Atossa Therapeutics Publishes KARISMA Endoxifen Trial Results
Written by Emily J. Thompson, Senior Investment Analyst
Updated: 4 days ago
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Should l Buy ATOS?
Atossa Therapeutics announced the publication of results from the KARISMA Endoxifen trial in the Journal of the National Cancer Institute. The Phase 2 study evaluated daily oral Endoxifen and demonstrated that low-dose Endoxifen significantly reduced MBD, a key risk factor for breast cancer. The article highlighted data from a study funded by Atossa. The study evaluated placebo, 1 mg, and 2 mg Endoxifen administered daily for six months in 240 healthy premenopausal women enrolled through the Swedish national mammography screening program. Elevated MBD is an established risk factor for breast cancer and a recognized pharmacodynamic marker of response to endocrine risk-reduction therapy. In the KARISMA Endoxifen trial, both the 1 mg and 2 mg Endoxifen dose levels produced statistically significant reductions in MBD compared with placebo. The 1 mg dose reduced MBD by 19.3% vs. placebo, while the 2 mg dose reduced MBD by 26.5% vs. placebo. These reductions were comparable to those previously reported with standard-dose tamoxifen, but were achieved using direct administration of Endoxifen, the most therapeutically active metabolite of tamoxifen. Both levels demonstrated a favorable tolerability profile. Adverse events were generally vasomotor in nature, consistent with those previously reported for tamoxifen.
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Analyst Views on ATOS
Wall Street analysts forecast ATOS stock price to rise
4 Analyst Rating
4 Buy
0 Hold
0 Sell
Strong Buy
Current: 5.670
Low
7.00
Averages
18.33
High
40.00
Current: 5.670
Low
7.00
Averages
18.33
High
40.00
About ATOS
Atossa Therapeutics, Inc. is a clinical-stage biopharmaceutical company. It is engaged in developing medicines in areas of unmet medical need in oncology with a focus on women’s breast cancer and other breast conditions. Its lead drug candidate under development is oral (Z)-endoxifen, which it is developing for both the prevention and treatment of breast cancer. (Z)-endoxifen is the potent Selective Estrogen Receptor Modulator for estrogen receptor inhibition and causes estrogen receptor degradation. In addition to its potent anti-estrogen effects, (Z)-endoxifen has been shown to target PKCB1, a known oncogenic protein, at clinically attainable blood concentrations. It is developing a form of (Z)-endoxifen which is administered orally for the potential treatment of breast cancer and reduction of breast density. It has completed four Phase I clinical studies and two Phase II clinical studies with its proprietary (Z)-endoxifen (including oral and topical formulations).
About the author
Emily J. Thompson
Emily J. Thompson, a Chartered Financial Analyst (CFA) with 12 years in investment research, graduated with honors from the Wharton School. Specializing in industrial and technology stocks, she provides in-depth analysis for Intellectia’s earnings and market brief reports.
Atossa Therapeutics Reports Q1 2026 Financial Results and Updates
- Significant R&D Progress: Atossa Therapeutics advanced its (Z)-endoxifen clinical development in Q1 2026, particularly for breast cancer and rare diseases like Duchenne Muscular Dystrophy and McCune-Albright Syndrome, securing FDA Orphan Drug and Rare Pediatric Disease designations, highlighting its potential in high unmet medical needs.
- Increased Operating Expenses: Total operating expenses for Q1 2026 reached $9.9 million, up $2.5 million from $7.4 million in Q1 2025, primarily driven by rising R&D and administrative costs, reflecting the company's ongoing investment in product development.
- R&D Expense Breakdown: Within R&D expenses, clinical and pre-clinical trial costs amounted to $3.718 million, a 35% increase from the previous year, indicating a significant commitment to new drug development, although overall R&D expenses also experienced fluctuations in other areas.
- Strong Financial Position: As of March 31, 2026, Atossa reported cash and cash equivalents of $31.718 million, a decrease from $41.299 million at the end of 2025, yet the company maintains a solid financial foundation to support future strategic plans and enhance shareholder value.
See More
Atossa Therapeutics Q1 Financial Results
- Loss per Share: Atossa Therapeutics reported a GAAP EPS of -$1.11 for Q1 2026, indicating ongoing challenges in profitability that could undermine investor confidence.
- Increased Operating Expenses: The total operating expenses for the three months ended March 31, 2026, reached $9.9 million, up $2.5 million from $7.4 million in the same period of 2025, reflecting rising costs that may impact future financial flexibility.
- Reasons for Expense Growth: The increase in operating expenses is primarily attributed to higher spending on research and marketing, suggesting that Atossa is preparing for future product launches and market expansion, but may exert pressure on cash flow in the short term.
- Financial Health Risks: The ongoing losses and rising operating expenses could lead to greater pressure on Atossa regarding financing and investor trust, potentially affecting its long-term strategic development and market competitiveness.
See More
Atossa Announces KARISMA Trial Results for Endoxifen in Breast Cancer Prevention
- Clinical Trial Results: Atossa Therapeutics published results from the KARISMA Endoxifen trial in the Journal of the National Cancer Institute, demonstrating that low-dose Endoxifen significantly reduced mammographic density (MBD), a key risk factor for breast cancer, with a 19.3% reduction at 1 mg and 26.5% at 2 mg, providing a new therapeutic option for future breast cancer risk reduction.
- Safety and Tolerability: The trial showed that the 1 mg dose of Endoxifen had a similar tolerability profile to placebo, with only 5 adverse events in the 1 mg group compared to 11 in the 2 mg group, indicating the potential for long-term use of low-dose Endoxifen and improved patient acceptance.
- Dose Selection Insights: The study revealed that significant MBD reduction occurred at plasma concentrations of 3-4 ng/mL, with more prominent adverse effects at higher concentrations, providing crucial insights for future prevention studies and supporting the 1 mg dose as the preferred candidate.
- Strategic Implications: Atossa believes these results strengthen the rationale for advancing Endoxifen as a potential MBD reduction therapy, particularly for women with elevated MBD who may be hesitant to use current options, signaling new opportunities in the breast cancer prevention landscape.
See More
Atossa Reports Positive Results from Endoxifen Clinical Trial for Breast Cancer Risk Reduction
- Clinical Trial Results: Atossa Therapeutics' KARISMA Endoxifen trial demonstrated that both 1 mg and 2 mg doses significantly reduced mammographic breast density over six months, with reductions of 19.3% and 26.5% respectively, providing strong support for future breast cancer risk reduction strategies.
- Safety and Tolerability: The 1 mg Endoxifen dose exhibited a tolerability profile similar to placebo, with low adverse event rates, indicating its potential value in breast cancer prevention, particularly for women hesitant about existing treatment options.
- Dose Selection Insights: The study revealed that meaningful reductions in breast density occurred at low Endoxifen plasma concentrations of 3-4 ng/mL, while higher concentrations were associated with increased vasomotor symptoms, supporting the 1 mg dose as the preferred candidate for future studies.
- Strategic Implications: Atossa believes these results strengthen the rationale for advancing Endoxifen as a potential therapy for reducing mammographic density, particularly for women with elevated density or other risk factors, potentially transforming current breast cancer prevention paradigms.
See More
Atossa's Drug Receives Rare Pediatric Disease Designation
- FDA Designation Progress: Atossa Therapeutics' (Z)-endoxifen has received Rare Pediatric Disease (RPD) designation from the FDA for treating McCune-Albright Syndrome in females, marking a significant advancement in addressing pediatric rare diseases.
- Positive Market Reaction: Following this announcement, Atossa's stock surged over 8%, reflecting investor confidence in the company's ability to meet serious medical needs, despite the stock's decline of more than 40% year-to-date.
- Potential Economic Value: Should (Z)-endoxifen gain approval through a New Drug Application (NDA) or Biologics License Application (BLA), it may qualify for a Priority Review Voucher (PRV), with reported PRV sales ranging from $100 million to $205 million over the past 18 to 24 months, indicating substantial economic potential.
- CEO Outlook: CEO Steven Quay stated that (Z)-endoxifen could improve outcomes for patients with McCune-Albright Syndrome while creating non-dilutive value through the RPD program, underscoring the company's strategic focus on rare diseases.
See More
Atossa Secures Rare Pediatric Disease Designation for (Z)-endoxifen
- Rare Disease Certification: Atossa Therapeutics' (Z)-endoxifen has received FDA's Rare Pediatric Disease (RPD) designation for treating McCune-Albright Syndrome in females, marking a significant milestone in the company's development of new therapies and is expected to enhance its market competitiveness.
- Priority Review Voucher Potential: Upon approval, (Z)-endoxifen will be eligible for a Priority Review Voucher (PRV), which has seen sales ranging from $100 million to $205 million in the past 18-24 months, potentially providing non-dilutive value to the company.
- Clinical Need Fulfillment: McCune-Albright Syndrome is a serious pediatric endocrine disorder that particularly affects young girls, and (Z)-endoxifen has the potential to improve treatment outcomes for patients, addressing the urgent demand for effective therapeutic options in the market.
- Enhanced R&D Collaboration: Atossa's participation in the FD/MAS Alliance Research Priorities Workshop underscores its commitment to collaborating with the clinical and patient community, aiming to accelerate the development of new therapies and further advance the clinical progress of (Z)-endoxifen.
See More
Atossa Therapeutics Reports Q1 2026 Financial Results and Updates
- Significant R&D Progress: Atossa Therapeutics advanced its (Z)-endoxifen clinical development in Q1 2026, particularly for breast cancer and rare diseases like Duchenne Muscular Dystrophy and McCune-Albright Syndrome, securing FDA Orphan Drug and Rare Pediatric Disease designations, highlighting its potential in high unmet medical needs.
- Increased Operating Expenses: Total operating expenses for Q1 2026 reached $9.9 million, up $2.5 million from $7.4 million in Q1 2025, primarily driven by rising R&D and administrative costs, reflecting the company's ongoing investment in product development.
- R&D Expense Breakdown: Within R&D expenses, clinical and pre-clinical trial costs amounted to $3.718 million, a 35% increase from the previous year, indicating a significant commitment to new drug development, although overall R&D expenses also experienced fluctuations in other areas.
- Strong Financial Position: As of March 31, 2026, Atossa reported cash and cash equivalents of $31.718 million, a decrease from $41.299 million at the end of 2025, yet the company maintains a solid financial foundation to support future strategic plans and enhance shareholder value.
See More
Atossa Therapeutics Q1 Financial Results
- Loss per Share: Atossa Therapeutics reported a GAAP EPS of -$1.11 for Q1 2026, indicating ongoing challenges in profitability that could undermine investor confidence.
- Increased Operating Expenses: The total operating expenses for the three months ended March 31, 2026, reached $9.9 million, up $2.5 million from $7.4 million in the same period of 2025, reflecting rising costs that may impact future financial flexibility.
- Reasons for Expense Growth: The increase in operating expenses is primarily attributed to higher spending on research and marketing, suggesting that Atossa is preparing for future product launches and market expansion, but may exert pressure on cash flow in the short term.
- Financial Health Risks: The ongoing losses and rising operating expenses could lead to greater pressure on Atossa regarding financing and investor trust, potentially affecting its long-term strategic development and market competitiveness.
See More
Atossa Announces KARISMA Trial Results for Endoxifen in Breast Cancer Prevention
- Clinical Trial Results: Atossa Therapeutics published results from the KARISMA Endoxifen trial in the Journal of the National Cancer Institute, demonstrating that low-dose Endoxifen significantly reduced mammographic density (MBD), a key risk factor for breast cancer, with a 19.3% reduction at 1 mg and 26.5% at 2 mg, providing a new therapeutic option for future breast cancer risk reduction.
- Safety and Tolerability: The trial showed that the 1 mg dose of Endoxifen had a similar tolerability profile to placebo, with only 5 adverse events in the 1 mg group compared to 11 in the 2 mg group, indicating the potential for long-term use of low-dose Endoxifen and improved patient acceptance.
- Dose Selection Insights: The study revealed that significant MBD reduction occurred at plasma concentrations of 3-4 ng/mL, with more prominent adverse effects at higher concentrations, providing crucial insights for future prevention studies and supporting the 1 mg dose as the preferred candidate.
- Strategic Implications: Atossa believes these results strengthen the rationale for advancing Endoxifen as a potential MBD reduction therapy, particularly for women with elevated MBD who may be hesitant to use current options, signaling new opportunities in the breast cancer prevention landscape.
See More
Atossa Reports Positive Results from Endoxifen Clinical Trial for Breast Cancer Risk Reduction
- Clinical Trial Results: Atossa Therapeutics' KARISMA Endoxifen trial demonstrated that both 1 mg and 2 mg doses significantly reduced mammographic breast density over six months, with reductions of 19.3% and 26.5% respectively, providing strong support for future breast cancer risk reduction strategies.
- Safety and Tolerability: The 1 mg Endoxifen dose exhibited a tolerability profile similar to placebo, with low adverse event rates, indicating its potential value in breast cancer prevention, particularly for women hesitant about existing treatment options.
- Dose Selection Insights: The study revealed that meaningful reductions in breast density occurred at low Endoxifen plasma concentrations of 3-4 ng/mL, while higher concentrations were associated with increased vasomotor symptoms, supporting the 1 mg dose as the preferred candidate for future studies.
- Strategic Implications: Atossa believes these results strengthen the rationale for advancing Endoxifen as a potential therapy for reducing mammographic density, particularly for women with elevated density or other risk factors, potentially transforming current breast cancer prevention paradigms.
See More
Atossa's Drug Receives Rare Pediatric Disease Designation
- FDA Designation Progress: Atossa Therapeutics' (Z)-endoxifen has received Rare Pediatric Disease (RPD) designation from the FDA for treating McCune-Albright Syndrome in females, marking a significant advancement in addressing pediatric rare diseases.
- Positive Market Reaction: Following this announcement, Atossa's stock surged over 8%, reflecting investor confidence in the company's ability to meet serious medical needs, despite the stock's decline of more than 40% year-to-date.
- Potential Economic Value: Should (Z)-endoxifen gain approval through a New Drug Application (NDA) or Biologics License Application (BLA), it may qualify for a Priority Review Voucher (PRV), with reported PRV sales ranging from $100 million to $205 million over the past 18 to 24 months, indicating substantial economic potential.
- CEO Outlook: CEO Steven Quay stated that (Z)-endoxifen could improve outcomes for patients with McCune-Albright Syndrome while creating non-dilutive value through the RPD program, underscoring the company's strategic focus on rare diseases.
See More
Atossa Secures Rare Pediatric Disease Designation for (Z)-endoxifen
- Rare Disease Certification: Atossa Therapeutics' (Z)-endoxifen has received FDA's Rare Pediatric Disease (RPD) designation for treating McCune-Albright Syndrome in females, marking a significant milestone in the company's development of new therapies and is expected to enhance its market competitiveness.
- Priority Review Voucher Potential: Upon approval, (Z)-endoxifen will be eligible for a Priority Review Voucher (PRV), which has seen sales ranging from $100 million to $205 million in the past 18-24 months, potentially providing non-dilutive value to the company.
- Clinical Need Fulfillment: McCune-Albright Syndrome is a serious pediatric endocrine disorder that particularly affects young girls, and (Z)-endoxifen has the potential to improve treatment outcomes for patients, addressing the urgent demand for effective therapeutic options in the market.
- Enhanced R&D Collaboration: Atossa's participation in the FD/MAS Alliance Research Priorities Workshop underscores its commitment to collaborating with the clinical and patient community, aiming to accelerate the development of new therapies and further advance the clinical progress of (Z)-endoxifen.
See More
