Atrium Therapeutics launched as a spinout from Avidity Biosciences after Novartis closed its acquisition, taking on cardiovascular RNA programs and a $270 million cash position. The new company will advance two preclinical candidates targeting PRKAG2 syndrome and PLN cardiomyopathy and retain certain Avidity assets that were not included in the Novartis deal. Atrium is led by former Avidity executives including CEO Kathleen Gallagher and will pursue muscle‑targeted RNA delivery approaches that earlier attracted interest from big pharmas. Management says programs are preclinical with plans to enter the clinic within the coming years while leveraging prior platform work on tissue delivery.