to buy shares in the future if the holder exercises. Both awards are common forms of executive compensation intended for retention and alignment with shareholders; they do not involve an immediate cash outlay or sale of shares and should not be interpreted alone as a buy/sell signal.