Last updated
Revenue
R&D Expenses
Operating CF
Total Assets
Total Liabilities
Equity
Shares Out.
D/E Ratio
Dilution Watch
Financials
52W LOW $1.7052W HIGH $19.35
Volume
101.01 K
Value Traded
164.05 K
Short % Float
7.75%
+3.42%Week
+0.83%1 Month
+2.11%3 Month
-51.01%6 Month
-89.86%5 Year
-99.96%All Time
Cash Data
- Monthly Burn
- Burn Trend
- Dilution Risk
- SEC Filing
Key Stats
Market Cap
24.15 M
EPS (TTM)
-3.78
P/E Ratio
-
Ent. Value
-1.94 M
Total Shares
9.98 M
Float Shares
9.83 M
Insiders
1.52%
Institutions
13.48%
Upcoming Catalysts
FDA decisions, readouts and PDUFA dates · scored by probability of approval
PoA blends historical approval base rates, trial design score and FDA review track record.
ATOS Catalyst Timeline
Dated clinical, regulatory and corporate events for Atossa Therapeutics, Inc.
Catalyst Timeline
Dated clinical, regulatory & corporate events for Atossa Therapeutics, Inc.
628Total events
7Upcoming
90Tier-1 (high impact)
2014 to 2036Coverage
Upcoming catalysts 2
Event history 50
▲Preclinical PoCPreclinical
Publication of preclinical study of novel (Z)-endoxifen-related compounds in npj Breast Cancer
ER-positive breast cancersource ↗
▲PublicationPresentation
Publication of novel (Z)-endoxifen-related compounds in npj Breast Cancer
ER-positive breast cancersource ↗
●Poster PresentationendoxifenPresentation
Poster presentation of (Z)-Endoxifen preclinical data in MAS-PPP at AACR Special Conference on Rare Cancers
McCune-Albright Syndrome-associated Peripheral Precocious Puberty (MAS-PPP)source ↗
▲Enrollment CompleteendoxifenTrial
Enrollment completed in EVANGELINE Phase 2 study
Breast Cancersource ↗
▼Equity OfferingCorporate
Closing of registered direct offering of up to $16.5 million in gross proceeds
◆Poster PresentationendoxifenPresentation
Trial-in-progress poster for EVANGELINE Phase 2 study at ASCO 2026
ER+/HER2- breast cancersource ↗
◆Poster PresentationendoxifenPresentation
Preclinical data abstract on (Z)-endoxifen activity across ESR1 mutations accepted for ASCO 2026
ER+/HER2- breast cancersource ↗
▲PublicationendoxifenPresentation
Manuscript on (Z)-endoxifen as utrophin modulator in DMD accepted for publication in Degenerative Neurological and Neuromuscular Disease
Duchenne Muscular Dystrophysource ↗
◆Oral PresentationendoxifenPresentation
Virtual KOL event featuring Dr. Laura Esserman discussing (Z)-endoxifen development
ER-positive breast cancersource ↗
▲Full ResultsendoxifenClinical Data
Publication of KARISMA Endoxifen Phase 2 results in JNCI showing significant MBD reduction
breast cancer risk reduction (mammographic breast density reduction)source ↗
▲Rare Pediatric DiseaseendoxifenDesignation
FDA grants Rare Pediatric Disease designation for (Z)-endoxifen for McCune-Albright Syndrome
McCune-Albright Syndromesource ↗
▲Rare Pediatric DiseaseendoxifenDesignation
FDA Rare Pediatric Disease designation for (Z)-endoxifen for McCune-Albright Syndrome
McCune-Albright Syndromesource ↗
◆Topline ReadoutendoxifenClinical Data
Preliminary data expected for combination arms with elagolix and GnRH agonist
breast cancer (neoadjuvant)source ↗
▲Rare Pediatric DiseaseendoxifenDesignation
FDA Rare Pediatric Disease designation for (Z)-endoxifen in DMD
Duchenne Muscular Dystrophy (DMD)source ↗
▲Orphan Drug DesignationendoxifenDesignation
FDA Orphan Drug designation for (Z)-endoxifen in DMD
Duchenne Muscular Dystrophy (DMD)source ↗
▲Management ChangeCorporate
Appointment of Kathy Puyana Theall, M.D. as Medical Director - Breast Oncology
◆Oral PresentationendoxifenPresentation
Oral presentation of preclinical data on (Z)-endoxifen in DMD at MDA Clinical & Scientific Conference
Duchenne Muscular Dystrophysource ↗
●Enrollment UpdateendoxifenTrial
Enrollment nearly complete for combination therapy arms with abemaciclib and elagolix
breast cancer (neoadjuvant)source ↗
▲PRV GrantedendoxifenDesignation
PRV program reauthorized for 5 years; (Z)-endoxifen eligible for future PRV upon FDA approval
Duchenne Muscular Dystrophysource ↗
▲Orphan Drug DesignationendoxifenDesignation
FDA grants Orphan Drug Designation for (Z)-Endoxifen in Duchenne muscular dystrophy
Duchenne muscular dystrophysource ↗
▲IND ClearanceendoxifenIND
FDA issued 'Study May Proceed' letter for (Z)-Endoxifen IND in metastatic breast cancer
metastatic breast cancersource ↗
▲Orphan Drug DesignationendoxifenDesignation
FDA Orphan Drug Designation for (Z)-endoxifen for DMD
Duchenne Muscular Dystrophysource ↗
▲Rare Pediatric DiseaseendoxifenDesignation
FDA Rare Pediatric Disease designation for (Z)-endoxifen for DMD
Duchenne Muscular Dystrophysource ↗
▼Equity OfferingCorporate
Registered direct offering raising $4.5 million upfront with potential additional $12 million
▲Oral PresentationendoxifenPresentation
Won 2025 Clinical Trials Arena Research and Development Excellence Award in Precision Endocrine Therapy
breast cancer, Duchenne Muscular Dystrophysource ↗
◆Enrollment UpdateendoxifenTrial
EVANGELINE study update: expected continued enrollment and data generation
ER+/HER2- breast cancersource ↗
◆Poster PresentationendoxifenPresentation
A Randomized Phase 2 Non-Inferiority Trial of (Z)-Endoxifen + Goserelin vs Exemestane + Goserelin as Neoadjuvant Treatment for Premenopausal Women with ER+/HER2- Breast Cancer (EVANGELINE)
ER+/HER2- breast cancersource ↗
▲Rare Pediatric DiseaseendoxifenDesignation
FDA grants Rare Pediatric Disease designation for (Z)-Endoxifen for DMD
Duchenne Muscular Dystrophysource ↗
◆Poster PresentationendoxifenPresentation
Initial results from RECAST DCIS: Multicenter platform trial testing active surveillance and novel endocrine therapy agents for DCIS management
breast cancersource ↗
▲Patent GrantedendoxifenIP / Competition
USPTO issued U.S. Patent No. 12,479,790 B2 covering enteric oral formulations of (Z)-endoxifen
hormone-dependent breast disorders and other estrogen-related conditionssource ↗
●Oral PresentationendoxifenPresentation
Presented four clinical trial updates on (Z)-endoxifen at SABCS 2025
breast cancersource ↗
◆Topline ReadoutendoxifenClinical Data
Preclinical data on (Z)-endoxifen maintaining ERα antagonist function against ESR1 mutants presented at SABCS 2025
ER+/ESR1 mutant breast cancersource ↗
●IND SubmissionendoxifenIND
Submitted IND to FDA for metastatic breast cancer program
metastatic breast cancersource ↗
▲PublicationendoxifenPresentation
Publication of AI-driven study in Nature Scientific Reports identifying (Z)-endoxifen as potential therapeutic candidate for GBM
glioblastoma multiforme (GBM)source ↗
◆Type C MeetingendoxifenFDA Meeting
Completed Type C meeting with FDA to review regulatory strategy for (Z)-endoxifen
breast cancersource ↗
●PublicationendoxifenPresentation
Publication of hypothesis article on (Z)-endoxifen in DMD
Duchenne Muscular Dystrophysource ↗
●Oral PresentationendoxifenPresentation
Presentation at 2nd International Conference on Women's Health, Reproduction & Obstetrics
Duchenne carrier-associated pathologiessource ↗
●PreprintendoxifenPresentation
Submission of manuscript on utrophin modulation by (Z)-endoxifen in DMD
Duchenne Muscular Dystrophysource ↗
●Oral PresentationPresentation
Laura Esserman speaks at Early Detection Research Conference about RECAST trial
ductal carcinoma in situ (DCIS)source ↗
●Enrollment UpdateendoxifenTrial
50 patients enrolled in RECAST trial toward target of 400
ductal carcinoma in situ (DCIS)source ↗
●Protocol AmendmentendoxifenTrial
Amendment to EVANGELINE study design reducing patient total to 40-65, single-arm open-label
ER+/HER2- breast cancersource ↗
Past FDA Catalysts and PDUFA Decisions
How ATOS actually traded into and out of each decision
| Date | Drug | Catalyst | Stage | Reaction | Event Move % | Best Trade % |
|---|---|---|---|---|---|---|
| 2024-12-31 | Z-endoxifen | Phase 2 data readout | Phase 2 |
Reaction: 30 trading days around the event · Event Move: close to close on decision day · Best Trade: peak run-up from entry 10 days before the decision
Drug Pipeline Intelligence
D30 / 100
Pipeline Score
$11M
Pipeline Value
Overvalued
Valuation Signal
2
Drugs Scored
0.5x
rNPV / MCap
Top 68%
Micro Cap(rank 448 of 658)
Percentile Rank
Atossa Therapeutics, Inc. faces pipeline headwinds (30/100), with $736M risk-adjusted pipeline value, led by endoxifen in Breast Neoplasms (Phase 2).
| Drug | Indication | Phase | PTRS | rNPV | Status | Enroll | Velocity | Design | Est. Completion | ML Signal | Last Change |
|---|---|---|---|---|---|---|---|---|---|---|---|
| Z-Endoxifen Small moleculeCompletedNCT05068388 | Breast Density | Phase 2 | COMPLETED | 240 | Mar 12, 2026 |
Clinical Trial Results
Readouts, endpoints and source filings for every ATOS program
| Drug Name | Indication | Phase | Date | Trial Results Summary | Title | Source |
|---|---|---|---|---|---|---|
| Endoxifen OrphanRare Pediatric | breast cancer risk reduction | Phase 2 | 2026-05-06 | 1 mg dose reduced MBD by 19.3% versus placebo (p=0.004); 2 mg dose reduced MBD by 26.5% (p<0.001)Read More | Atossa Therapeutics Announces Publication of KARISMA Endoxifen Trial Demonstrating Significant Reduction in Mammographic Breast Density in Healthy Premenopausal WomenRead More |
Inside Trades
| Insider | Side | Shares | Price | Value | Date |
|---|---|---|---|---|---|
| Steinhart Richard IDirector | Grant/Award | 10,000 10,000 held | $0.00 | 05/12/2026 |
Hedge Fund 13F Activity
Hedge Funds invested in ATOS
| Fund | % of Portfolio | Current MV | Shares Owned | Activity |
|---|---|---|---|---|
| No hedge fund reported a 13F position in ATOS for Q2 2026. | ||||
ATOS Institutional Ownership Trends
Options Data
Option Volume
Open Interest
Call OI
Put OI
Put-Call Ratio
OI 30-day avg
Today vs avg
Option Volume
Call Vol
Put Vol
Put-Call Ratio
Vol 30-day avg
Today vs avg
Option Chain Statistics
| Expiry | Call Vol | Put Vol | Vol P/C | Call OI | Put OI | OI P/C | IV Call | IV Call OI-Wtd | IV Call Vol-Wtd | IV Put | IV Put OI-Wtd | IV Put Vol-Wtd |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 2026-10-16 | ||||||||||||
Real-Time Option Chain
| Calls | Strike | Puts | ||||
|---|---|---|---|---|---|---|
| Last | Vol | OI | Last | Vol | OI | |
| No data available | ||||||
Calls vs Puts by Expiry
CallsPutsLog scale
Competitive positioning
How ATOS ranks across every disease it competes in
Competitive Position is a premium feature
See how ATOS ranks against every competitor across each disease it develops in: phase, best drug, trials and likelihood of approval.
Start free trialATOS News
ATOSAtossa Therapeutics Announces Plan to Issue Stapled CVR for Shareholders Tied to Potential Rare Pediatric Disease Priority Review Voucher
Atossa Therapeutics plans to issue contingent value rights (CVRs) to shareholders, allowing them to benefit from the potential monetization of a priority review voucher related to its rare pediatric disease programs. Each CVR will entitle holders to 25% of net proceeds from the voucher, subject to a $50 million cap. However, no product has been approved yet, and the CVRs are contingent on future developments.
Read more →ATOS▼ -6%on this newsshared move
Atossa Therapeutics CEO Dr. Steven Quay to Participate in ARDD 2026 Panel on Clinical Trials and Regulatory Pathways for Diseases of Aging
Atossa Therapeutics CEO Dr. Steven Quay will join a panel at the ARDD 2026 to discuss the translation of scientific evidence in aging into clinical trials and regulatory pathways. The event, taking place at Harvard University, aims to explore innovative approaches to drug development for age-related diseases. Dr. Quay emphasizes the importance of strong biological evidence in clinical trial design.
Read more →ATOSAtossa Therapeutics Reports Second Quarter 2026 Financial Results and Provides a Corporate Update
Atossa Therapeutics reported its financial results for Q2 2026, highlighting progress in developing (Z)-endoxifen for rare diseases and breast cancer. The company presented new data at major conferences, reinforcing the drug's potential. Despite a net loss of $8.5 million and increased operating expenses, Atossa secured additional funding through a registered direct offering.
Read more →ATOSAtossa Therapeutics Announces Publication of Novel (Z)-Endoxifen-Related Compounds Demonstrating Potent Anti-Cancer Activity in ER-Positive Breast Cancer
Atossa Therapeutics announced the publication of a study identifying five novel (Z)-endoxifen-related compounds that exhibit potent anti-cancer activity in estrogen receptor-positive breast cancer models. The compounds showed promising results, particularly in combination with abemaciclib, and in models with ESR1 mutations. Further evaluation of these compounds is warranted, although current findings are preclinical and do not confirm safety or efficacy in patients.
Read more →ATOSAtossa Therapeutics Announces Presentation of Mechanism-Driven (Z)-Endoxifen Data in McCune-Albright Syndrome at AACR Special Conference on Rare Cancers
Atossa Therapeutics presented data on (Z)-endoxifen at the AACR Special Conference, showcasing its dual mechanism of action for treating McCune-Albright Syndrome. The findings suggest that (Z)-endoxifen could effectively modulate estrogen receptor signaling and associated pathways, addressing significant therapeutic gaps in managing estrogen-driven conditions. This research supports further exploration of (Z)-endoxifen as a targeted treatment option.
Read more →ATOSAtossa Therapeutics Announces Closing of Registered Direct Offering of up to $16.5 Million in Gross Proceeds
Atossa Therapeutics has successfully closed a registered direct offering, raising $4.5 million in gross proceeds. The offering includes Series A and Series B warrants, which could potentially yield an additional $12 million if fully exercised. The funds will be allocated towards clinical development and general corporate purposes. The company emphasizes that there are no guarantees regarding the exercise of the warrants.
Read more →ATOS▼ -41.3%on this newsshared move
Atossa Therapeutics Announces Registered Direct Offering of up to $16.5 Million in Gross Proceeds
Atossa Therapeutics has announced a registered direct offering to raise up to $16.5 million, consisting of $4.5 million upfront and potential additional proceeds from warrants. The offering is aimed at funding clinical development and general corporate purposes. The closing is expected around June 12, 2026, pending customary conditions.
Read more →ATOSAtossa Therapeutics Announces ASCO 2026 Abstracts Highlighting (Z)-Endoxifen Activity Across ESR1 Mutations and Ongoing EVANGELINE Phase 2 Trial
Atossa Therapeutics announced the acceptance of two abstracts for presentation at the ASCO 2026 Annual Meeting, highlighting the efficacy of (Z)-endoxifen in treating ER-positive breast cancer with ESR1 mutations. Preclinical results indicated significant estrogen receptor inhibition, suggesting (Z)-endoxifen's potential role in overcoming endocrine resistance. Additionally, the ongoing EVANGELINE Phase 2 trial is evaluating its effectiveness combined with goserelin as neoadjuvant therapy for premenopausal women. This research underscores Atossa's commitment to addressing important treatment gaps in breast cancer care.
Read more →ATOSAtossa Therapeutics Announces Acceptance of Manuscript Highlighting Utrophin-Modulation Potential of (Z)-Endoxifen in Duchenne Muscular Dystrophy
Atossa Therapeutics announced the acceptance of a manuscript detailing the potential of (Z)-endoxifen to modulate utrophin pathways in Duchenne Muscular Dystrophy (DMD). The review highlights how (Z)-endoxifen may support muscle stabilization and repair. The company plans further preclinical evaluations and biomarker development to explore its therapeutic potential.
Read more →ATOSAtossa Therapeutics to Host Virtual KOL Event Featuring Dr. Laura Esserman to Discuss Development of (Z)-Endoxifen in ER-Positive Breast Cancer
Atossa Therapeutics will host a virtual event featuring Dr. Laura Esserman to discuss the development of (Z)-endoxifen for ER-positive breast cancer. The event will cover recent clinical data, including the I-SPY2 study and biomarker findings. Dr. Esserman, a leader in breast cancer research, will provide insights into the therapy's potential as an endocrine treatment across various settings.
Read more →ATOSAtossa Therapeutics Reports First Quarter 2026 Financial Results and Provides a Corporate Update
Atossa Therapeutics reported its financial results for Q1 2026, highlighting progress in the development of (Z)-endoxifen for breast cancer and rare diseases. The company received FDA designations for its drug in Duchenne Muscular Dystrophy and McCune-Albright Syndrome. Despite a strong balance sheet, operating expenses and net losses have increased compared to the previous year.
Read more →ATOSAtossa Therapeutics Announces Publication of KARISMA Endoxifen Trial Demonstrating Significant Reduction in Mammographic Breast Density in Healthy Premenopausal Women
Atossa Therapeutics announced the publication of the KARISMA Endoxifen trial results, which demonstrated that low-dose Endoxifen significantly reduces mammographic breast density in healthy premenopausal women. The Phase 2 study showed reductions comparable to tamoxifen, with a favorable tolerability profile. The findings suggest Endoxifen could be a promising option for breast cancer risk reduction.
Read more →ATOS▲ +9.9%on this newsshared move
Atossa Therapeutics Receives FDA Rare Pediatric Disease Designation for (Z)-Endoxifen for McCune-Albright Syndrome
Atossa Therapeutics has received FDA Rare Pediatric Disease designation for (Z)-endoxifen, aimed at treating McCune-Albright Syndrome in females. This designation not only validates the drug's potential beyond oncology but also opens up opportunities for a Priority Review Voucher upon approval. The company emphasizes its commitment to addressing the significant unmet medical needs associated with this rare pediatric disorder.
Read more →ATOS▼ -13.1%on this news
Atossa Therapeutics Reports Fourth Quarter and Year-End 2025 Financial Results and Provides a Corporate Update
Atossa Therapeutics reported its financial results for Q4 and the year ending December 31, 2025. The company highlighted progress in its (Z)-endoxifen development and received FDA designations that may expedite its review process. Atossa is also focusing on commercialization efforts while managing increased operating expenses and decreased interest income.
Read more →ATOSAtossa Therapeutics Strengthens Clinical Leadership Team with the Addition of Two Experienced Biopharma Executives
Atossa Therapeutics has announced the addition of Kathy Puyana Theall, M.D. and Adebola Giwa, M.D. to its clinical leadership team. Dr. Theall will serve as Medical Director for Breast Oncology while Dr. Giwa will take on the role of Medical Director for Rare Diseases. Both executives bring extensive experience from their respective fields, which is expected to enhance Atossa's clinical development strategy for its lead product, (Z)-endoxifen, across various therapeutic areas. The company aims to meet key clinical and regulatory milestones with this strengthened team.
Read more →ATOS▲ +5.6%on this news
Atossa Therapeutics Presents Clinical Trial Update Highlighting (Z)-Endoxifen Research at the 2026 MDA Clinical & Scientific Conference
Atossa Therapeutics presented promising findings on (Z)-endoxifen at the MDA Clinical & Scientific Conference. The preclinical study indicates that (Z)-endoxifen may restore muscle performance and reduce damage biomarkers in dystrophic mice, suggesting its potential as a new treatment for Duchenne muscular dystrophy. The company emphasizes the need for further clinical investigation.
Read more →ATOS▼ -16%on this news
Atossa Therapeutics Issues Letter to Shareholders Highlighting 2025 Accomplishments and 2026 Outlook
Atossa Therapeutics provided a shareholder update highlighting its progress in 2025, particularly in advancing (Z)-endoxifen for breast cancer and other rare diseases. The company completed a Type C meeting with the FDA, clarifying potential expedited pathways for development. Despite pausing investment in metastatic breast cancer trials, Atossa is focusing on strengthening its intellectual property and preparing for future commercialization. The company enters 2026 with a clear regulatory roadmap and a strong financial position.
Read more →ATOSAtossa Therapeutics Maintains Strong Market Position for (Z)-Endoxifen for Duchenne Muscular Dystrophy as Congress Reauthorizes Priority Review Voucher Program
Atossa Therapeutics has reaffirmed its strong market position for (Z)-endoxifen in treating Duchenne Muscular Dystrophy (DMD) following Congress's reauthorization of the Rare Pediatric Disease Priority Review Voucher Program. This designation allows Atossa to qualify for a future PRV upon FDA approval, enhancing its development strategy. The company expresses optimism about the drug's potential as a treatment option for DMD, addressing significant unmet medical needs.
Read more →ATOSAtossa Therapeutics' Founder and CEO Steven Quay, M.D., Ph.D. Named One of The Top 50 Healthcare Technology CEOs of 2025
Atossa Therapeutics' CEO, Dr. Steven Quay, has been named one of the Top 50 Healthcare Technology CEOs of 2025. This accolade highlights his leadership in advancing innovative therapies, particularly (Z)-endoxifen, a treatment for breast cancer. Under his guidance, Atossa focuses on precision-based therapies and fostering a culture of innovation.
Read more →About Atossa Therapeutics, Inc.
Headquarters1448 NW MARKET STREET, SEATTLE, WA, 98107
Founded2008
BIOPHARMAWATCH ELITE PLUS
Trade the next ATOS catalyst before the market reprices
Every FDA decision, PoA score, 13F move and dilution flag on this page, for 1,100+ biotech tickers. From $19/mo billed annually.
Cancel anytime