Atrium Therapeutics launched as a spinout from assets left out of Novartis’s $12 billion acquisition of Avidity Biosciences, taking on preclinical RNA programs for rare cardiomyopathies and roughly $270 million in cash. The new company is led by former Avidity executives, including Kathleen Gallagher as CEO, and will focus on PRKAG2 syndrome, PLN cardiomyopathy and additional undisclosed targets. Atrium assumes Avidity’s public listing and delivery technology aimed at targeting RNA therapeutics to heart muscle—an area where traditional nucleic acid medicines struggle to reach. The firm said initial programs are preclinical with plans to enter the clinic within two years. Investors and industry watchers see the spinout as a way to preserve program value outside the core Novartis neuromuscular buy, while enabling focused development of cardio-directed RNA delivery approaches.