Atossa Therapeutics Announces ASCO 2026 Abstracts Highlighting (Z)-Endoxifen Activity Across ESR1 Mutations and Ongoing EVANGELINE Phase 2 Trial

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.