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 whose news flow centers on the development of its lead investigational therapy, (Z)-Endoxifen. Company announcements frequently cover progress in breast cancer programs, regulatory interactions, intellectual property developments, and emerging opportunities in other serious diseases.
Investors following ATOS news can expect regular updates on clinical trials involving (Z)-Endoxifen, including studies in metastatic ER+/HER2- breast cancer, neoadjuvant treatment for premenopausal ER+/HER2- patients, breast cancer risk reduction strategies focused on mammographic breast density, and participation in the RECAST DCIS platform trial for hormone receptor–positive ductal carcinoma in situ. These releases often summarize trial design, early findings, and the potential implications for future registration strategies.
Atossa’s news also highlights regulatory milestones, such as FDA Type C meetings, Investigational New Drug (IND) submissions, and “Study May Proceed” letters. Additional coverage includes the FDA’s Rare Pediatric Disease designation for (Z)-Endoxifen in Duchenne Muscular Dystrophy, as well as AI-enabled research collaborations identifying new oncology indications like glioblastoma.
Another recurring theme in ATOS news is the company’s intellectual property position, including newly issued patents for enteric oral (Z)-Endoxifen formulations and methods of use in hormone-dependent breast disorders and estrogen-related conditions. Corporate updates, such as financial results, leadership appointments, and Nasdaq listing communications, provide context on Atossa’s operational and strategic direction.
By monitoring this news page, readers can review a chronological record of Atossa’s clinical, regulatory, scientific, and corporate announcements related to (Z)-Endoxifen and the company’s broader oncology and rare disease programs.
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.
Atossa Therapeutics (NASDAQ: ATOS) has released its full year 2024 financial results, ending with $71.1 million in cash and no debt. The company announced a strategic shift to focus on metastatic breast cancer for its lead program, (Z)-endoxifen.
Key highlights include positive data from the Phase 2 EVANGELINE trial, showing tumor suppression rates above 85% across dose levels. The trial will continue with amended protocol comparing 40mg (Z)-endoxifen with OFS to exemestane plus OFS. The Phase 2 KARISMA-Endoxifen study demonstrated significant mammographic breast density reduction, with 1mg and 2mg doses achieving 17.3 and 23.5 percentage point reductions respectively.
Financial results show total operating expenses decreased by $3.8 million to $27.6 million in 2024, compared to $31.4 million in 2023. Interest income was $4.1 million, down $0.2 million from the previous year.
Atossa Therapeutics (NASDAQ: ATOS), a clinical-stage biopharmaceutical company focused on breast cancer medicines, has scheduled its fourth quarter and full year 2024 financial results conference call for Tuesday, March 25, 2025, at 8:30 a.m. ET.
The company will host both a conference call and live audio webcast to discuss corporate and financial results. Investors can access the webcast through the investor relations section of Atossa's website. For telephone access, U.S. callers should dial 1-800-836-8184, while international participants can dial 1-646-357-8785. The conference call name is 'Atossa Therapeutics Business Update'. A 30-day replay will be available on the company's website following the call.
Atossa Therapeutics (NASDAQ: ATOS) has announced its strategic focus on developing (Z)-endoxifen for metastatic breast cancer treatment, while simultaneously pursuing additional indications with FDA guidance.
Early clinical trials have shown promising results, with (Z)-endoxifen demonstrating:
- More than doubled median progression-free survival compared to tamoxifen (7.2 vs. 2.4 months) in CDK4/6i-naïve patients
- Clinical benefits in patients who progressed on tamoxifen, including partial responses and stable disease lasting 2-3 years
- Favorable safety profile comparable to tamoxifen
The company is also advancing additional indications including breast cancer prevention and neoadjuvant therapy. In early-stage patients, (Z)-endoxifen maintained a Ki-67 ≤10% response rate above 85% across all dose levels, suggesting effective tumor proliferation reduction.
Atossa Therapeutics (Nasdaq: ATOS) announces that board director Dr. Tessa Cigler and Weill Cornell Medicine have been awarded a $2.3 million CDC grant over five years. The grant aims to improve breast cancer care for young patients across New York City, focusing on equitable access, quality of life, and survival outcomes.
Dr. Cigler, who serves as Associate Professor of Clinical Medicine at Weill Cornell Medicine and co-principal investigator, will collaborate with Dr. Vered Stearns to enhance care coordination and provide culturally relevant resources. The initiative specifically targets patients from diverse racial, ethnic, and socio-economic backgrounds, implementing interventions to optimize physical, emotional, and mental well-being for both patients and caregivers.