Atrium Therapeutics Doses First Patient In Its Phase 1/2 Corventis Clinical Trial Evaluating ATR 1072 For Potential Treatment Of PRKAG2 Syndrome; Expects Initial Proof-Of-Concept Data In H2 2027

Atrium Therapeutics, Inc. (NASDAQ:RNA) (the "Company"), a biopharmaceutical company advancing precision cardiology by developing RNA therapeutics targeted to the heart, today announced that the first patient has been dosed in the Phase 1/2 Corventis clinical trial evaluating ATR 1072, its lead investigational therapy for the potential treatment of PRKAG2 (Protein Kinase AMP-activated non-catalytic subunit Gamma 2) syndrome. The Company expects to report initial proof-of-concept data from Corventis in the second half of 2027.

PRKAG2 syndrome is a severe, life-threatening, rare autosomal dominant progressive cardiomyopathy with no approved therapies. It is caused by genetic mutations in PRKAG2 that lead to overactivity of AMP-activated protein kinase (AMPK), resulting in glycogen accumulation in heart muscle, which may lead to heart failure and sudden cardiac death. ATR 1072, based on the Company's targeted RNA delivery platform, is an antibody oligonucleotide conjugate (AOC) designed to silence mutant PRKAG2 messenger RNA (mRNA) to normalize AMPK overactivation and improve heart function.