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 (ATOS) is a clinical-stage biopharmaceutical company developing breast cancer therapies and targeted delivery technologies. The company's news flow reflects its position as an oncology-focused biotech advancing multiple programs through clinical development and regulatory pathways. Investors tracking Atossa Therapeutics can expect news spanning clinical trial results, regulatory interactions with the FDA, intellectual property developments, research partnerships, and quarterly financial reports.
Clinical development milestones represent the most significant category of news for Atossa Therapeutics. Updates on the endoxifen program—including patient enrollment, data readouts, and trial progression—directly impact the company's valuation and strategic direction. Similarly, developments in the intraductal microcatheter technology platform generate news when the company announces new therapeutic applications, partnership agreements, or technical achievements. These clinical and technological updates often include details about FDA feedback, regulatory designations such as Fast Track or Orphan Drug status, and advancement to new trial phases.
Regulatory news constitutes another major category, as interactions with the FDA and other regulatory bodies shape the company's development timeline and commercial prospects. This includes announcements of FDA meetings, guidance received on trial design, regulatory strategy updates, and submissions of clinical trial applications. Patent issuances and intellectual property developments also generate news, as these filings protect the company's therapeutic compounds and delivery technologies and can signal the breadth of potential applications for its platforms.
Research collaborations and strategic partnerships produce news when Atossa Therapeutics engages with contract research organizations, academic institutions, or biotechnology companies to advance its pipeline. These announcements often detail the scope of collaboration, the specific technologies or capabilities being contributed by each partner, and the therapeutic objectives of the joint effort. Financial news—including quarterly earnings reports, capital raises through equity offerings, and updates on cash runway—provides insight into the company's operational trajectory and ability to fund ongoing clinical programs.
Executive appointments, analyst coverage, and investor presentation announcements round out the news profile, offering context on the company's leadership team and its communication with the investment community. For investors evaluating Atossa Therapeutics, regular monitoring of this news flow provides visibility into clinical progress, regulatory momentum, and financial sustainability—the key determinants of value for clinical-stage biopharmaceutical companies.
Atossa Therapeutics (Nasdaq: ATOS) announced on January 6, 2026 that the U.S. Food and Drug Administration issued a "Study May Proceed" letter for its investigational new drug application for (Z)-endoxifen in metastatic ER+/HER2- breast cancer.
The company presented this as a regulatory milestone to advance a clinical study testing (Z)-endoxifen's activity, including in tumors with resistance to other endocrine therapies and targeting the oncogenic signaling pathway PKCβ1. No clinical efficacy or safety results were reported in this announcement.
Atossa Therapeutics (Nasdaq: ATOS) was named a winner of the 2025 Clinical Trials Arena Research and Development Excellence Award in the Precision Endocrine Therapy category on December 17, 2025.
The company was honored for advancing (Z)-endoxifen, a precision-engineered SERM/D with PKCβ1 inhibition intended to provide consistent systemic exposure independent of CYP2D6 metabolism. (Z)-endoxifen is being evaluated across metastatic, neoadjuvant, adjuvant, and risk-reduction breast cancer settings, with an emerging application in Duchenne muscular dystrophy. The award recognizes scientific rigor and innovation in clinical research and development.
Atossa Therapeutics (Nasdaq: ATOS) presented four clinical updates at SABCS 2025 on (Z)-endoxifen, covering DCIS active surveillance, low-dose I-SPY2 pilot data, ESR1-mutant mechanistic results, and the Phase 2 EVANGELINE neoadjuvant trial.
Key facts: daily 10 mg (Z)-endoxifen was well tolerated with 95% of patients completing ≥75% therapy; MRI tumor volume median change was -72%; ctDNA clearance occurred in 70% of initially positive patients; EVANGELINE run-in showed 86% with Week 4 Ki-67 ≤10% supporting a 40 mg Phase 2 dose.
Atossa Therapeutics (Nasdaq: ATOS) announced on December 11, 2025 that the U.S. FDA granted Rare Pediatric Disease (RPD) designation to (Z)-Endoxifen for the treatment of Duchenne Muscular Dystrophy (DMD). RPD designation targets therapies for serious diseases affecting patients birth to 18 and can make a drug eligible for a Priority Review Voucher (PRV) upon approval. The release cites disclosed PRV sales in the last 18–24 months ranging from $100–$160 million. Company statements note enhanced FDA interaction to define a DMD clinical path, emerging preclinical data supporting (Z)-Endoxifen as a potent SERM/D, and plans to advance the program to the clinic as a potentially broader, exon-agnostic DMD approach.
Atossa Therapeutics (Nasdaq: ATOS) announced that the USPTO issued U.S. Patent No. 12,479,790 B2 on Dec 9, 2025, titled "Methods for Making and Using Endoxifen."
The patent includes 100 claims covering enteric oral formulations of highly pure (Z)-endoxifen free base, specific solid oral dosage forms, scalable manufacturing processes, and methods of use for hormone-dependent breast disorders and other estrogen-related conditions. The company says this grant adds to its existing U.S. patents and worldwide applications to support late-stage trials and potential commercialization of (Z)-endoxifen across prevention and treatment settings.
Atossa Therapeutics (Nasdaq: ATOS) completed a Type C meeting with the FDA on November 17, 2025 to review regulatory strategy for (Z)-endoxifen. The FDA provided feedback on potential expedited pathways and development options across metastatic, neoadjuvant ER+/HER2-, and breast cancer risk-reduction settings, focusing on clinical design, endpoints, and streamlined registrational approaches. Atossa said FDA input clarified routes to accelerate development and regulatory review.
Key program items: a metastatic dose-ranging study is in preparation and an IND was submitted for the metastatic program (awaiting feedback); the Phase 2 EVANGELINE neoadjuvant trial is enrolling; risk-reduction work targets low-dose effects on mammographic density. Atossa reported completing multiple trials involving nearly 800 participants and expects additional INDs in 2026.
Atossa Therapeutics (Nasdaq: ATOS) and Insilico Medicine published a joint AI-driven study in Nature Scientific Reports on Dec 2, 2025 identifying (Z)-endoxifen as a potential therapeutic candidate for glioblastoma (GBM).
The study used Insilico's PandaOmics across >900 cancer indications and multi-omic methods, ranked GBM as a top opportunity, found >1,400 shared genes reversed by endoxifen, and reported in vitro suppression of GBM cell proliferation exceeding high-dose temozolomide plus tolerable in vivo dosing. Insilico also cited 20 preclinical nominations with a 12–18 month average turnaround.
Atossa (Nasdaq: ATOS) highlighted a newly published peer‑reviewed hypothesis article and an invited scientific presentation supporting the investigational therapy (Z)-endoxifen for Duchenne muscular dystrophy (DMD) and symptomatic female carriers (D‑CAPs).
The paper maps multi‑pathway mechanisms — ER modulation, PKC‑β1 inhibition, AKT/mTOR and NF‑κB effects — and notes potential advantages over tamoxifen due to more consistent exposure. Atossa plans preclinical validation and fit‑for‑purpose clinical studies focused on safety, PK/PD, functional and cardiac endpoints; a follow‑up manuscript on utrophin modulation is under review.
Atossa Therapeutics (Nasdaq: ATOS) reported Q3 2025 results and corporate updates on Nov 12, 2025. Key items: operating expenses of $9.3M for Q3 2025 (vs $6.4M Q3 2024); prioritized IND-targeted programs for (Z)-endoxifen with a planned IND filing in Q4 2025 and an FDA Type C meeting scheduled for Nov 17, 2025. The company selected PSI as CRO for a global Phase 2 dose-ranging mBC study with enrollment post-IND and topline data expected in 2026. Hires include a new SVP R&D and a CFO to support regulatory and commercial readiness. The Israeli patent No. 304863 issued July 2, 2025; two U.S. patents face post-grant challenges.
Atossa Therapeutics (Nasdaq: ATOS) announced four abstracts featuring (Z)-endoxifen research were accepted for presentation at the 2025 San Antonio Breast Cancer Symposium (SABCS), Dec 9-12, 2025 in San Antonio, TX. The company will present four posters on Dec 11-12 covering DCIS management, a low-dose I-SPY2 endocrine pilot, ESR1 mutant activity, and a Phase 2 neoadjuvant EVANGELINE trial.
Presentations include scheduled poster sessions on Dec 11 (12:30pm–2:00pm CT) and Dec 12 (7:00am–8:30am CT and 12:30pm–2:00pm CT).
FAQ
What is the current stock price of Atossa Therapeutics (ATOS)?
What is the market cap of Atossa Therapeutics (ATOS)?
