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Atossa Therapeutics Selects PSI as Contract Research Organization for Pivotal Dose-Ranging Study of (Z)-Endoxifen in Metastatic Breast Cancer
Monotherapy Phase 2 study designed with FDA input; IND expected in Q4 2025 Topline results anticipated in 2026 Positions Atossa for transition into
About this update from Atossa Therapeutics, Inc.
[{"type":"text","content":"Monotherapy Phase 2 study designed with FDA input; IND expected in Q4 2025\nTopline results anticipated in 2026\n Positions Atossa for transition into registrational Phase 3 development\nSEATTLE, Aug. 20, 2025 /PRNewswire/ -- Atossa Therapeutics, Inc. (Nasdaq: ATOS) (\"Atossa\" or the \"Company\"), a clinical-stage biopharmaceutical company developing innovative medicines for breast cancer, announced today it has selected PSI, a leading global contract research organization (CRO), to operationalize and manage its planned (Z)-endoxifen monotherapy dose-ranging study in women with metastatic breast cancer (mBC). The study was designed following guidance from the U.S. Food and Drug Administration (FDA) and is intended to directly inform a subsequent Phase 3 trial.\n\n \n \n\n \nThe global Phase 2, multi-center dose-ranging study is designed to evaluate (Z)-endoxifen monotherapy for safety, pharmacokinetics/pharmacodynamics, and preliminary anti-tumor activity. Patient enrollment is expected to follow the Investigational New Drug (IND) filing in Q4 2025, with topline data anticipated in 2026.\n\"This is a defining milestone for Atossa,\" said Dr. Steven Quay, Chairman and Chief Executive Officer of Atossa. \"With PSI as our partner, we are advancing (Z)-endoxifen into its final steps before Phase 3. Unlike existing endocrine therapies, (Z)-endoxifen has demonstrated clinical activity even in tumors resistant to aromatase inhibitors and fulvestrant. If successful, this program could reshape the standard of care in breast cancer treatment, including in the metastatic setting, and deliver hope to patients who currently face limited options.\"\nPSI is widely recognized for excellence in global oncology trial execution with the ability to move swiftly from Phase 2 into Phase 3 trials. In 2024, 93 percent of PSI-managed studies enrolled on time or ahead of schedule, leveraging its proprietary machine-learning feasibility platform, VISIONAL™. Atossa selected PSI, following a highly competitive process, for its proven ability to:\nDeliver regulatory-grade data through rigorous quality and compliance systems.Consistently achieve on-time enrollment across diverse geographies.Seamlessly scale programs into Phase 3 and pivotal studies, often reducing operational risk and accelerating timelines.\"We are excited to partner with Atossa on this piv...