Avidity details spin-off of precision cardiology assets as Novartis deal progresses

Avidity Biosciences has designated February 12, 2026, as the expected record date for the planned spin-off of Atrium Therapeutics, Inc., in connection with Avidity’s proposed acquisition by Novartis AG. Under the disclosed terms, stockholders of record will receive one share of Atrium for every ten shares of Avidity common stock. Atrium will hold Avidity’s early-stage precision cardiology programs. Avidity’s Antibody Oligonucleotide Conjugate platform and neuromuscular programs are not described as being part of Atrium Therapeutics.

The transaction structure separates specific early-stage assets from the rest of Avidity’s portfolio prior to the proposed acquisition. For Avidity shareholders, the spin-off results in direct ownership of a standalone entity holding the cardiology programs, alongside continued exposure to the remaining Avidity business pending completion of the merger. The company has stated that the expected record date may change depending on the closing date of the transaction.

The restructuring follows prior Onyx coverage from November 2024. At that time, the company had raised more than $1.1 billion and outlined plans to independently commercialize its rare muscle disease programs on a global basis. Management highlighted its AOC technology, which uses antibodies to deliver siRNA therapeutics to muscle tissue, as central to its approach in indications such as myotonic dystrophy type 1 and Duchenne muscular dystrophy. Avidity also pointed to multiple large pharmaceutical collaborations, including a cardiology partnership with Bristol Myers Squibb and an immunology collaboration with Eli Lilly, while maintaining that internal commercialization of skeletal muscle programs was the priority.

Completion of the proposed acquisition remains subject to Avidity stockholder approval and other customary closing conditions, as detailed in the definitive proxy statement filed on January 30, 2026.

You can read our previous interviews with Avidity Bioscience's CEO, Sarah Boyce, from November 2024.