Atossa Therapeutics

ATOS

Market cap $49.4M

SEATTLE, March 25, 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 announces its financial results for the fourth quarter and year ended December 31, 2025 and provides an update on recent corporate developments. "While we have consistently made meaningful and measurable progress across our (Z)-endoxifen development strategy in oncology over the last 12 months, we continue to explore the best opportunities to leverage the technology where it may help to address serious health conditions and unmet medical needs.

Kathy Puyana Theall, M.D. and Adebola Giwa, M.D.

Study Highlights Findings that (Z)-endoxifen Restores Muscle Performance and Lowers Damage Biomarkers in mdx5Cv Dystrophic Mice SEATTLE, March 12, 2026 /PRNewswire/ -- Atossa Therapeutics, Inc. (Nasdaq: ATOS) ("Atossa" or the "Company"), a clinical-stage biopharmaceutical company developing novel therapies in oncology and other rare disease indications with significant unmet need, presented an oral clinical trial update on (Z)-endoxifen at the MDA Clinical & Scientific Conference on March 11, 2026, in Orlando, FL. Presentation Highlights The mdx5Cv Dystrophic mouse model, a trusted, reproducible standard for Duchenne muscular dystrophy (DMD) preclinical research, was used for this study (Z)-Endoxifen improved muscle strength and motor performance in both juvenile and adult dystrophic mice Treatment enhanced resistance to contraction-induced muscle injury Favorable changes were observed in body composition, including increased lean mass and reduced fat mass Key biochemical and histologic markers of muscle damage were reduced The therapy was well tolerated with no adverse findings observed during the study Clinical Significance DMD is a progressive and ultimately fatal neuromuscular disorder characterized by ongoing muscle degeneration, inflammation, and fibrosis.

SEATTLE, Feb. 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 need, today issued a letter to Shareholders from Steven Quay, M.D., Ph.D., Atossa Therapeutics President and Chief Executive Officer, providing an update on the Company's clinical programs and recent events.

Atossa's Rare Pediatric Disease Designation for (Z)-endoxifen in neuromuscular diseases qualifies for a future PRV upon FDA approval SEATTLE, Feb. 5, 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 reaffirmed its strong market position around its Duchenne Muscular Dystrophy (DMD) program following  yesterday's congressional announcement that it had passed a five-year reauthorization of the Rare Pediatric Disease Priority Review Voucher ("PRV") Program. The program extends the Company's ability to be eligible to receive a future PRV upon the U.S. Food and Drug Administration's ("FDA") approval following the FDA granting Rare Pediatric Disease ("RPD") designation to (Z)-endoxifen for the treatment of DMD late last year.

Recognized for Visionary Leadership and Advancing Innovative Therapies in Oncology and Healthcare Technology SEATTLE, Jan. 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 high unmet clinical need, announces that Founder, Chairman, President, and Chief Executive Officer Steven Quay, M.D., Ph.D. has been selected as one of "The Top 50 Healthcare Technology CEOs of 2025" by The Healthcare Technology Report.

Designation further supports (Z)-Endoxifen program into rare pediatric neuromuscular disease along with previously received Rare Pediatric Disease Designation SEATTLE, Jan. 16, 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 the U.S. Food and Drug Administration ("FDA") Office of Orphan Products Development ("OOPD") has granted Orphan Drug Designation to (Z)-endoxifen for the treatment of Duchenne muscular dystrophy ("DMD"). "In addition to the previously received Rare Pediatric Disease designation, Orphan Drug Designation for (Z)-endoxifen in Duchenne muscular dystrophy is an important milestone for Atossa as we move forward developing (Z)-endoxifen for this serious and debilitating disease," noted Steven C.

SEATTLE, Jan. 6, 2026 /PRNewswire/ -- Atossa Therapeutics, Inc. (Nasdaq: ATOS), a clinical-stage biopharmaceutical company developing innovative medicines for unmet medical needs, today announced that the U.S. Food and Drug Administration ("FDA") issued a "Study May Proceed" letter for the Company's study in metastatic breast cancer which was the subject of a recent investigational new drug application for (Z)-endoxifen. "This letter marks an important regulatory milestone for Atossa and to potentially expand the use of (Z)-endoxifen for metastatic ER+/HER2- Breast Cancer.

Recognized for Advancing (Z)-Endoxifen, a Precision-Engineered Endocrine Therapy with Potential Across Multiple Breast Cancer and Rare Disease Settings SEATTLE , Dec. 17, 2025 /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, announces that it has been selected as a winner of the 2025 Clinical Trials Arena Excellence Awards. The Company was honored with the Research and Development Award in the Precision Endocrine Therapy category.

Studies highlight findings regarding the potential use of (Z)-endoxifen to advance breast cancer treatment and risk reduction SEATTLE , Dec. 15, 2025 /PRNewswire/ -- Atossa Therapeutics, Inc. (Nasdaq: ATOS) ("Atossa" or the "Company"), a clinical-stage biopharmaceutical company developing innovative medicines in oncology and other areas of high unmet need, presented four clinical trial updates on (Z)-endoxifen at the San Antonio Breast Cancer Symposium (SABCS), held December 9-12, 2025, in San Antonio, TX. "Clinical trial updates and data presented at SABCS 2025 reinforce our focus on the therapeutic value of (Z)-endoxifen across the breast care continuum," said Steven Quay, M.D.