Atrium Therapeutics Reports Second Quarter 2026 Financial Results (Form 8-K)

Atrium Therapeutics Reports Second Quarter 2026 Financial Results

- IND clearance for ATR 1072 and launch of Corventis Phase 1/2 trial in

PRKAG2 syndrome -

- Achieved second milestone payment under global cardiovascular collaboration

with Bristol Myers Squibb -

SAN DIEGO, August 13, 2026 / PRNewswire/ - Atrium Therapeutics, Inc. (Nasdaq: RNA) ("Atrium," "Atrium Therapeutics," or the "Company"), a biopharmaceutical company advancing precision cardiology by developing RNA therapeutics targeted to the heart, today reported financial results for the second quarter ended June 30, 2026, and highlighted recent corporate progress including FDA clearance of its Investigational New Drug (IND) application for ATR 1072 and continued achievements under its collaboration with Bristol Myers Squibb (BMS).

"Our team continues to execute well, achieving FDA clearance of our IND for ATR 1072 and launching Corventis - Atrium's first Phase 1/2 trial and the first clinical study to evaluate a potential disease-modifying treatment for people living with PRKAG2 syndrome," said Kathleen Gallagher, President and Chief Executive Officer of Atrium Therapeutics. "Atrium's precision approach to genetic cardiomyopathies is part of a burgeoning frontier in medicine. Our experienced team is well-positioned to continue advancing and efficiently expanding our pipeline with urgency on behalf of patients and clinicians."

Recent Highlights

Anticipated Upcoming Milestones

Second Quarter 2026 Financial Results

About Atrium Therapeutics

Atrium Therapeutics, Inc. (Nasdaq: RNA) is pioneering targeted delivery of ribonucleic acid (RNA) therapeutics to the heart to transform the standard of care for people living with cardiomyopathies. With the U.S. Food and Drug Administration's (FDA) recent clearance of its Investigational New Drug (IND) application for ATR 1072 for PRKAG2 (Protein Kinase AMP-activated non-catalytic subunit Gamma 2) syndrome, Atrium is advancing its first precision cardiology program into the clinic through the Corventis Phase 1/2 clinical trial. The Company's proprietary technology - designed at Avidity Biosciences, Inc. - combines the tissue selectivity of monoclonal antibodies (mAbs) and other targeted delivery ligands with the precision of oligonucleotides and is designed to selectively target the underlying drivers of genetically driven cardiac diseases through targeted, non-viral delivery of small interfering RNA (siRNA). This approach builds upon learnings from demonstrated delivery to skeletal muscle and applies it for efficient delivery to the heart, with the potential to overcome challenges associated with non-specific tissue delivery. Beyond ATR 1072, the Company's pipeline includes ATR 1086 for PLN (phospholamban) cardiomyopathy and two undisclosed research targets in rare cardiomyopathies.

For more information about our RNA delivery platform, development pipeline and people, please visit https://atriumtherapeutics.com/ and engage with us on LinkedIn.

Availability of Other Information About Atrium Therapeutics

Investors and others should note that Atrium Therapeutics communicates with its investors and the public using its website https://atriumtherapeutics.com/, including, but not limited to, Atrium Therapeutics' disclosures, investor presentations and FAQs, Securities and Exchange Commission ("SEC") filings, press releases, public conference call transcripts and webcast transcripts, as well as on LinkedIn. The information that Atrium Therapeutics posts on its website or on LinkedIn could be deemed to be material information. As a result, Atrium Therapeutics encourages investors, the media, and others interested to review the information that it posts there on a regular basis. The contents of Atrium Therapeutics' website or social media shall not be deemed incorporated by reference in any filing under the Securities Act of 1933, as amended.

About PRKAG2 Syndrome

PRKAG2 syndrome is a rare, autosomal dominant, early-onset cardiomyopathy caused by mutations in the PRKAG2 gene, which encodes the Gamma 2 regulatory subunit of AMPK. Mutations enhance AMPK activity leading to abnormal glycogen accumulation in heart, thickened heart muscles, electrical conduction problems, and arrhythmias. Based on current scientific literature estimates, there are at least 1,000 - 2,000 people with PRKAG2 syndrome in the U.S. Current management is limited to symptomatic treatment; no approved therapies exist to address the underlying genetic driver of disease.

About PLN Cardiomyopathy

Phospholamban ("PLN") cardiomyopathy is a rare autosomal dominant, progressive cardiac disease caused by mutations in PLN, a key regulator of sarcoplasmic reticulum Ca2+-ATPase 2a ("SERCA2a") calcium pump. PLN mutations produce protein aggregates that disrupt endoplasmic reticulum processes and lead to dilated, arrhythmogenic, or hypertrophic cardiomyopathies and a significantly increased risk of heart failure and sudden cardiac death. There are 2,000 - 4,000 people with pathogenic PLN variants in the United States. No approved therapies target the underlying molecular cause of the disease.