Atossa Therapeutics

Name

Atossa Therapeutics

Legal name

Atossa Therapeutics, Inc.

Website

https://atossatherapeutics.com

Company type

Public

Founded year

2009

Operating status

Operating

Headcount range

11–50 employees

Ownership category

akta.pro rank

Product category

Oncology Pharmaceuticals

NAICS

Pharmaceutical Preparation Manufacturing (325412), Research and Development in Biotechnology (except Nanobiotechnology) (541714)

SIC

Pharmaceutical Preparations (2834)

akta.pro primary industry

Oncology & Hematology Pharmaceuticals (HLAIAAAC)

akta.pro secondary industry

Oncology Specialty Pharmaceuticals (HLAIACAA)

Keywords

• Selective estrogen receptor modulators
• Breast cancer therapeutics
• Clinical-stage biopharmaceuticals
• Endocrine therapy drugs
• Rare disease therapeutics

Headquarters

HQ city

Seattle

HQ country

United States

HQ region

North America

Offices1 record

Markets served

GTM type

B2B

Offering type

Hardware or Manufacturing

Cost components

Technology or R&D, Personnel, Operations, Marketing or Sales, Others

Revenue model

1. No Commercial Revenue: Atossa Therapeutics is a clinical-stage biopharmaceutical company with no current commercial products or sustainable revenue. The company is focused entirely on R&D investment to advance (Z)-endoxifen through clinical development toward regulatory approval. No revenue is generated from product sales.
2. Potential Future Product Revenue: Upon regulatory approval, the company plans to commercialize (Z)-endoxifen for breast cancer and rare disease indications. Analysts project potential positive profits of $48M in 2028 if clinical development succeeds.
3. Priority Review Voucher (PRV): FDA Rare Pediatric Disease designation for (Z)-endoxifen in DMD and McCune-Albright Syndrome qualifies the company for a Priority Review Voucher upon approval, which can be sold for approximately $100-205 million based on recent market transactions.

Pricing tiers

Go-to-market motion2 records

Distribution channels1 record

Marketing channels5 records

Core offering

Atossa Therapeutics is a clinical-stage biopharmaceutical company developing (Z)-endoxifen, a proprietary oral selective estrogen receptor modulator and degrader (SERM/SERD) formulated in an enteric capsule. The drug is being advanced through multiple Phase 2 clinical trials for breast cancer (metastatic, neoadjuvant, ductal carcinoma in situ, and breast density reduction) and rare diseases (Duchenne Muscular Dystrophy, McCune-Albright Syndrome, and potentially glioblastoma). All candidates are investigational, with no approved products or commercial revenue.

Product overview

Atossa Therapeutics is a clinical-stage biopharmaceutical company developing innovative medicines in oncology with a current focus on breast cancer. The company's primary product candidate is (Z)-endoxifen, a potent selective estrogen receptor modulator (SERM) that is nearly 100 times more potent than other SERMs. (Z)-endoxifen is being advanced across multiple clinical development programs including the EVANGELINE Phase 2 trial for neoadjuvant treatment of ER+/HER2- breast cancer, the KARISMA-Endoxifen trial for mammographic breast density reduction, the I-SPY 2 trial for neoadjuvant therapy, and the RECAST DCIS study for ductal carcinoma in situ. The company is also pursuing development for rare diseases including Duchenne Muscular Dystrophy and McCune-Albright Syndrome, having received FDA Orphan Drug Designation and Rare Pediatric Disease designation for these indications.

Differentiator

Problem solved

Functional benefit

Products and services

• (Z)-endoxifen (Z)-endoxifen is Atossa's proprietary oral selective estrogen receptor modulator (SERM) and degrader (SERD), developed to be approximately 100 times more potent than other SERMs with a potentially improved tolerability profile. It is formulated in an enteric capsule that bypasses stomach acidity, requires no liver metabolism for activation, and targets Protein Kinase C beta 1 (PKCβ1) in addition to estrogen receptor inhibition. The candidate is being advanced through multiple Phase 2 trials in breast cancer and rare diseases.

Quantifiable outcome

• 92% reduction in Ki-67 after 24 weeks with 40mg (Z)-endoxifen in EVANGELINE Phase 2 study
• +7 more outcomes

Named customers1 record

Segments4 records

Ideal customer profiles2 records

Technology focussed Yes

API detail

Has API

No

API docs

API detail

Core technology

AI maturity

App detail

AI capability2 records

Feature5 records

Partnerships

Five partnerships are on record, tiered core.

• PSI (Contract Research Organization)coreImplementation/ SI/ Consulting Partner · 12 June 2026PSI serves as the contract research organization (CRO) for Atossa's pivotal dose-ranging study for metastatic breast cancer. PSI supports clinical trial execution, site management, and data collection for the Phase 2/3 development of (Z)-endoxifen in this indication.
• Insilico MedicinecoreStrategic or Co-development Partner · 2 December 2025Joint study published in Nature Scientific Reports using AI-driven analysis to identify (Z)-endoxifen as a potential treatment for glioblastoma multiforme (GBM). Insilico Medicine applied its AI platform to screen cancer indications and validate endoxifen's efficacy against GBM cells in vitro and in vivo.
• Quantum Leap Healthcare CollaborativecoreStrategic or Co-development Partner · 6 November 2025Ongoing collaboration on multiple clinical trials: (Z)-endoxifen is being evaluated in the I-SPY 2 Endocrine Optimization Pilot Protocol (EOP), including a new study arm evaluating (Z)-endoxifen in combination with abemaciclib (VERZENIO). Also collaborating on the RECAST DCIS platform study for ductal carcinoma in situ.
• Weill Cornell MedicinecoreStrategic or Co-development Partner · 14 August 2023Research agreement to study the potential of inducing estrogen receptor (ER) expression in triple-negative breast cancer (TNBC). The goal is to determine if treating TNBC with extracellular vesicles carrying the ER will convert the tumor to ER+ and render it sensitive to treatment with SERMs including Atossa's proprietary (Z)-endoxifen.
• FD/MAS AlliancecoreStrategic or Co-development PartnerCollaboration with the FD/MAS Alliance (Fibrous Dysplasia/McCune-Albright Syndrome) patient advocacy group and clinical researchers at Children's Hospital of Philadelphia to advance clinical development for McCune-Albright Syndrome. Atossa participated in a research priorities workshop with clinicians, researchers, and patient advocates to define development pathways.

Scale indicators9 records

Recent moves7 records

Expansion highlights5 records

Direct peers

• Olema Oncology: Olema Oncology is developing palazestrant (OP-1250), an oral SERD for ER+ breast cancer, including in ESR1-mutated settings. Direct competitor to (Z)-endoxifen in the next-generation oral SERD/SERM space for endocrine-resistant breast cancer with similar target patient population and clinical-stage development profile.

Broad incumbents

• Eli Lilly: Eli Lilly is developing imlunestrant (LY3484356), a next-generation oral SERD for ER+ breast cancer. As a large-cap pharmaceutical incumbent, Lilly has substantially greater resources for Phase 3 development and commercialization, and imlunestrant competes directly in the ESR1-mutant setting that (Z)-endoxifen targets.
• AstraZeneca: AstraZeneca is developing camizestrant (AZD9833), a next-generation oral SERD for ER+ breast cancer, and has established leadership in the breast cancer space through fulvestrant (FASLODEX). Represents a well-capitalized competitor with overlapping clinical programs in endocrine-resistant breast cancer.
• Menarini Group: Menarini Group acquired Stemline Therapeutics and markets elacestrant (ORSERDU), the first FDA-approved oral SERD for ER+/HER2- breast cancer with ESR1 mutations. Direct competitor with already-approved product in the same ESR1-mutant segment that (Z)-endoxifen targets.
• Roche: Roche/Genentech markets fulvestrant (FASLODEX), the first-in-class SERD for ER+ breast cancer, and has a deep breast cancer portfolio. While fulvestrant is injectable (not oral), Roche represents the established incumbent in endocrine therapy with substantially greater resources for combination trials and label expansion.

Emerging players

• Arvinas: Arvinas is developing vepdegestrant (ARV-471) in partnership with Pfizer, an estrogen receptor-targeting PROTAC degrader for ER+ breast cancer. Represents next-generation ER-targeting approach with potential overlap in endocrine-resistant populations; clinical-stage peer with novel mechanism.
• Zentalis Pharmaceuticals: Zentalis Pharmaceuticals was developing ZN-c5, an oral SERD for ER+ breast cancer, before restructuring its oncology pipeline. Direct peer in the oral SERD clinical development space, though Zentalis has shifted strategic focus. Comparable clinical-stage small-cap profile.
• Puma Biotechnology: Puma Biotechnology markets neratinib (NERLYNX) for HER2-positive breast cancer and has explored expanded indications. Small-cap breast cancer-focused company with similar market cap profile to Atossa and comparable commercial-stage challenges in oncology.
• Radius Health: Radius Health previously developed elacestrant (now owned by Menarini) and has experience in SERD clinical development. Represents historical precedent in the oral SERD space and offers comparable small-cap biotech profile that eventually exited via acquisition.
• Veru Inc. Veru Inc. is a clinical-stage biopharmaceutical company with oncology programs in prostate and breast cancer, including enobosarm for AR+ ER+ breast cancer. Comparable small-cap profile with multiple oncology indications in development, though focused on different mechanism (SARM).

Market position

Strengths5 records

Weaknesses5 records

Competitive moat4 records

Key risks6 records

Key highlights7 records

Customer concentration

• Xx.com/atossainc
• Facebookfacebook.com/atossageneticsinc

Compliance3 records

Revenue estimate

Valuation estimate

Number of profiles

Profiles7 records

Funding overview

Funding rounds6 records

Investors2 records

Funding detail is available on the Subscription and Enterprise plan.Contact sales →

M&A

Investments

M&A and investment is available on the Subscription and Enterprise plan.Contact sales →

Frequently asked questions about Atossa Therapeutics