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Atossa Therapeutics Announces Issuance of U.S. Patent Covering Enteric Oral (Z)-Endoxifen Formulations and Methods of Treating Patients Using (Z)-Endoxifen
New patent further strengthens global intellectual property estate supporting Atossa's lead program across the breast cancer spectrum and other hormone-driven
About this update from Atossa Therapeutics, Inc.
[{"type":"text","content":"New patent further strengthens global intellectual property estate supporting Atossa's lead program across the breast cancer spectrum and other hormone-driven conditionsSEATTLE, Dec. 9, 2025 /PRNewswire/ -- Atossa Therapeutics, Inc. (Nasdaq: ATOS) (\"Atossa\" or the \"Company\"), a clinical-stage biopharmaceutical company developing innovative therapies in areas of significant unmet need in breast cancer, today announced that the United States Patent and Trademark Office (USPTO) issued U.S. Patent No. 12,479,790 B2, titled, \"Methods for Making and Using Endoxifen.\"\n \n \n \n \n \n \n \nThe newly issued patent includes 100 claims directed to enteric oral formulations of highly pure (Z)-endoxifen free base, as well as methods of using those compositions to treat a range of hormone-dependent breast disorders and other estrogen-related conditions. The patent also covers specific solid oral dosage forms and stable formulations providing therapeutically meaningful and sustained systemic exposure to (Z)-endoxifen.\"We believe this patent meaningfully extends and reinforces our already robust endoxifen patent estate,\" said Steven Quay, M.D., Ph.D., Atossa's President and Chief Executive Officer. \"By covering both scalable manufacturing processes and key methods of use, this patent supports our long-term strategy to position (Z)-endoxifen as a differentiated therapy across the breast cancer spectrum, from risk-reduction and neoadjuvant treatment through adjuvant and metastatic disease, while also enabling opportunities in other hormone-driven conditions. \"Together with previously issued U.S. patents covering storage-stable and sustained-release endoxifen formulations, and broader formulation patents granted earlier this year, this new patent further consolidates our leadership position in endoxifen therapeutics. A strong and durable intellectual property foundation is essential as we invest in late-stage clinical trials and potential future commercialization,\" concluded Dr. Quay.Atossa is currently advancing its proprietary (Z)-endoxifen in multiple clinical settings, including:Metastatic breast cancer (MBC): A dose-ranging study is in preparation as part of the Company's strategy to support registrational development.Neoadjuvant ER+/HER2- breast cancer: Enrollment and data generation continue in the Phase 2 EVANGELINE trial.Breas...