Atrium Therapeutics launched after Novartis closed its acquisition of Avidity Biosciences, taking on Avidity’s cardiac RNA delivery programs and a public listing. The new company started operations with roughly $270 million in cash and two preclinical programs targeting PRKAG2 syndrome and PLN cardiomyopathy, diseases with no approved disease‑modifying therapies. Atrium’s leadership includes former Avidity executives and aims to leverage Avidity’s muscle‑targeted RNA delivery know‑how for cardiac indications.