Atossa Therapeutics Presents Data from 40mg Cohort of Phase 2 EVANGELINE Clinical Trial Showing 100% Disease Control Rate After 24-Weeks of Treatment with (Z)-Endoxifen

Rhea-AI Summary

Atossa Therapeutics (ATOS) announces positive safety and efficacy data from Phase 2 EVANGELINE trial for ER+/HER2- breast cancer treatment. The study shows significant reduction in Ki-67 levels, target lesion decreases, and promising clinical outcomes.

Positive

• Positive safety and efficacy data from Phase 2 EVANGELINE trial
• Study focuses on neoadjuvant treatment for pre-menopausal women with ER+/HER2- breast cancer
• Significant reduction in Ki-67 levels and target lesion decreases observed
• Encouraging clinical outcomes with one complete response, one partial response, and four stable disease cases
• Treatment well tolerated with manageable toxicities

Negative

• None.

Oncology Clinical Research Analyst

The Phase 2 EVANGELINE trial results from Atossa Therapeutics present a significant development in the treatment of ER+/HER2- breast cancer. The reported efficacy of (Z)-endoxifen, with a substantial reduction in Ki-67 levels and positive MRI outcomes, indicates a potential advancement in neoadjuvant therapies. Ki-67 is a important biomarker for assessing tumor proliferation; therefore, the reported decrease from 14.5% to 1.2% is noteworthy. This reduction surpasses the threshold associated with improved surgical outcomes, suggesting that (Z)-endoxifen could be a game-changer for pre-menopausal women with this cancer subtype. The lack of severe toxicities further underscores the drug's potential for a favorable risk-benefit profile. As the trial progresses, it will be essential to monitor whether these results can be replicated in larger cohorts and if the increased dosage of 80mg maintains the safety profile while enhancing antitumor efficacy.

Market Research Analyst

Atossa Therapeutics' announcement is likely to stir interest among investors, as the oncology sector closely monitors advancements in cancer treatments. The positive data from the EVANGELINE study could position Atossa as a notable player in the breast cancer treatment landscape, especially if (Z)-endoxifen continues to demonstrate a strong efficacy and safety profile in subsequent trials. Investors will be keen on the drug's progress towards FDA approval, as well as potential partnerships or licensing deals that may arise. However, it is essential to consider the competitive landscape, as other pharmaceutical companies may also be developing similar treatments. The long-term impact on Atossa's stock will depend on the company's ability to navigate the regulatory pathway and successfully bring the drug to market.

Financial Analyst

The financial implications of the EVANGELINE study's results for Atossa Therapeutics hinge on several factors. The transition from Phase 2 to Phase 3 trials and ultimately to market approval, requires substantial capital. The promising results may facilitate fundraising efforts or attract partnership opportunities. The market potential for a successful ER+/HER2- breast cancer treatment is significant, given the prevalence of this subtype. However, investors should consider the costs associated with the next phase of clinical trials, potential regulatory hurdles and the time frame for market entry. The current valuation of Atossa will likely reflect the anticipation of these factors, but actual market performance will depend on continued positive results and strategic execution by the company.

SEATTLE, April 09, 2024 (GLOBE NEWSWIRE) -- Atossa Therapeutics, Inc. (Nasdaq: ATOS) (“Atossa” or the “Company”) today announced promising safety and efficacy data from the Company’s Phase 2 EVANGELINE (Endoxifen Versus exemestANe GosEreLIn) clinical trial. The EVANGELINE study is evaluating (Z)-endoxifen as a neoadjuvant treatment for pre-menopausal women with Grade 1 or 2 Estrogen Receptor positive (ER+) / Human Epidermal Growth Factor Receptor 2 negative (HER2-) breast cancer. Atossa is a clinical stage biopharmaceutical company developing innovative medicines in areas of significant unmet medical need in oncology with a focus on breast cancer.

The data, which is being presented at the American Association for Cancer Research (AACR) Annual Meeting, is from the 40mg pharmacokinetic (PK) run-in cohort of the study. Seven women were enrolled in the cohort and treated daily for 28 days. At 28 days, six of the seven had Ki-67 levels below 10% and stayed on treatment for an additional five months. Per the study protocol, the seventh patient, whose Ki-67 decreased 19% but stayed above 10%, discontinued treatment and had surgery.

Among the six patients who were treated for a total of 24-weeks, magnetic resonance imaging (MRI) central review demonstrated target lesion decreases in all patients with one complete response (CR), one partial response (PR) and four stable disease (SD), per Response Evaluation Criteria In Solid Tumors (RECIST) criteria. The average target lesion decrease was 32% at 12 weeks and 37% at 24 weeks with all patients experiencing at least a 15% reduction in target lesion at 24-weeks.

Ki-67 for the 40mg cohort patients was reduced from an average of 14.5% at screening to 5.3% at 28 days and 1.2% at 24-weeks. This represents a reduction of 63% at 28 days and 92% at 24 weeks. Ki-67 is a cellular marker for proliferation and indicates how fast the tumor is growing. Less than 10% is considered low and associated with better surgical outcomes and a lower incidence of recurrence.

Treatment related toxicities included grade 3 headache (one patient), grade 2 amenorrhea (one patient), and grade 2 hot flashes (one patient). There were no grade 4 or 5 treatment related toxicities.

"The EVANGELINE study introduces a promising neoadjuvant approach for premenopausal women with ER+/HER2- breast cancer, exploring a potential treatment option that could improve clinical outcomes without the need for ovarian function suppression,” said Nusayba A. Bagegni, MD, Associate Professor of Medicine, Division of Oncology, Washington University School of Medicine and EVANGELINE study investigator. “The data thus far, which shows (Z)-endoxifen is beneficial and well tolerated, suggests that this treatment could potentially help address a significant unmet need in this patient population.”

“The 40mg EVANGELINE data is extremely encouraging as it shows that (Z)-endoxifen can not only stop ER+ breast cancer from growing, but it can also shrink or eliminate the tumor, as measured by MRI imaging,” said Dr. Steven Quay, Atossa’s President and Chief Executive Officer. “The depth of response at 40mg may even improve in the next phase of the study where we are now treating women with 80mg of (Z)-endoxifen daily. We expect this dose to deliver the optimal steady-state plasma concentrations required to fully target PKCβ1 inhibition and further enhance (Z)-endoxifen’s antitumor efficacy.”

About (Z)-Endoxifen
(Z)-endoxifen is the most potent Selective Estrogen Receptor Modulator (SERM) for estrogen receptor inhibition and also causes estrogen receptor degradation. It has also been shown to have efficacy in the setting of patients with tumor resistance to other hormonal treatments. In addition to its potent anti-estrogen effects, (Z)-endoxifen has been shown to target PKCβ1, a known oncogenic protein, at clinically attainable blood concentrations. Finally, (Z)-endoxifen appears to deliver similar or even greater bone agonistic effects while resulting in little or no endometrial proliferative effects compared with standard treatments, like tamoxifen.

Atossa is developing a proprietary oral formulation of (Z)-endoxifen that does not require liver metabolism to achieve therapeutic concentrations and is encapsulated to bypass the stomach, as acidic conditions in the stomach convert a significant proportion of (Z)-endoxifen to the inactive (E)-endoxifen. Atossa’s (Z)-endoxifen has been shown to be well tolerated in Phase 1 studies and in a small Phase 2 study of women with breast cancer. (Z)-endoxifen is currently being studied in four Phase 2 trials: one in healthy women with measurable breast density, one in women diagnosed with ductal carcinoma in situ, and two other studies including the EVANGELINE study in women with ER+/HER2- breast cancer. Atossa’s (Z)-endoxifen is protected by three issued U.S. patents and numerous pending patent applications.

About Premenopausal Patients with ER+ / HER2- Breast Cancer
Breast cancer is the most frequently diagnosed cancer in premenopausal women worldwide and accounts for almost half of the cancers that occur in women aged 15-49. An overwhelming majority (75%) of premenopausal breast cancer is estrogen receptor positive (ER+). Ovarian function suppression (OFS), when combined with either tamoxifen or an aromatase inhibitor, is the current standard of care for the endocrine management of stage 2 and 3 premenopausal ER+/HER2- breast cancer.

About EVANGELINE
Phase 2 EVANGELINE (Endoxifen Versus exemestANe GosEreLIn) study is investigating Atossa’s patented (Z)-endoxifen as a possible neoadjuvant treatment for pre-menopausal women with Grade 1 or 2 Estrogen Receptor positive (ER+) / Human Epidermal Growth Factor Receptor 2 negative (HER2-) breast cancer. Participants will receive neoadjuvant treatment for up to six months, followed by surgery. The study is expected to enroll approximately 175 patients at up to 25 sites across the United States.

The primary objective of the EVANGELINE study is to determine what effect treatment with (Z)-endoxifen has on tumor cell growth and how this effect compares to treatment with current standard of care, exemestane plus goserelin. Exemestane is an aromatase inhibitor designed to block the synthesis of estrogen and slow the growth of ER+ cancers. Goserelin is a medication given to block the ovaries from making estrogen, also called ovarian function suppression (OFS). In premenopausal women, OFS is associated with significant morbidity and inadequate compliance, which compromises efficacy and increases the risk of mortality.

Clinical benefit across treatment arms will be measured by change in Ki-67 level. Ki-67 is a commonly used measure of cellular proliferation and growth in breast cancer tissue. In an earlier Phase 2 study, treatment with (Z)-endoxifen resulted in a 65.1% reduction in Ki-67. This is clinically meaningful because numerous studies have shown that reducing Ki-67 improves long term survival for ER+ breast cancer patients. Patients who experience clinical benefit after four weeks of treatment with (Z)-endoxifen are eligible to stay on treatment for up to 24 weeks. Tumor burden reduction will also be assessed by MRI.

About Atossa Therapeutics
Atossa Therapeutics, Inc. is a clinical-stage biopharmaceutical company developing innovative medicines in areas of significant unmet medical need in oncology with a focus on using (Z)-endoxifen to prevent and treat breast cancer. For more information, please visit www.atossatherapeutics.com.

Contact
Eric Van Zanten
VP, Investor and Public Relations
610-529-6219
eric.vanzanten@atossainc.com

FORWARD LOOKING STATEMENTS
This press release contains certain information that may constitute forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995. We may identify these forward-looking statements by the use of words such as “expect,” “potential,” “continue,” “may,” “will,” “should,” “could,” “would,” “seek,” “intend,” “plan,” “estimate,” “anticipate,” “believe,” “future,” or other comparable words. Forward-looking statements in this press release are subject to risks and uncertainties that may cause actual results, outcomes, or the timing of actual results or outcomes, such as data related to the (Z)-endoxifen program and the potential of (Z)-endoxifen as a breast cancer prevention and treatment agent, to differ materially from those projected or anticipated, including risks and uncertainties associated with: macroeconomic conditions and increasing geopolitical instability; the expected timing of releasing data; any variation between interim and final clinical results; actions and inactions by the FDA and foreign regulatory bodies; the outcome or timing of regulatory approvals needed by Atossa, including those needed to continue our planned (Z)-endoxifen trials; our ability to satisfy regulatory requirements; our ability to remain compliant with the continued listing requirements of the Nasdaq Stock Market; our ability to successfully develop and commercialize new therapeutics; the success, costs and timing of our development activities, including our ability to successfully initiate or complete our clinical trials, including our (Z)-endoxifen trials; our anticipated rate of patient enrollment; our ability to contract with third-parties and their ability to perform adequately; our estimates on the size and characteristics of our potential markets; our ability to successfully defend litigation and other similar complaints and to establish and maintain intellectual property rights covering our products; whether we can successfully complete our clinical trial of oral (Z)-endoxifen in women with mammographic breast density and our trials of (Z)-endoxifen in women with breast cancer, and whether the studies will meet their objectives; our expectations as to future financial performance, expense levels and capital sources, including our ability to raise capital; our ability to attract and retain key personnel; our anticipated working capital needs and expectations around the sufficiency of our cash reserves; and other risks and uncertainties detailed from time to time in Atossa’s filings with the Securities and Exchange Commission, including without limitation its Annual Reports on Form 10-K and Quarterly Reports on 10-Q. Forward-looking statements are presented as of the date of this press release. Except as required by law, we do not intend to update any forward-looking statements, whether as a result of new information, future events or circumstances or otherwise.

FAQ

What is the purpose of Atossa Therapeutics' Phase 2 EVANGELINE trial?

The trial aims to evaluate (Z)-endoxifen as a neoadjuvant treatment for pre-menopausal women with Grade 1 or 2 ER+/HER2- breast cancer.

What were the key findings of the 40mg PK run-in cohort of the EVANGELINE study?

Ki-67 levels decreased below 10% in six out of seven patients treated for 28 days. Target lesion decreases were observed in all patients, with one complete response, one partial response, and four stable disease cases.

What is Ki-67 and why is it significant in breast cancer treatment?

Ki-67 is a cellular marker for proliferation, indicating tumor growth rate. Levels below 10% are associated with better surgical outcomes and lower recurrence rates.

What were the treatment-related toxicities observed in the EVANGELINE study?

Grade 3 headache, grade 2 amenorrhea, and grade 2 hot flashes were reported. No grade 4 or 5 toxicities were observed.

Who is Dr. Steven Quay and what is his role at Atossa Therapeutics?

Dr. Steven Quay is the President and CEO of Atossa Therapeutics. He mentioned the encouraging data from the 40mg EVANGELINE study.

What is the next phase of the EVANGELINE study focusing on?

The next phase of the study will involve treating women with 80mg of (Z)-endoxifen daily to enhance antitumor efficacy.

What was the average target lesion decrease observed in patients at 24 weeks?

The average target lesion decrease was 37% at 24 weeks, with all patients experiencing at least a 15% reduction in target lesion size.

What were the treatment outcomes for patients in the 40mg PK run-in cohort?

Ki-67 levels reduced by 63% at 28 days and 92% at 24 weeks, indicating significant tumor growth reduction.

What did Dr. Nusayba A. Bagegni mention about the EVANGELINE study data?

Dr. Bagegni highlighted the promising neoadjuvant approach for ER+/HER2- breast cancer and the potential clinical benefits of (Z)-endoxifen.

How many patients were enrolled in the 40mg PK run-in cohort of the EVANGELINE study?

Seven women were enrolled in the cohort and treated daily for 28 days.

What is the focus of Atossa Therapeutics as a company?

Atossa is a clinical stage biopharmaceutical company developing innovative medicines with a focus on breast cancer and other areas of unmet medical need.

What was the duration of treatment for patients in the 40mg PK run-in cohort?

Patients were treated daily for 28 days, with six patients continuing treatment for an additional five months.

What were the key findings of the MRI central review in the EVANGELINE study?

MRI central review showed target lesion decreases in all patients, with one complete response, one partial response, and four stable disease cases.

What is the significance of the RECIST criteria in evaluating treatment outcomes?

RECIST criteria are used to assess tumor response to treatment, with categories like complete response, partial response, and stable disease.

What is the significance of the American Association for Cancer Research (AACR) Annual Meeting in relation to the EVANGELINE study?

The data from the study is being presented at the AACR Annual Meeting, showcasing the promising results of (Z)-endoxifen treatment.

What is the potential impact of (Z)-endoxifen treatment on ER+ breast cancer growth?

(Z)-endoxifen has shown the ability to stop ER+ breast cancer growth and shrink or eliminate tumors, as demonstrated by MRI imaging.

How does (Z)-endoxifen treatment address the unmet medical need in premenopausal women with ER+/HER2- breast cancer?

(Z)-endoxifen offers a potential treatment option without the need for ovarian function suppression, aiming to improve clinical outcomes.

What is the role of PKCβ1 inhibition in enhancing (Z)-endoxifen's antitumor efficacy?

PKCβ1 inhibition is expected to further enhance the antitumor efficacy of (Z)-endoxifen, potentially improving treatment outcomes.

What are the benefits of a neoadjuvant approach in treating ER+/HER2- breast cancer?

Neoadjuvant treatment may lead to improved clinical outcomes by shrinking or eliminating tumors before surgery, potentially reducing the need for extensive procedures.

How does the EVANGELINE study contribute to addressing the unmet medical need in breast cancer treatment?

The study introduces a promising neoadjuvant approach for premenopausal women with ER+/HER2- breast cancer, offering potential clinical benefits.

What are the implications of the Ki-67 levels in the EVANGELINE study?

The significant reduction in Ki-67 levels indicates a decrease in tumor proliferation, which is crucial for improving surgical outcomes and reducing recurrence rates.

What are the expectations for the next phase of the EVANGELINE study with 80mg of (Z)-endoxifen?

The higher dose of (Z)-endoxifen may lead to improved antitumor efficacy and further reductions in tumor size, building on the positive outcomes observed in the 40mg cohort.