Welcome to our dedicated page for Atrium Therapeutics SEC filings (Ticker: RNA), a comprehensive resource for investors and traders seeking official regulatory documents including 10-K annual reports, 10-Q quarterly earnings, 8-K material events, and insider trading forms.
Atrium Therapeutics filings document the corporate transition that created the current RNA issuer and the related Avidity Biosciences merger, separation and listing records. The filing set includes 8-K material-event reports, shareholder voting disclosures, separation and merger agreement records, capital-structure information and a Form 25 covering removal of Avidity common stock from Nasdaq listing and registration.
Regulatory disclosures tied to the symbol also cover governance matters, operating and financial results, clinical or regulatory updates and security-structure information. As an independent biopharmaceutical company, Atrium's filings center on its RNA therapeutics platform, precision cardiology pipeline, collaboration economics, equity compensation and public-company reporting obligations.
Avidity Biosciences, Inc. has set an expected record date of February 12, 2026 for a planned pro rata distribution of all issued and outstanding shares of common stock of Atrium Therapeutics, Inc. to holders of Avidity common stock as of that date.
This planned spin-off of Atrium Therapeutics, referred to as SpinCo, is tied to the previously announced proposed acquisition of Avidity by Novartis AG and the separation of Avidity’s early-stage precision cardiology programs into SpinCo. The filing emphasizes that completion and timing of these transactions depend on customary closing conditions, regulatory approvals, and Avidity stockholder approval, and highlights numerous risks that could cause actual outcomes to differ from current expectations.
Avidity Biosciences has agreed to be acquired by Novartis for $72.00 in cash per share, with stockholders also receiving value from a spin-off or sale of its early-stage precision cardiology programs. These assets will be moved into Atrium Therapeutics (SpinCo) and either distributed as stock at one SpinCo share for every ten Avidity shares or sold to a third party with cash proceeds distributed pro rata. The merger and spin-off require approval of a majority of outstanding Avidity shares at a virtual special meeting on February 23, 2026. Avidity’s board unanimously recommends voting in favor, and stockholders who properly exercise Delaware appraisal rights may seek a court-determined cash value instead of the $72.00 merger consideration while still receiving spin-off value.
Avidity Biosciences, Inc. Chief Medical Officer Steven George Hughes reported automatic sales of common stock to cover taxes on vested RSUs. On January 21, 2026, he sold 2,017 shares of common stock at $72.45 per share, then a further 2,878 shares at the same price. After these transactions, he beneficially owned 31,599 shares of Avidity common stock directly.
According to the footnote, these transactions represent shares sold to satisfy tax withholding obligations arising from RSUs that vested on January 20, 2026. The sales were mandated under the company’s equity incentive plans as a “sell-to-cover” arrangement and are described as non-discretionary trades. The reporting person executed an instruction letter for automatic sale of these sell-to-cover shares intended to meet the affirmative defense conditions of Rule 10b5-1.
Avidity Biosciences President and CEO Sarah Boyce reported automatic sales of common stock tied to tax withholding on vested equity awards. On January 21, 2026, she sold 6,394 shares of common stock at $72.45 per share and an additional 7,993 shares at $72.45 per share.
According to the filing, these transactions represent shares sold to cover tax obligations arising from the vesting of RSUs on January 20, 2026 under a mandatory "sell-to-cover" arrangement elected by the company. The filing states these sales do not represent discretionary trades and are executed under an automatic instruction letter intended to satisfy Rule 10b5-1 affirmative defense conditions. Following the reported transactions, Boyce beneficially owned 269,007 shares of Avidity Biosciences common stock directly.
Avidity Biosciences, Inc. Chief Scientific Officer W. Michael Flanagan reported automatic sales of common stock to cover taxes tied to restricted stock unit (RSU) vesting. On January 21, 2026, he sold 3,976 shares and 2,558 shares of Avidity common stock at $72.45 per share in separate transactions, totaling 6,534 shares.
These sales were required to satisfy tax withholding obligations under the company’s equity incentive plans through a mandated “sell-to-cover” arrangement and are described as not being discretionary trades. After the transactions, Flanagan directly owned 85,093 shares of Avidity common stock. The instruction letter for these automatic sales is intended to meet the affirmative defense conditions of Rule 10b5-1.
Avidity Biosciences, Inc. Chief Financial Officer Michael F. MacLean reported automatic sales of common stock to cover taxes on vested RSUs. On January 21, 2026, he sold 1,807 shares of Avidity common stock at $72.45 per share, followed by a sale of 2,735 shares at the same price. After these transactions, he directly owned 59,290 shares of common stock.
According to the footnote, these transactions represent shares sold to satisfy tax withholding obligations arising from RSUs that vested on January 20, 2026. The sales were mandated under the company’s equity incentive plans as “sell-to-cover” transactions, executed under an instruction letter designed to meet the affirmative defense conditions of Rule 10b5-1, and are described as non-discretionary trades by the CFO.
Avidity Biosciences director Arthur A. Levin reported an automatic sale of common stock tied to RSU vesting. On January 21, 2026, 1,758 shares of Avidity Biosciences common stock were sold at $72.45 per share in a transaction coded "S." According to the footnote, this was a mandated "sell-to-cover" sale to satisfy tax withholding obligations from restricted stock units that vested on January 20, 2026, under the company’s equity incentive plans, and it was not a discretionary trade. After this sale, Levin directly held 16,562 common shares, and additional common shares were held indirectly through a family trust and a charitable remainder trust. The filing notes that instructions for these automatic sell-to-cover transactions were established under Rule 10b5-1.
Avidity Biosciences’ Chief Human Resources Officer Teresa McCarthy reported automatic share sales tied to RSU vesting. On January 21, 2026, she sold 1,476 shares of Avidity Biosciences common stock at $72.45 per share, leaving her with 115,391 shares directly owned. A second sale the same day covered 1,453 shares at $72.45 per share, after which she directly held 113,938 shares.
According to the footnote, these transactions were required to cover tax withholding obligations from restricted stock units that vested on January 20, 2026. The issuer mandates a “sell-to-cover” method under its equity incentive plans, so these sales were not discretionary trades by McCarthy. She also executed an instruction letter intended to satisfy the affirmative defense conditions of Rule 10b5-1, meaning the sales followed a pre-established automatic trading instruction.
Novartis AG has filed proxy-related materials describing its proposed acquisition of Avidity Biosciences, Inc. through a merger in which Novartis would indirectly acquire all outstanding Avidity shares. The transaction is linked to a planned spin-off or sale of Atrium Therapeutics, Inc. (“SpinCo”) from Avidity.
Avidity will prepare and deliver a definitive proxy statement and proxy card to its stockholders in advance of a special meeting to vote on the transactions. The materials emphasize that stockholders should read the definitive proxy statement and related SEC filings because they will contain important information about the deals and the parties involved.
The communication explains that Novartis, Avidity, SpinCo and certain of their directors, officers and employees may be considered participants in the proxy solicitation, and refers investors to existing SEC filings for details on their interests. It also includes extensive forward-looking statements language, noting that completion of the transactions is subject to customary closing conditions, including regulatory approvals and approval by Avidity stockholders, and highlighting risks such as potential delays, higher-than-expected costs, competing offers, business disruption and possible stockholder litigation.
Novartis AG has filed proxy-related materials describing its proposed acquisition of Avidity Biosciences, Inc. through a merger in which Novartis would indirectly acquire all outstanding Avidity shares. The transaction is linked to a planned spin-off or sale of Atrium Therapeutics, Inc. (“SpinCo”) from Avidity.
Avidity will prepare and deliver a definitive proxy statement and proxy card to its stockholders in advance of a special meeting to vote on the transactions. The materials emphasize that stockholders should read the definitive proxy statement and related SEC filings because they will contain important information about the deals and the parties involved.
The communication explains that Novartis, Avidity, SpinCo and certain of their directors, officers and employees may be considered participants in the proxy solicitation, and refers investors to existing SEC filings for details on their interests. It also includes extensive forward-looking statements language, noting that completion of the transactions is subject to customary closing conditions, including regulatory approvals and approval by Avidity stockholders, and highlighting risks such as potential delays, higher-than-expected costs, competing offers, business disruption and possible stockholder litigation.
Novartis AG has filed proxy materials related to its proposed acquisition of Avidity Biosciences, Inc., which will be paired with a spin-off or sale of Atrium Therapeutics, Inc. (SpinCo). An internal message to Avidity employees explains that, following closing of the transaction, Stephen Moran, currently a Novartis executive, is expected to become Managing Director of Avidity Biosciences and will work with Avidity’s leadership to preserve its culture, AOC platform and pipeline.
The communication emphasizes that until closing, Novartis and Avidity remain separate companies, with no changes to existing structures or reporting lines. It also notes that Avidity will send a definitive proxy statement and proxy card to its stockholders ahead of a special meeting to vote on the transactions, and urges investors to read that document when available. Extensive forward-looking statement language highlights that completion of the deal, the SpinCo separation and expected benefits are subject to risks, including regulatory and stockholder approvals and potential business disruptions.
Novartis AG has filed proxy materials related to its proposed acquisition of Avidity Biosciences, Inc., which will be paired with a spin-off or sale of Atrium Therapeutics, Inc. (SpinCo). An internal message to Avidity employees explains that, following closing of the transaction, Stephen Moran, currently a Novartis executive, is expected to become Managing Director of Avidity Biosciences and will work with Avidity’s leadership to preserve its culture, AOC platform and pipeline.
The communication emphasizes that until closing, Novartis and Avidity remain separate companies, with no changes to existing structures or reporting lines. It also notes that Avidity will send a definitive proxy statement and proxy card to its stockholders ahead of a special meeting to vote on the transactions, and urges investors to read that document when available. Extensive forward-looking statement language highlights that completion of the deal, the SpinCo separation and expected benefits are subject to risks, including regulatory and stockholder approvals and potential business disruptions.