Atrium Therapeutics filings document the corporate transition that created the current RNA issuer and the related Avidity Biosciences merger, separation and listing records. The filing set includes 8-K material-event reports, shareholder voting disclosures, separation and merger agreement records, capital-structure information and a Form 25 covering removal of Avidity common stock from Nasdaq listing and registration.
Regulatory disclosures tied to the symbol also cover governance matters, operating and financial results, clinical or regulatory updates and security-structure information. As an independent biopharmaceutical company, Atrium's filings center on its RNA therapeutics platform, precision cardiology pipeline, collaboration economics, equity compensation and public-company reporting obligations.
Atrium Therapeutics, Inc. (RNA) said it will present nonclinical results for ATR 1072, its investigational PRKAG2 syndrome therapy, on November 6, 2026, at HCMS during the American Heart Association Scientific Sessions. In a company-developed mouse model, mice received one dose of mATR 1072, a mouse surrogate, after disease features had been established for three weeks. Four weeks after treatment, cardiac glycogen accumulation was reversed, while cardiac hypertrophy and ECG parameters improved.
Corventis is a Phase 1/2 open-label trial that will enroll approximately 37 participants. Atrium expects initial proof-of-concept data in the second half of 2027. The trial’s primary endpoint is treatment-emergent adverse events; secondary measures include PRKAG2 mRNA reduction and siRNA tissue concentrations.
The corporate presentation lists $264 million in cash, cash equivalents and investments as of June 30, 2026, with runway through the end of 2028. That runway excludes the $15 million milestone earned from Bristol Myers Squibb, announced August 13, 2026, and proceeds from the $50 million private placement announced October 8, 2026. It also lists $1.5 billion in potential R&D milestone payments from existing BMS and LLY collaborations, subject to the agreements’ terms and conditions.
Atrium Therapeutics, Inc. (RNA) announced that the first patient has been dosed in the Phase 1/2 Corventis trial evaluating ATR 1072, an investigational therapy for the potential treatment of PRKAG2 syndrome. The open-label, multicenter study is designed to assess safety, tolerability, pharmacokinetics, pharmacodynamics and efficacy, and is expected to enroll approximately 37 participants across multiple-ascending-dose and single-arm expansion parts.
The primary endpoint is the incidence of treatment-emergent adverse events; secondary and exploratory measures include PRKAG2 mRNA reduction, siRNA tissue concentrations and plasma pharmacokinetics. Atrium expects initial proof-of-concept data in the second half of 2027.
Atrium Therapeutics, Inc. amended its earlier 8-K to correct the post-offering count to 21,571,507 common shares outstanding. On October 7, 2026, the company entered into a securities purchase agreement with selected accredited investors to sell 5,170,384 common shares and pre-funded warrants to purchase up to 1,134,930 shares.
The post-offering count includes shares issued in connection with settlement of make-whole equity awards made in connection with the company’s spin-off from Avidity Biosciences. Atrium described the offering’s closing as expected and cited closing conditions and timing as risks.
Atrium Therapeutics, Inc. (RNA) agreed to sell 5,170,384 common shares and pre-funded warrants to purchase up to 1,134,930 shares in a private placement expected to generate approximately $50 million in gross proceeds before placement agent fees and other offering expenses.
Shares were priced at $7.93 each and warrants at $7.929 each, with a $0.001 exercise price. Warrants are exercisable after issuance and expire when exercised in full. Exercise is limited by a 9.99% ownership cap, or 4.99% at the holder’s election; after at least 61 days’ prior notice, the holder may change the cap to another percentage up to 19.99%. Closing is expected on or about October 9, 2026, subject to customary conditions.
Atrium plans to use net proceeds and existing cash, cash equivalents and marketable securities for its lead candidates, other research programs, working capital and general corporate purposes, and estimates these resources will fund operations through 2028. Following the Offering, it expects 22,276,027 common shares outstanding, including shares issued in connection with settlement of make-whole equity awards. Atrium agreed to file a resale registration statement covering the Shares and Warrant Shares within 50 days of the Closing Date.
Atrium Therapeutics, Inc. (RNA) reported that Chief Scientific Officer Younis Husam had 11,216 shares of common stock withheld on September 18, 2026 to satisfy tax withholding obligations tied to vesting restricted stock units. Following this tax-withholding disposition, he directly holds 41,441 shares of Atrium common stock.
Atrium Therapeutics, Inc. (RNA) reported that Chief Medical Officer Steven George Hughes had 21,459 shares51,638 shares
Atrium Therapeutics, Inc. (RNA) director Michael W. Flanagan reported a Form 4 reflecting the withholding of 22,812 shares of Common Stock on September 18, 2026 to satisfy tax withholding obligations arising from the vesting of restricted stock units. After this tax-withholding disposition, he holds 31,974 shares of Common Stock directly.
Atrium Therapeutics, Inc. (RNA) reported that director Sarah Boyce had 126,418 shares of Common Stock withheld on September 18, 2026 to satisfy tax withholding obligations arising from the vesting of restricted stock units. After this withholding transaction, she directly holds 138,668 shares of Atrium Therapeutics common stock. No Rule 10b5-1 trading plan is reported for this Form 4.
Atrium Therapeutics, Inc. (RNA) reported that Chief Corporate Affairs Officer Stephanie Kenney had 2,375 shares of common stock withheld on September 18, 2026 to satisfy tax withholding obligations arising from vesting of restricted stock units. After this tax-withholding disposition, she directly holds 33,085 shares of common stock. No Rule 10b5-1 plan is reported.
Atrium Therapeutics, Inc. (RNA) reported that Chief Executive Officer, President and director Kathleen P. Gallagher had 11,632 shares of common stock withheld on September 18, 2026 to satisfy tax withholding obligations related to vesting restricted stock units. These shares were not sold in the market, and she continued to hold 119,729 shares of common stock directly afterward.