Avidity Biosciences, Inc. Announces Major Corporate Transformation: Acquisition by Novartis AG and Spin-Off of Atrium Therapeutics

Avidity Biosciences, Inc. is undergoing a significant corporate transformation. Its stockholders have approved a definitive agreement for the company's acquisition by Novartis AG, a move that also includes the spin-off of a new, independent entity, Atrium Therapeutics, Inc. (formerly Bryce Therapeutics, Inc.), which will manage specific non-core assets.

The Transaction Details

On February 26, 2026, Avidity Biosciences stockholders overwhelmingly approved the merger agreement with Novartis AG, originally signed on October 25, 2025. Under the terms of the agreement, Novartis AG will acquire all outstanding shares of Avidity Biosciences. Shareholders will receive a total consideration of $50.00 per share, paid as $30.00 in cash and 0.5 shares of Novartis AG common stock for each Avidity share they hold. The acquisition values the company at approximately $6.5 billion.

Alongside the acquisition, Avidity Biosciences will spin off Atrium Therapeutics, Inc. Avidity shareholders will receive one share of Atrium Therapeutics, Inc. common stock for every five Avidity shares they own, distributed as a pro rata dividend just before the merger closes. Atrium Therapeutics will trade as an independent public company on the Nasdaq Stock Market under a new ticker symbol following the spin-off.

Strategic Rationale

This significant move is driven by clear strategic objectives for all parties involved:

For Novartis AG: This acquisition significantly strengthens Novartis's gene therapy and rare disease pipeline by integrating Avidity's proprietary Antibody Oligonucleotide Conjugate (AOC) platform. Novartis plans to leverage Avidity's lead candidate, AOC 1001 for Myotonic Dystrophy Type 1 (DM1), and other promising programs to speed up development and broaden its therapeutic reach in neuromuscular and other rare genetic disorders.

For Avidity Biosciences: The Board of Directors unanimously recommended the deal, highlighting the substantial premium offered to shareholders and the increased resources Novartis can provide to advance Avidity's innovative drug candidates. This partnership should accelerate critical therapies' path to market, benefiting patients globally.

For Atrium Therapeutics, Inc.: The spin-off enables independent development of Avidity's earlier-stage research programs and non-core assets, especially those not central to Novartis's acquisition strategy. Atrium Therapeutics will initially focus on novel therapies for rare neurological disorders. It will use a dedicated management team and an initial cash balance of approximately $200 million to fund its operations and pipeline development.

Timeline and Next Steps

The transaction is expected to close in Q2 2026, pending standard closing conditions, such as regulatory approvals (e.g., antitrust clearances). Once closed, Avidity Biosciences' common stock will be delisted from the Nasdaq Stock Market. Avidity shareholders will then receive their cash and Novartis shares, along with their Atrium Therapeutics shares.

Impact on Stakeholders

This corporate transformation will have distinct effects on various stakeholders:

• Avidity Shareholders: Will receive a significant financial return through cash and Novartis shares, plus a new investment opportunity in Atrium Therapeutics.
• Avidity Employees: Will transition to Novartis or Atrium Therapeutics, gaining access to a global pharmaceutical leader's resources or contributing to a focused, agile biotech startup.
• Patients: Novartis's extensive resources are expected to accelerate the development of Avidity's promising drugs, such as AOC 1001 for DM1, potentially bringing life-changing treatments to market faster.

Key Investor Considerations

For investors, several critical factors warrant attention:

• Specific Deal Terms: Shareholders need to understand the exact per-share consideration ($30.00 cash, 0.5 Novartis AG shares, and 1 Atrium Therapeutics share for every 5 Avidity shares).
• Regulatory Approvals: Although shareholders have approved the deal, the merger still requires regulatory clearances, which could lead to delays or, rarely, termination.
• Atrium Therapeutics: Investors should evaluate Atrium as a new, independent company with its own risk profile, management, and strategic direction. Its initial trading performance and long-term viability will depend on its pipeline and financial execution.
• Delisting: Avidity Biosciences stock will stop trading independently once the merger completes.
• Action Required: Shareholders should consult their brokers about converting their Avidity shares and receiving Atrium Therapeutics shares.

Investors should watch for official announcements regarding the definitive closing date and further details about Atrium Therapeutics' public trading debut.