Avidity Spinout Launches with $270 Million, Focus on Rare Cardiomyopathies

Rare Daily Staff

Atrium Therapeutics, a spinout from Avidity Biosciences, has launched as a newly independent, publicly traded company with approximately $270 million to develop precision RNA medicines for people with rare, genetic cardiomyopathies.

The debut follows Novartis’ $12 billion acquisition of Avidity, which is now an indirect, wholly owned subsidiary of the Swiss drugmaker. Atrium is inheriting an Avidity-designed targeted RNA delivery platform and will apply it to the heart rather than skeletal muscle. The platform enabled the first successful delivery of RNA to muscle and supported three rare neuromuscular programs into registrational development at Avidity.

Atrium’s technology combines the tissue selectivity of monoclonal antibodies and other targeted ligands with the precision of oligonucleotides to enable nonviral delivery of small interfering RNA directly to heart tissue. The approach builds on lessons from skeletal muscle delivery and is designed to address the long-standing problem of nonspecific distribution of RNA medicines. The goal is to selectively silence or modulate disease-driving genes in genetically defined cardiomyopathies and, over time, reset the standard of care.

Kathleen Gallagher, president and CEO of Atrium and a former Avidity executive, is leading the company with a team experienced in rare disease, RNA therapeutics, and cardiomyopathy drug development. Former Avidity CEO Sarah Boyce serves as board chair. The San Diego-based company trades on Nasdaq under the ticker RNA, taking over Avidity’s former listing with a new name and strategy. Boyce called precision cardiology “an area of immense opportunity.”

Atrium is advancing two wholly owned precision cardiology candidates: ATR-1072 for PRKAG2 syndrome and ATR-1086 for PLN cardiomyopathy. Both are described as severe, life-threatening, autosomal dominant, progressive cardiomyopathies with no approved therapies that address the underlying cause. The company is also running two undisclosed research-stage programs in rare cardiomyopathies.

IND-enabling studies and chemistry, manufacturing, and controls work are underway for ATR-1072, with Atrium planning to file an investigational new drug application in the second half of 2026. For ATR-1086, manufacturing work is planned to support the start of IND-enabling preclinical studies in 2026, with an IND filing targeted for 2027. Pending supportive phase 1 data, Atrium expects to move both programs into clinical development while it broadens its precision cardiology pipeline and iterates on its RNA delivery platform.

“Patients and families facing these genetically driven rare cardiomyopathies have few, if any, options that address the underlying cause,” Gallagher said. “Building on Avidity’s pioneering work in targeted RNA delivery, Atrium is positioned to advance precision medicines designed to directly target the biologic drivers of cardiac disease.”

Photo: Kathleen Gallagher, president and CEO of Atrium