Atossa Therapeutics, Inc.'s SEC filings document a clinical-stage biopharmaceutical issuer focused on (Z)-endoxifen development in oncology and rare disease settings. Its reports include financial-result 8-Ks, corporate updates, Regulation FD communications, and disclosures tied to research and development spending for its lead product candidate.
The filing record also covers governance and capital-structure matters, including annual meeting votes, director elections, auditor ratification, executive-compensation votes, charter-authority proposals, Form S-3 and at-the-market offering disclosures, Nasdaq listing compliance, and material events involving Endoxifen-related intellectual property proceedings and settlement agreements.
Atossa Therapeutics, Inc. is asking stockholders to vote at its virtual 2026 annual meeting on May 7, 2026. Proposals include electing three Class II directors, ratifying Ernst & Young LLP as auditor for 2026, an advisory vote on executive pay, and a possible meeting adjournment to gather more proxies.
The Board is also seeking advance approval to implement, at its discretion within one year, a reverse stock split of the common stock at a ratio between 2:1 and 20:1, solely if needed to maintain compliance with Nasdaq’s minimum bid price rules. The company previously effected a 15:1 reverse split effective February 2, 2026. Common shares outstanding were 8,611,361 as of the March 19, 2026 record date, each entitled to one vote.
Atossa Therapeutics files its annual report as a clinical‑stage biotech focused on breast cancer and related conditions, led by its oral (Z)-endoxifen program in multiple Phase 2 trials and exploratory rare-disease indications including Duchenne muscular dystrophy (DMD) and McCune‑Albright Syndrome.
The company reports research and development expenses of approximately $21.2 million for 2025, up from $14.1 million in 2024, and cash and cash equivalents of about $41.3 million as of December 31, 2025. Management states there is substantial doubt about its ability to continue as a going concern without additional capital, and it does not expect revenue until its drug candidates are approved and commercialized.
To strengthen its financial position and maintain listing, Atossa effected a 1‑for‑15 reverse stock split in February 2026 to regain compliance with Nasdaq’s minimum bid requirement and established a new at‑the‑market facility allowing sales of up to $50,000,000 of common stock. During 2025 all outstanding warrants expired, simplifying the capital structure.
Atossa Therapeutics reported a larger net loss of $34.8M for the year ended December 31, 2025, compared with $25.5M a year earlier, as it increased investment in its lead drug candidate, (Z)-endoxifen.
Total operating expenses rose to $37.1M from $27.6M. Research and development spending climbed 50% to $21.2M, driven mainly by an extra $6.1M on clinical and non-clinical trials and higher regulatory consulting tied to (Z)-endoxifen. General and administrative costs increased 18% to $16.0M, reflecting higher legal expenses related to litigation and patent defense and modestly higher compensation.
The company ended 2025 with cash and cash equivalents of $41.3M, down from $71.1M as it funded operations, while interest income fell to $2.4M from $4.1M due to lower average invested balances. During the year, Atossa secured FDA Rare Pediatric Disease and Orphan Drug designations for (Z)-endoxifen in Duchenne Muscular Dystrophy and strengthened its clinical leadership team to support both breast cancer and rare disease programs.
Atossa Therapeutics, Inc. is soliciting proxies for its 2026 virtual Annual Meeting of Stockholders to be held May 7, 2026, where holders of common stock of record on March 19, 2026 will vote on director elections and several governance matters. The Record Date shows 8,611,361 shares outstanding.
Key items include: (1) election of three Class II directors; (2) ratification of Ernst & Young LLP as auditor; (3) approval of a Certificate of Incorporation amendment authorizing a board-discretion reverse stock split at a ratio of 2:1 to 20:1 to be implemented within one year if the Board deems necessary to maintain Nasdaq listing; (4) advisory approval of executive compensation; and (5) adjournment authority to solicit additional proxies. The Board recommends a vote FOR each proposal. The Proxy Statement notes a prior reverse split at a 15:1 ratio effective February 2, 2026, and states per-share figures are presented on a post-split basis.
Atossa Therapeutics, Inc. entered into a new at-the-market equity offering agreement with Rodman & Renshaw LLC, allowing the company to sell up to $50,000,000 of its common stock from time to time. Shares will be issued under an existing Form S-3 shelf registration and a related prospectus supplement.
Rodman & Renshaw will act as sales agent or principal and earn a commission of up to 3.0% of gross proceeds, plus reimbursed expenses. Atossa plans to use any proceeds mainly for clinical development of its product candidates, as well as working capital and general corporate purposes, with potential future business or asset acquisitions.
The company also terminated its prior Open Market Sale agreement with Jefferies LLC, effective February 19, 2026, incurring no termination penalties and having sold no shares under that earlier arrangement.
Atossa Therapeutics, Inc. has filed a prospectus supplement to sell up to $50,000,000 of its common stock through an at-the-market offering with Rodman & Renshaw LLC under a Sales Agreement. Sales may occur from time to time on Nasdaq or by other permitted methods and Rodman will receive up to a 3.0% commission on gross sales.
The prospectus notes 8,611,428 shares outstanding as of September 30, 2025 and states that all share and per-share amounts in the supplement reflect a 15:1 reverse stock split effective February 2, 2026. Proceeds, if any, are intended for clinical development, working capital and general corporate purposes; actual proceeds depend on the timing and market prices of sales.
Atos Therapeutics, Inc. amended its ATM facility. The prospectus supplement states the company reduced the Maximum Offering Price under its Open Market Sale with Jefferies LLC from $100,000,000 to $0, effective as of February 20, 2026.
No shares have been sold under the ATM Facility as of the date of the supplement.
Atossa Therapeutics, Inc. received notice from Nasdaq on February 17, 2026 that it has regained compliance with the Nasdaq Capital Market’s minimum bid price listing rule. The company’s stock met the requirement to maintain a closing bid price of at least $1.00 per share for 10 consecutive trading days, achieved as of the close on February 13, 2026.
Atossa had previously been notified on February 21, 2025 that it was out of compliance with the $1.00 minimum bid price and was granted an extension through February 17, 2026 to correct the deficiency. With compliance restored, the company’s common stock will continue to be listed and traded on the Nasdaq Capital Market.
Atossa Therapeutics furnished an 8-K to share its 2026 Letter to Shareholders, outlining progress and plans for lead candidate (Z)-endoxifen. The company highlighted a late-2025 FDA Type C meeting that clarified expedited regulatory options in multiple breast cancer settings and ongoing I-SPY 2 neoadjuvant studies, with preliminary combination-therapy data expected in 2026. Atossa obtained Rare Pediatric Disease and Orphan Drug designations for (Z)-endoxifen in Duchenne Muscular Dystrophy, and is exploring additional non-oncology uses. Management paused investment in metastatic breast cancer trials to prioritize higher-return indications, strengthened its leadership team, and reported entering 2026 with more than $40 million in cash and cash equivalents. The company also completed a reverse stock split effective February 2, 2026 to help regain Nasdaq listing compliance.
Atossa Therapeutics President and CEO Steven C. Quay filed an amended Form 4 updating an equity award reported for January 20, 2026. The filing now shows he acquired 331,674 restricted stock units, each representing one share of common stock, vesting one year after the grant date.
Following the transaction, he holds 345,572 common shares directly and 22,254 shares indirectly through Ensisheim Partners, LLC, which he co-owns with Dr. Shu-Chih Chen. The amendment also reports a grant of 950,000 stock options at an exercise price of $0.603, vesting quarterly over 24 months beginning January 20, 2026.