Welcome to our dedicated page for Atossa Therapeutics news (Ticker: ATOS), a resource for investors and traders seeking the latest updates and insights on Atossa Therapeutics stock.
Atossa Therapeutics Inc (NASDAQ: ATOS) is a clinical-stage biopharmaceutical company pioneering novel therapies for breast cancer and breast health conditions. This page provides investors and healthcare stakeholders with comprehensive access to official press releases, clinical trial developments, and regulatory updates directly from the company.
Track progress on key initiatives including (Z)-endoxifen clinical trials, innovative drug delivery systems like intraductal microcatheter technology, and strategic partnerships. Our curated news collection ensures timely updates on FDA communications, research milestones, and intellectual property developments relevant to oncology therapeutics.
Discover updates across three primary categories: clinical research advancements in estrogen receptor-targeted treatments, regulatory filings for breast cancer therapies, and scientific collaborations enhancing drug delivery platforms. Each update is sourced from verified company communications to maintain accuracy and compliance.
Bookmark this page for streamlined access to Atossa's latest developments in selective estrogen receptor modulation and precision medicine. Regularly updated to serve as your primary resource for understanding the company's progress in addressing unmet needs in oncology care.
Atossa Therapeutics (NASDAQ:ATOS) reported significant progress in Q2 2025, highlighted by positive FDA feedback for its (Z)-endoxifen breast cancer treatment program. The FDA cleared the path for IND filing in Q4 2025, confirming no additional toxicity studies are required.
The company's I-SPY2 trial showed strong results, with 95% of subjects completing planned dosing and median Ki-67 dropping from 10.5% to 5% by Week 3. Tumor volume decreased by 77.7% from baseline to surgery. Financial results showed R&D expenses increased 55% to $5.5 million in Q2 2025, while G&A expenses remained stable at $3.5 million.
Atossa strengthened its patent portfolio with new U.S. Patent No. 12,281,056, although two patents face challenges. The company maintains a strong cash position and has deliberately avoided using its ATM facility at current share price levels.
Atossa Therapeutics (NASDAQ: ATOS) received positive FDA feedback regarding their proposed dose optimization trial of (Z)-endoxifen for treating ER+/HER2- metastatic breast cancer. The FDA's written responses affirmed key elements of Atossa's clinical development plan, eliminating the need for a pre-IND meeting.
Key developments include: FDA approval of the dose optimization strategy, support for combination studies with standard-of-care therapies, confirmation of adequate nonclinical data package, and agreement on cardiac safety assessments. The company plans to submit an IND in Q4 2025 and will soon announce specific details about the target patient population and trial design.
The development aligns with FDA's Project Optimus initiative, which emphasizes data-driven dose exploration to maximize benefits while minimizing toxicity.
Atossa Therapeutics (NASDAQ:ATOS) will host a live investor webinar and Q&A session on May 22, 2025, at 4:15 p.m. ET. The event, hosted by RedChip Companies, will feature CEO Dr. Steven Quay discussing the company's lead clinical candidate, (Z)-endoxifen, a next-generation SERM targeting metastatic breast cancer. The presentation will cover multiple ongoing Phase 2 studies showing strong clinical activity, improved tolerability, and favorable safety profiles. Investors will learn about recent progress, upcoming milestones, and how Atossa's differentiated science and capital-efficient model aim to create clinical impact and shareholder value.
Atossa Therapeutics (NASDAQ: ATOS) has reported full results from its Phase 2 Endocrine Optimization Pilot sub-study within the I-SPY 2 TRIAL, evaluating low-dose oral (Z)-endoxifen for treating stage II/III ER+, HER2-negative breast cancer. The study achieved its primary feasibility goal with 95% of participants completing at least 75% of planned dosing. Key findings showed median Ki-67 reduction from 10.5% to 5% by Week 3, and median functional tumor volume decreased 77.7%. The treatment demonstrated a favorable safety profile with mostly Grade 1 adverse events.
However, no participants achieved pathologic complete response (pCR), with residual cancer burden classes showing moderate to extensive residual disease. This was expected due to the intentionally low 10mg dose. Atossa is now enrolling participants for additional I-SPY 2 cohorts testing higher doses (40mg) of (Z)-endoxifen, both alone and combined with abemaciclib, with top-line data expected in 2026.
Atossa Therapeutics (Nasdaq: ATOS) has secured a significant patent victory with the issuance of U.S. Patent No. 12,281,056 by the USPTO. The patent includes 58 claims covering (Z)-endoxifen formulations and therapeutic methods for their use.
The new patent specifically protects highly pure and stable enteric oral formulations of (Z)-endoxifen, a potent Selective Estrogen Receptor Modulator (SERM). This development strengthens Atossa's intellectual property portfolio in breast cancer treatment innovation.
Led by CEO Steven Quay, M.D., Ph.D., the company continues to expand its patent estate, which now includes multiple U.S. patents with over 200 patent claims related to (Z)-endoxifen formulations and clinical applications. This strategic protection reinforces Atossa's position in developing targeted therapies for hormone receptor-positive breast cancer.
Atossa Therapeutics has proposed a groundbreaking Phase 3 clinical study called SMART 2.0 at the AACR 2025 Annual Meeting. The study aims to investigate (Z)-endoxifen, a Selective Estrogen Receptor Modulator (SERM), for reducing interval breast cancer in high-risk women.
Key highlights:
- The study targets interval breast cancers, which occur between regular mammography screenings and are typically more aggressive
- Low-dose (1mg) Z-endoxifen reduced mammographic density by nearly 20% at six months in Phase 2 KARISMA trial
- Side effects were not statistically different from placebo
- The proposed trial will use AI Risk modeling to identify and randomize participants
- Primary endpoint: measuring reduction in interval breast cancer incidence over two years
This research represents a potential advancement in breast cancer prevention, offering a safer alternative to existing treatments like tamoxifen.
Atossa Therapeutics (NASDAQ: ATOS) has been granted a new U.S. Patent (No. 12,275,684) by the USPTO for enteric oral formulations of (Z)-endoxifen and related treatment methods. The patent specifically covers formulations and their use in treating hormone-dependent breast and reproductive tract disorders.
This development strengthens Atossa's intellectual property portfolio for its proprietary (Z)-endoxifen, a potent Selective Estrogen Receptor Modulator (SERM). The company's patent estate now includes multiple U.S. patents with over 100 claims related to (Z)-endoxifen formulations and clinical applications, reinforcing their position in developing targeted therapies for hormone receptor-positive breast cancer.
Nona Biosciences and Atossa Therapeutics (Nasdaq: ATOS) have announced a research collaboration to develop next-generation therapeutic antibodies for breast cancer. The partnership will utilize Nona's proprietary H2L2 Harbour Mice® platform, which generates fully human monoclonal antibodies without requiring additional engineering or humanization.
The platform combines transgenic mice technology with single B cell cloning, offering an efficient approach to therapeutic antibody development. The Harbour Mice® platform has been implemented in over 250 drug discovery programs across multiple therapeutic areas and has gained widespread recognition from global partners.
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