Exhibit 99.1 Atossa Therapeutics Reports Third Quarter 2025 Financial Results and Provides a Corporate Update Company reports progress to file planned IND for (Z)-endoxifen in mBC with CRO selection and streamlined development programs for potential 2026-NDA enabling activities, including a Type C meeting with the FDA, to potentially accelerate (Z)- endoxifen in breast cancer risk reduction SEATTLE, November 12, 2025 — Atossa Therapeutics, Inc. (Nasdaq: ATOS) (Atossa or the Company), a clinical-stage biopha ...