Atrium Therapeutics, Inc SEC Filings

Avidity Biosciences (RNA) filed a Form 144 reporting a proposed sale of 50,000 common shares to be executed through Morgan Stanley Smith Barney on 09/05/2025, with an aggregate market value of $2,423,500 based on the filing. The shares were acquired on 09/05/2025 by exercise of stock options and paid in cash. The filer also reported prior 10b5-1 sales of 25,000 shares on 08/28/2025 generating gross proceeds of $1,234,700. The filing includes the required representation that the seller is not aware of undisclosed material adverse information and references reliance on Rule 10b5-1 trading instructions where applicable.

Form 144 filed for Avidity Biosciences (RNA) reports a proposed sale of common stock totaling 95,052 shares with an aggregate market value of $4,752,600, to be sold through UBS Financial Services on Nasdaq on 09/05/2025. The filing lists the issuer's total shares outstanding as 128,653,337, so the proposed sale represents a small fraction of the company’s outstanding stock.

The filer shows prior acquisitions including a stock option exercise on 09/05/2025 for 14,500 shares paid in cash and long-held shares acquired in 2018 and 2012 totaling 80,552 shares. The filing also discloses multiple related-party sales on 08/06/2025 totaling 97,054 shares with combined gross proceeds reported.

Avidity Biosciences (RNA) filing a Form 144 shows a proposed sale of 19,688 common shares with an aggregate market value of $929,864.24 to be executed on 09/03/2025 through Morgan Stanley Smith Barney on NASDAQ. The filing indicates these shares were acquired the same day by exercise of stock options and paid in cash. The notice also discloses prior Rule 10b5-1 sales by the same person on 08/06/2025 totaling 130,807 shares for $5,763,699.79. Several standard filer and issuer identification fields in the form are blank or not provided in the text.

Kathleen P. Gallagher, Chief Program Officer at Avidity Biosciences, Inc. (RNA), reported a sell-to-cover transaction tied to RSU vesting. On September 2, 2025 she sold 188 shares of Avidity common stock at $47.42 per share to satisfy tax withholding from RSUs that vested on August 30, 2025. The filing states the sale was executed under the issuer's sell-to-cover election and pursuant to an instruction letter intended to meet the affirmative defense conditions of Rule 10b5-1. After the transaction she beneficially owned 50,204 shares (direct).

Sarah Boyce, President and CEO and a director of Avidity Biosciences, Inc. (RNA), exercised options and sold shares on 08/28/2025 under a previously adopted Rule 10b5-1 trading plan. The reporting person exercised a stock option to acquire 25,000 shares at an exercise price of $1.24 and contemporaneously sold 25,000 shares at a weighted-average sales price of $49.388 per share (sales ranged $49.23–$49.52). The filings show direct beneficial ownership of common stock decreased from 330,871 shares before the sale to 305,871 shares after the sale. The option award exercised was fully vested and exercisable as of the transaction date, and Table II reports 25,000 underlying shares from the exercised option and a total of 1,072,015 derivative securities beneficially owned following the transaction as reported on the form. The trades were effected pursuant to a 10b5-1 plan adopted August 15, 2024.

Avidity Biosciences (RNA) filed a Form 144 reporting the proposed sale of 25,000 shares of common stock through Morgan Stanley Smith Barney LLC on NASDAQ with an aggregate market value of $1,195,500. The filing shows the shares were acquired and paid for on 08/28/2025 via exercise of stock options from the issuer, and the filer reports no securities sold in the past three months. The notice includes the filer’s representation that they are not aware of undisclosed material adverse information and contains the standard signature and certification language.

Steven George, Chief Medical Officer of Avidity Biosciences (RNA), exercised stock options and sold shares under a preexisting Rule 10b5-1 plan. On 08/22/2025 he exercised options to acquire 2,208 shares at an exercise price of $10.16 per share and simultaneously sold 2,208 shares in multiple transactions at a weighted-average sale price of $46.4047 per share, with individual sale prices ranging from $44.64 to $47.03. After these transactions he beneficially owned 41,075 shares before the sale and 38,867 shares following the sale. The option exercised was granted 01/20/2024, vests monthly in equal installments of 2,208 shares and becomes fully vested on 01/20/2028. The reporting person adopted the 10b5-1 plan on 06/12/2024.

Avidity Biosciences insider activity: Teresa McCarthy, Chief Human Resources Officer, effected option exercise and share sales under a Rule 10b5-1 plan on 08/15/2025. She exercised a stock option with a $22.34 exercise price for 10,000 shares and immediately sold 10,000 common shares in multiple transactions at a weighted-average price of $46.5632, with trade prices ranging $45.36 to $47.50. After these transactions the reporting person beneficially owned 97,130 shares of common stock and held options covering 100,000 shares. The option shares were fully vested as of the exercise date.

Avidity Biosciences, Inc. (RNA) reported a proposed sale under Rule 144 of 45,000 common shares through Morgan Stanley Smith Barney LLC with an aggregate market value of $2,073,150.00. The filing indicates the shares were acquired and are to be sold on 08/15/2025 following the exercise of stock options granted by the issuer, with payment made in cash. The company has 128,653,337 shares outstanding, and the filer reports no other sales in the past three months. The filer certifies they are not aware of undisclosed material adverse information and follows the Rule 144 attestation requirements.