Atrium Therapeutics, Inc. filed Amendment No. 1 to its Form 8-K to correct the number of shares outstanding following a private investment in equity securities (PIPE) offering. The San Diego-based company stated that no other information from the original report filed on October 8, 2026, was revised.
The amendment addresses the securities purchase agreement signed on October 7, 2026, with selected accredited investors under Rule 501(a) of Regulation D. Under the agreement, Atrium agreed to sell an aggregate of 5,170,384 shares of common stock, par value $0.001 per share, and pre-funded warrants to purchase up to 1,134,930 additional shares. The company identified this transaction as the Offering.
According to the filing, Atrium will have 21,571,507 shares of common stock outstanding following the completion of the Offering. This total includes shares issued in connection with the settlement of make whole equity awards related to the company's spin-off from Avidity Biosciences, Inc. The original Form 8-K contained a different figure for the post-offering share count, which this amendment corrects.
Atrium Therapeutics is registered on the Nasdaq Global Select Market under the ticker symbol RNA. The company is incorporated in Delaware and designated as an emerging growth company in its SEC filings. Kathleen Gallagher, Chief Executive Officer, signed the amendment on October 9, 2026.
The filing includes forward-looking statements regarding the expected closing of the Offering. Atrium noted that actual results could differ from expectations due to risks related to the ability of the company or investors to satisfy closing conditions and the timing of the closing. The company pointed to risk factors described in its Quarterly Reports on Form 10-Q for the periods ended March 31, 2026, and June 30, 2026, as well as future SEC filings.