ATOS

One CVR will attach to each outstanding share of Atossa common stock as of the close of business on October 19, 2026, and shares and CVRs will transfer together while stapled Shares issued after October 19, 2026 will also carry one attached CVR, subject to the terms of the CVR Agreement SEATTLE, Oct. 19, 2026 /PRNewswire/ -- Atossa Therapeutics, Inc. (Nasdaq: ATOS) ("Atossa" or the "Company"), a clinical-stage biopharmaceutical company developing innovative medicines in oncology and other areas of significant unmet need, today confirmed that each outstanding share of Atossa common stock will begin trading with one stapled contingent value right ("CVR") as of the close of business today, October 19, 2026. Under the terms of the Stapled Contingent Value Rights Agreement (the "CVR Agreement") with VStock Transfer, LLC, as rights agent, each share of Atossa common stock outstanding at the close of business on October 19, 2026 will receive, and have attached, one CVR.

Board declares one stapled CVR for each share of Atossa common stock outstanding as of October 19, 2026 record date or issued thereafter CVRs entitle holders to 25% of net proceeds from monetization of Atossa's first qualifying priority review voucher, subject to a $50 million aggregate payment cap SEATTLE, Oct. 9, 2026 /PRNewswire/ -- Atossa Therapeutics, Inc. (Nasdaq: ATOS) ("Atossa" or the "Company"), a clinical-stage biopharmaceutical company developing innovative medicines in oncology and other areas of significant unmet need, today announced that it has entered into a definitive Stapled Contingent Value Rights Agreement (the "CVR Agreement") with VStock Transfer, LLC, as rights agent, implementing the stapled contingent value rights ("CVRs") plan previously announced on September 29, 2026. In connection with the execution of the CVR Agreement, Atossa's Board of Directors declared a dividend of one stapled CVR for each share of Atossa common stock outstanding at the close of business on October 19, 2026, the record date.

Panel at Harvard University will explore translating evidence in diseases of aging into new therapeutics and regulatory pathways SEATTLE, Sept. 24, 2026 /PRNewswire/ -- Atossa Therapeutics, Inc. (Nasdaq: ATOS) ("Atossa" or the "Company"), a clinical-stage biopharmaceutical company, today announced that Steven Quay, M.D.

SEATTLE, Aug. 7, 2026 /PRNewswire/ -- Atossa Therapeutics, Inc. (Nasdaq: ATOS) (Atossa or the Company), a clinical-stage biopharmaceutical company developing novel therapies in oncology and other areas of high unmet clinical need, today announced its financial results and provided an update on recent corporate developments for the second quarter ended June 30, 2026. "During the quarter, we executed well across the business," stated Dr. Steven Quay, M.D.

Peer-reviewed preclinical study published in npj Breast Cancer identifies new chemical entities with activity in ESR1-mutant models Findings suggest potential for combination with abemaciclib SEATTLE, July 28, 2026 /PRNewswire/ -- Atossa Therapeutics, Inc. (NASDAQ: ATOS) ("Atossa" or the "Company"), a clinical-stage biopharmaceutical company developing novel therapies in oncology and other areas of significant unmet clinical need, today announced the publication of a peer-reviewed preclinical study in npj Breast Cancer evaluating five novel chemical entities structurally related to (Z)-endoxifen. The study titled, "Novel (Z)-endoxifen-related new chemical entities exhibit potent anti-cancer activity in ERα+ breast cancer," reported anti-estrogenic and anti-cancer activity across multiple estrogen receptor-positive breast cancer models, including models harboring clinically relevant activating mutations in ESR1.

Preclinical Data Poster Highlights Dual Estrogen Receptor and PKC-β/AKT Pathway Modulation as a Potential Therapeutic Strategy for Estrogen-Driven Pathology in McCune-Albright syndrome SEATTLE, July 21, 2026 /PRNewswire/ -- Atossa Therapeutics, Inc. (NASDAQ: ATOS) ("Atossa" or the "Company"), a clinical-stage biopharmaceutical company developing novel therapies in oncology and other areas of significant unmet clinical need, today announced that a poster presentation titled "Dual estrogen receptor and PKC-β signaling modulation by (Z)-Endoxifen: A mechanism-driven therapeutic strategy for estrogen-driven pathology in McCune-Albright Syndrome" was presented at the AACR Special Conference in Cancer Research: Breaking Barriers in the Fight Against Rare Cancers, which took place July 18-20, 2026, in Vancouver, BC, Canada. Presentation Details Session Type: Poster Session A Date: Saturday, July 18, 2026, 7:30-9:30 pm PT Abstract Number: A010  Location: AACR Special Conference in Cancer Research: Breaking Barriers in the Fight Against Rare Cancers, Vancouver, BC, Canada Poster Title: Dual estrogen receptor and PKC-β signaling modulation by (Z)-Endoxifen: A mechanism-driven therapeutic strategy for estrogen-driven pathology in McCune-Albright Syndrome  Presenter: Sandra Hammer, PhD, Atossa Therapeutics Inc. Summary: The poster supports a dual mechanism of action for (Z)-endoxifen in estrogen-driven pathology relevant to McCune Albright Syndrome-associated Peripheral Precocious Puberty (MAS-PPP): the blockade of ER-mediated transcription downstream of autonomous estrogen production and suppression of PKC-β/AKT-associated proliferative and cell-cycle signaling.

$4.5 million upfront with up to an additional $12 million of potential aggregate gross proceeds upon exercise in full of warrants SEATTLE, June 12, 2026 /PRNewswire/ -- Atossa Therapeutics, Inc. (Nasdaq: ATOS) ("Atossa" or the "Company"), a clinical-stage biopharmaceutical company developing novel therapies in oncology and other areas of high unmet clinical need, today announced the closing of its previously announced registered direct offering of 1,363,637 shares (the "Shares") of its common stock, par value $0.18 per share ("Common Stock") (or common stock equivalents in lieu thereof), Series A warrants to purchase up to 1,363,637 shares of Common Stock and short-term Series B warrants to purchase up to 1,363,637 shares of Common Stock (such warrants, collectively, the "Series Warrants") and accompanying Series Warrants. The Series Warrants are exercisable six months following the date of issuance.

$4.5 million upfront with up to an additional $12 million of potential aggregate gross proceeds upon exercise in full of warrants SEATTLE, June 11, 2026 /PRNewswire/ -- Atossa Therapeutics, Inc. (Nasdaq: ATOS) ("Atossa" or the "Company"), a clinical-stage biopharmaceutical company developing novel therapies in oncology and other areas of high unmet clinical need, today announced that it has entered into a securities purchase agreement with institutional investors for the purchase and sale of 1,363,638 shares (the "Shares") of its common stock, par value $0.18 per share ("Common Stock") (or common stock equivalents in lieu thereof), Series A warrants to purchase up to 1,363,638 shares of Common Stock and short-term Series B warrants to purchase up to 1,363,638 shares of Common Stock (such warrants, collectively, the "Series Warrants") and accompanying Series Warrants in a registered direct offering. The Series Warrants will be exercisable six months following the date of issuance.

Preclinical Data Abstract Demonstrates Robust Estrogen Receptor (ER) Inhibition in ESR1-Mutant Breast Cancer Models at Clinically Relevant Concentrations Trial-in-Progress Abstract Details Ongoing Phase 2 EVANGELINE Study of (Z)-Endoxifen Plus Goserelin as Neoadjuvant Therapy in Premenopausal Women With ER+/HER2- Breast Cancer SEATTLE, May 27, 2026 /PRNewswire/ -- Atossa Therapeutics, Inc. (Nasdaq: ATOS) ("Atossa" or the "Company"), a clinical-stage biopharmaceutical company developing novel therapies in oncology and other areas of significant unmet medical need, today announced that two abstracts featuring (Z)-endoxifen have been accepted for presentation at the 2026 American Society of Clinical Oncology (ASCO) Annual Meeting, being held May 29 to June 2, 2026 in Chicago, IL. "Both abstracts highlight the scientific rationale and ongoing clinical development of (Z)-endoxifen in ER-positive breast cancer," said Dr. Steven C.

Review article accepted for publication in Degenerative Neurological and Neuromuscular Disease and builds on Atossa's previously published Duchenne Muscular Dystrophy (DMD) research SEATTLE, May 20, 2026 /PRNewswire/ -- Atossa Therapeutics, Inc. (NASDAQ: ATOS) (Atossa or the Company), a clinical-stage biopharmaceutical company developing novel therapies in oncology and other areas of significant unmet clinical need, today announced that the manuscript titled, "(Z)-Endoxifen as a Potential Modulator of Utrophin Pathways in Duchenne Muscular Dystrophy: A Mechanistic and Transcriptomic Perspective," has been accepted for publication in Degenerative Neurological and Neuromuscular Disease. The review centers on utrophin, a structural and functional homolog of dystrophin.