Key Highlights

  • Nonclinical Results: A mouse-specific version of ATR-1072 reversed cardiac glycogen accumulation and improved additional disease features in a new PRKAG2 syndrome model.
  • New Animal Model: Atrium developed a mouse model that reproduces key features of PRKAG2 syndrome including cardiac hypertrophy and abnormal ECG findings.
  • Conference Presentation: Data are being presented at the Hypertrophic Cardiomyopathy Medical Society session at AHA Scientific Sessions 2026 on November 6.
  • Clinical Trial Progress: The ongoing Phase 1/2 Corventis trial is expected to produce initial proof-of-concept data in the second half of 2027.

Atrium Therapeutics, Inc.(NASDAQ:RNA), a biopharmaceutical company developing RNA therapeutics for cardiac diseases, will present new nonclinical data at the American Heart Association Scientific Sessions 2026 demonstrating that a surrogate molecule of its lead therapy ATR-1072 reversed key features of PRKAG2 syndrome in an animal model. The presentation takes place on November 6 during the Hypertrophic Cardiomyopathy Medical Society meeting held alongside the AHA conference in Chicago.

What PRKAG2 Syndrome Is and Why It Matters

PRKAG2 syndrome is a rare, hereditary condition caused by mutations in the PRKAG2 gene, which produces a regulatory subunit of an enzyme called AMPK. Mutations in this gene cause AMPK to remain abnormally active, leading to the accumulation of glycogen within heart muscle cells. Over time this produces a thickened heart, electrical conduction problems, and potentially dangerous arrhythmias. The disorder typically appears early in life and follows an autosomal dominant inheritance pattern, meaning a single copy of the mutated gene is sufficient to cause disease.

Estimates from the scientific literature suggest that at least 1,000 to 2,000 people in the US have PRKAG2 syndrome. Current management is limited to treating symptoms — pacemakers for conduction problems, medications for arrhythmias, and in some cases septal reduction procedures for obstructive hypertrophy. No approved therapy addresses the gene mutation driving the disease.

What the New Data Show

Atrium's research team developed a new mouse model that replicates multiple features of the human condition, including cardiac glycogen accumulation, cardiac hypertrophy, and ECG abnormalities. Mice were allowed to develop disease features over three weeks before receiving a single dose of mATR-1072, a mouse-adapted version of ATR-1072 designed to target PRKAG2 messenger RNA in the heart.

Following treatment, researchers observed Reversal of the cardiac glycogen accumulation. Cardiac hypertrophy and ECG abnormalities also showed improvement. Husam Younis, Chief Scientific Officer of Atrium Therapeutics, described the results as encouraging because the model reproduced the disease faithfully before treatment began, making the reversal of glycogen accumulation more meaningful as a scientific signal. The surrogate compound worked by reducing PRKAG2 mRNA in heart tissue, which reduced the abnormal AMPK activity driving glycogen storage.

Risks

Data from animal models of rare genetic diseases frequently Fail to translate directly to humans. The mouse model Atrium developed represents a significant research advance, but the differences in cardiac physiology between mice and humans mean that the magnitude of effect seen in this study may not predict what ATR-1072 will do in human patients. The Corventis Phase 1/2 trial is currently enrolling approximately 37 participants across two cohorts, a sample size that reflects the rarity of the disease but that limits the statistical power of early efficacy findings. A single dose in a surrogate molecule also does not replicate the dosing regimens that will be studied in the clinical trial.

What to Watch Next

Initial proof-of-concept data from the Corventis trial are expected in the second half of 2027. The primary endpoint of that study is safety, but secondary and exploratory endpoints include measures of PRKAG2 mRNA reduction in cardiac tissue, drug concentrations, and pharmacokinetic data. Any interim updates on enrollment progress or safety findings ahead of the anticipated 2027 data readout will provide earlier signals about how the clinical program is proceeding.

Sector Context

RNA therapeutics targeting the heart represent one of the more technically challenging frontiers in the broader field of genetic medicine. Delivering oligonucleotide therapies specifically to cardiac tissue — rather than having them distribute broadly to the liver, where most RNA therapies naturally concentrate — requires specialized delivery technology. Atrium's approach, which uses a delivery platform originally developed at Avidity Biosciences and designed to direct siRNA to specific tissues, addresses that challenge. How well cardiac selectivity holds up in humans, rather than animal models, is one of the central scientific questions the Corventis trial is designed to answer.