ITEM 1A. RISK FACTORS

Summary of Risk Factors

Our business is subject to a number of risks and uncertainties, including risks and uncertainties that may prevent us from achieving our business objectives or may adversely affect our business, clinical and commercialization activities, the manufacturing of our product candidates, intellectual property, third party relationships, competitive environment, product and environmental liabilities, our ability to continue as a going concern and our common stock. Purchasing shares of common stock is an investment in our securities and involves a high degree of risk and uncertainty. You should carefully consider the following information about these risks and uncertainties, together with the other information contained in this Annual Report on Form 10-K for the year ended December 31, 2025, before purchasing our securities. If any of the following risks and uncertainties actually occur, our business, financial condition and results of operations may suffer. In that case, the market price of our common stock could decline, and you may lose part or all of your investment in our Company. These risks and uncertainties are discussed more fully below and include, but are not limited to, risks related to:

Risks Related to our Business

•

We have a history of operating losses and expect to continue to incur losses in the future.

•

We have not established sources of ongoing revenue to cover operating costs and allow us to continue as a going concern.

•

We will need to raise substantial additional capital in the future to fund our operations and we may be unable to raise such funds when needed and on acceptable terms.

•

We may expend our capital resources in ways that you do not agree or that do not produce stockholder value.

•

Any products we may develop may never achieve significant commercial market acceptance.

•

We may be unable to establish sales, marketing and commercial supply capabilities.

•

The loss of the services of our Chief Executive Officer could adversely affect our business.

•

Our acquisitions of, collaborations with, licenses with and investments in, other businesses may not yield expected benefits.

•

We may experience difficulty in locating, attracting and retaining experienced and qualified personnel, which could adversely affect our business.

•

Compounds and methods that appear promising in research and development may fail to reach later stages of development.

•

We may not obtain or maintain the regulatory approvals required to develop or commercialize some or all of our products.

•

Rare pediatric disease designation for any of our product candidates does not guarantee that the NDA for the product will qualify for a priority review voucher upon approval, and it does not lead to a faster development or regulatory review process, or increase the likelihood that our product candidates will receive marketing approval.

•

We may not enjoy the market exclusivity benefits of our orphan drug designations.

•

We are developing our products for patients who are severely ill, and patient deaths that occur in our clinical trials could negatively impact our business even if such deaths are not shown to be related to our drugs.

•

We are dependent on third-party service providers for a number of critical operational activities as well as for clinical trial activities.

•

We may encounter delays in our clinical trials or may not be able to conduct our trials in a timely manner.

•

Our clinical trials may fail to demonstrate adequately the efficacy and safety of our product candidates.

•

Our products and services may expose us to possible litigation and product liability claims.

•

The deployment of artificial intelligence (AI) in our or our collaborators’ product candidates could adversely affect our business, reputation or financial results.

•

Business disruptions, including natural disasters, severe weather, and pandemics, could seriously harm our future revenue and financial condition and increase our costs and expenses.

•

We maintain our cash at financial institutions, often in balances that exceed federally-insured limits.

•

Our ability to use net operating loss carryforwards and research tax credits to reduce future tax payments may be limited or restricted.

•

We, or our wholly-owned subsidiary, could lose our ability to operate in Australia, or our subsidiary may be unable to benefit from the past or future R&D tax rebates available under current Australian regulations

Risks Related to our Intellectual Property

•

We may not be able to protect our proprietary technology.

•

Obtaining and maintaining our patent protection depends on compliance with various procedural, document submission, fee payment and other requirements imposed by governmental patent agencies.

Table of Contents

•

Changes in U.S. patent law could diminish the value of patents in general.

•

We may not be able to protect our intellectual property rights throughout the world.

•

Our current patent portfolio may not include all patent rights needed for the full development and commercialization of our products. We cannot be sure that patent rights we may need in the future will be available for license on commercially reasonable terms, or at all.

•

Third-party claims alleging intellectual property infringement may prevent or delay our drug discovery and development efforts.

•

We cannot assure you that our current or future products will not infringe on existing or future patents.

•

We may be subject to claims that our employees, consultants or independent contractors have wrongfully used or disclosed confidential information of third parties.

•

We may be unable to adequately prevent disclosure of trade secrets and other proprietary information.

Risks Related to Our Industry

•

Legislative or regulatory reforms may make it more difficult and costly for us to obtain regulatory approval of our product candidates and to manufacture, market and distribute our products after approval is obtained.

•

Disruptions at the FDA and other government agencies could negatively affect the review of our regulatory submissions, which could negatively impact our business.

•

Our inadvertent or unintentional failure to comply with the complex government regulations concerning patients' privacy, data subjects, and of medical records could subject us to fines and adversely affect our reputation.

•

Significant disruptions in our information technology systems or breaches of data security could adversely affect our business.

•

The failure to comply with complex federal and state laws and regulations related to submission of claims for services could result in significant monetary damages and penalties and exclusion from the Medicare and Medicaid programs.

•

We face significant competition from other biotechnology and pharmaceutical companies.

•

Our employees and third-party partners may engage in misconduct or other improper activities.

•

Our business involves risk associated with handling hazardous and other dangerous materials.

Risks Related to the Securities Markets and Investment in our Securities.

•

Our shares of common stock are listed on the Nasdaq Capital Market, but we cannot guarantee that we will be able to maintain compliance with the continued listing standards or satisfy the continued listing standards going forward.

•

The sale of a substantial number of shares of our common stock into the market may cause substantial dilution.

•

The trading price of our common stock has been and is likely to continue to be volatile.

•

We have never paid dividends and we do not anticipate paying dividends in the future.

•

The ownership of our common stock may become concentrated among a small number of stockholders.

•

We may be unable to implement and maintain effective internal control over financial reporting.

•

The requirements of being a public company may strain our resources, result in litigation, and divert management's attention.

•

The anti-takeover provisions in our governing documents and Delaware law could delay or prevent a change in control which could reduce the market price of our common stock.

In evaluating our business, you should carefully consider the following discussion of material risks, events and uncertainties that make an investment in us speculative or risky in addition to the other information included in this Annual Report. A manifestation of any of the following risks and uncertainties could, in circumstances we may or may not be able to accurately predict, materially and adversely affect our business and operations, growth, reputation, prospects, operating and financial results, financial condition, cash flows, liquidity and stock price. Some of the factors, events and contingencies discussed below may have occurred in the past, but the disclosures below are not representations as to whether or not the factors, events or contingencies have occurred in the past, and instead reflect our beliefs and opinions as to the factors, events, or contingencies that could materially and adversely affect us in the future. References to past events are provided by way of example only and are not intended to be a complete listing or a representation as to whether or not such factors have occurred in the past. The risks and uncertainties described below are not the only ones we face. Our operations could also be affected by factors, events or uncertainties that are not presently known to us or that we currently do not consider to present significant risks to our business. Therefore, you should not consider the following risks to be a complete statement of all the potential risks or uncertainties that we face.

Table of Contents

Risks Related to our Business

We have a history of operating losses and expect to continue to incur losses in the future, and, as such, an investor cannot assess our profitability or performance based on past results.

Since December 2015, our business has primarily focused on the development of novel therapeutics for the treatment of breast cancer and other breast conditions. We have a limited operating history and have incurred net losses each year. Our net losses for the years ended December 31, 2025 and 2024 were $34.8 million and $25.5 million, respectively. We will continue to incur further losses in connection with costs for development of our programs, including ongoing and additional clinical studies.

Because of our limited operating history, particularly in the area of pharmaceutical development, our revenue and income potential is uncertain and cannot be based on prior results. Any evaluation of our business and prospects must be considered in light of these factors and the risks and uncertainties often encountered by companies in the development stage. Some of these risks and uncertainties include our ability to:

•

continue as a going concern;

•

commence, execute and obtain successful results from our clinical studies;

•

obtain regulatory approvals in the U.S. and elsewhere for our pharmaceuticals we are developing;

•

work with contract manufacturers to produce our pharmaceuticals under development in clinical and commercial quantities on acceptable terms and in accordance with required standards;

•

respond effectively to competition;

•

manage our growth in operations;

•

respond to changes in applicable government regulations and legislation;

•

access additional capital when required;

•

execute and successfully integrate strategic transactions, including potential acquisitions or investments; and

•

attract and retain key personnel.

We have not established sources of ongoing revenue to cover operating costs and allow us to continue as a going concern.

If we do not raise additional capital, we anticipate liquidity issues after the next twelve months and we may not continue as a going concern.

For the year ended December 31, 2025, we incurred a net loss of $34.8 million, and we had an accumulated deficit of $246.6 million. As of the date of filing this Annual Report, we expect that our existing resources should be sufficient to fund our planned operations for at least the next 12 months, however, additional capital resources will be needed to fund operations longer-term. We have not yet established an ongoing source of revenue sufficient to cover our operating costs and allow us to continue as a going concern. Our ability to continue as a going concern is dependent on obtaining adequate capital to fund operating losses until we become profitable. We plan to obtain additional capital resources by selling our equity securities as well as short-term borrowing from banks, stockholders or other related parties, if needed. However, we cannot assure you that we will be successful in accomplishing any of these plans and, if we are unable to obtain adequate capital on reasonable terms, if at all, we may be unable to develop and commercialize our product offerings or increase our geographic reach, and we could be forced to cease operations or substantially curtail our activities. We do not anticipate any revenue until our pharmaceutical programs are developed, including receipt of all necessary regulatory approvals, and we successfully commercialize these programs. These conditions raise substantial doubt as to our ability to continue as a going concern.

Macroeconomic factors could adversely impact our business and our ability to raise additional capital.

Our business and our ability to obtain adequate capital on reasonable terms, if at all, can be impacted by macroeconomic factors, such as high interest rates, the inflationary environment, recessionary fears, foreign exchange rate volatility, instability in financial institutions, government shutdowns, changes in monetary policy, changes in trade policies, including tariffs and other trade restrictions or the threat of such actions, and rising geopolitical instability. The United States has announced tariffs on imports from most countries, including significant tariffs on imports from Canada, Mexico and China, leading to increasing trade and political tensions. In response to tariffs, other countries have implemented retaliatory tariffs on U.S. goods. In addition, in September 2025, the United States announced plans to impose up to 100% tariffs on imported branded or patented pharmaceuticals, subject to certain exceptions (the Pharmaceutical Tariffs). There remains substantial uncertainty as to when such tariffs may go into effect, the level of such tariffs and whether such tariffs would apply to the importation of active pharmaceutical ingredients or bulk drug products that are intended for use in clinical trials and, more generally, about the duration of existing tariffs, tariff levels, implementation of announced tariffs, litigation challenging tariffs and whether additional tariffs or other retaliatory actions may be imposed, modified or suspended. For example, the U.S. Supreme Court ruled in February 2026 that certain tariffs imposed by the U.S. federal government under the

Table of Contents

International Emergency Economic Powers Act exceeded presidential authority and therefore are invalid. However, tariffs imposed under different statutes (including the Pharmaceutical Tariffs, if implemented) were not directly impacted by the decision and therefore remain in place. These actions and the related rising political tensions could negatively impact global macroeconomic conditions and the stability of global financial markets, which could have a material adverse effect on our business, financial condition and results of operations, including through increased supply chain costs.

We will need to raise substantial additional capital in the future to fund our operations and we may be unable to raise such funds when needed and on acceptable terms.

For the years ended December 31, 2025 and 2024, we incurred a net loss of $34.8 million and $25.5 million, respectively, and we had an accumulated deficit of $246.6 million since inception. As of December 31, 2025 and 2024, we had cash and cash equivalents of approximately $41.3 million and $71.1 million, respectively. Because we have no current sources of revenue, substantial doubt exists about our ability to continue as a going concern, and we expect that we will need to raise capital again in the future to continue to fund our operations. When we elect to raise additional funds or when additional funds are required, we may raise such funds through public or private equity offerings, debt financings, corporate collaboration and licensing arrangements or other financing alternatives. These financing arrangements may not be available on acceptable terms, if at all. If we are unable to raise additional capital in sufficient amounts or on terms acceptable to us, we may be prevented from developing our pharmaceutical candidates, pursuing acquisitions, and investing in other companies, including as a sponsor or investor in special purpose acquisition companies, licensing, development and commercialization efforts, and our ability to continue our operations, generate revenues, and achieve or sustain profitability may be substantially harmed.

For example, our ability to raise capital in the public capital markets, including through “at the market” offerings pursuant to our Sales Agreement with the Sales Agent, may be limited by, among other things, SEC rules and regulations impacting the eligibility of smaller companies to use Form S-3 for primary offerings of securities. Although alternative public and private transaction structures may be available, these may require additional time and cost, may impose operational restrictions on us, and may not be available on attractive terms.

If we raise additional funds by selling or issuing equity securities or equity-linked securities, including through our Sales Agreement, our stockholders will experience dilution and it may have an adverse effect on the price of our common stock. Debt financing, if available, would result in increased fixed payment obligations and may involve agreements that include covenants limiting or restricting our ability to take specific actions, such as incurring additional debt, making capital expenditures or declaring dividends. Any debt financing or additional equity, including securities convertible into or exercisable for equity securities, that we raise may contain terms, such as liquidation, conversion and other preferences, that are not favorable to us or our stockholders. If we raise additional funds through collaboration and licensing arrangements with third parties, it may be necessary for us to relinquish valuable rights to our technologies, future revenue streams or product candidates or to grant licenses on terms that may not be favorable to us. Should the financing we require to sustain our working capital needs be unavailable or prohibitively expensive when we require it, our business, operating results, financial condition and prospects could be materially and adversely affected, and we may be unable to continue our operations.

We may expend our capital resources in ways that you do not agree or that do not produce stockholder value.

We intend to use our capital resources to execute on our business plan, which may include acquiring or in-licensing programs and may also include the internal development of additional programs that may or may not be related to oncology. We may also use our capital resources to invest directly or indirectly in business opportunities in healthcare or other industries, including through purchases of equity in other companies and as a sponsor or as an equity investor in special purpose acquisition companies, and we may not be able to realize the expected business or financial benefits of these investments. For example, for the year ended December 31, 2024, we wrote down our Investment in equity securities by $1.7 million due to the impairment of our investment in Dynamic Cell Therapies, Inc. (DCT), a U.S. private company previously focused on Chimeric Antigen Receptor (CAR) T-cell therapies, which laid off all employees and ceased operations.

In addition, our business plan may evolve to require more capital resources than currently contemplated either because our existing programs progress more quickly or at a greater cost than currently anticipated or because we may add additional programs. Stockholders may not agree with the ways in which we expend our capital resources and our capital deployment activities may not lead to increases in stockholder value.

Any products we may develop may never achieve significant commercial market acceptance.

We may not succeed in achieving commercial market acceptance of any of our products. In order to gain market acceptance for the drugs under development, we will need to demonstrate to physicians and other healthcare professionals the benefits of these therapies, including the clinical and economic application for their particular practice, the efficacy and safety and potential advantages compared to alternative therapies. Many physicians and healthcare professionals may be hesitant to introduce new services or techniques into their practice for many reasons, including lack of time and resources, the learning curve associated with the adoption

Table of Contents

of such new services or techniques into already established procedures, the product’s cost, convenience and ease of administration, the then-current standard of care, the strength of marketing and distribution support and the uncertainty of the applicability or reliability of the results of a new product. In addition, the availability of full or even partial payment for our products, whether by third party payors (e.g., insurance companies), by government payors or the patients themselves, will likely heavily influence physicians’ decisions to recommend or use our products.

We may be unable to establish sales, marketing and commercial supply capabilities.

We do not currently have, nor have we ever had, commercial pharmaceutical sales and marketing capabilities. If any of our product candidates become approved, we would need to build these capabilities in order to commercialize our approved product candidates. The process of establishing commercial capabilities will be expensive and time consuming, and may not be successful. Even if we are successful in building these capabilities, we may not be successful in commercializing any of our product candidates.

The loss of the services of our Chief Executive Officer could adversely affect our business.

Our success is dependent in large part upon our ability to execute our business plan, manufacture our pharmaceutical drugs and attract and retain highly skilled professional personnel. In particular, due to the relatively early stage of our business, our future success is highly dependent on the services of Steven C. Quay, our Chairman, President, Chief Executive Officer and founder, who provides much of the necessary experience to execute our business plan.

Our acquisitions of, collaborations with, licenses with and investments in, other businesses may not yield expected benefits, and our inability to successfully integrate these transactions may negatively impact our business, financial condition, and results of operations.

We anticipate that we will make acquisitions of, collaborations with, licenses with or investments in businesses in the future. We may not realize the anticipated benefits, or any benefits, from these transactions. If we fail to properly evaluate, complete and execute acquisitions, our business may be seriously harmed and our stock price may decline. For us to realize the benefits of future transactions, we must successfully integrate the acquired businesses with ours. Some of the challenges to successful integration include:

•

unanticipated costs or liabilities resulting from our acquisitions;

•

inability to retain key employees from acquired businesses;

•

difficulties integrating acquired operations, personnel, and technologies;

•

diversion of management attention from existing business operations and strategy;

•

diversion of resources that are needed in other parts of our business;

•

potential write-offs of acquired assets;

•

inability to maintain relationship partners of the acquired business;

•

potential financial and credit risks associated with the acquired business;

•

the need to implement controls, procedures, and policies at the acquired company;

•

the need to comply with additional laws and regulations applicable to the acquired business; and

•

the indirect tax of any such acquisitions.

Our failure to address these risks or other problems encountered in connection with our past or future acquisitions and other transactions have in the past and could in the future cause us to fail to realize the anticipated benefits of such acquisitions and transactions, and result in higher than expected costs, the recording of asset impairment or restructuring charges and other actions which could negatively impact our business, financial condition, results of operations and our ability to execute on our strategic plan. For example, we incurred a $1.7 million impairment charge for the year ended December 31, 2024 in connection with our investment in DCT.

We may experience difficulty in locating, attracting and retaining experienced and qualified personnel, which could adversely affect our business.

We will need to attract, retain, and motivate experienced clinical development and other personnel, particularly in the greater Seattle area as we expand our pharmaceutical development activities. Personnel with the required skills and experience may be scarce or may not be available at all in this geographic region. In addition, competition for these skilled personnel is intense and recruiting and retaining skilled employees is difficult, particularly for a development-stage company such as ours. If we are unable to attract and retain qualified personnel, our development activities may be adversely affected. Even if we are successful in identifying and attracting qualified employees, recent market changes, including the labor shortage, and high inflation have increased employee-related costs substantially. As a result, our operating expenses may continue to increase in the current market environment.

Table of Contents

Compounds and methods that appear promising in research and development may fail to reach later stages of development for a number of reasons, including, among others, that clinical trials may take longer to complete than expected or may not be completed at all, and interim, top-line or preliminary clinical trial data reports may ultimately differ from actual results once data are more fully evaluated.

Successful development of pharmaceutical products is highly uncertain and obtaining regulatory approval to market drugs is expensive, difficult, and speculative. Compounds that appear promising in research and development may fail to reach later stages of development for several reasons, including, but not limited to:

•

an unacceptable safety profile;

•

lack of efficacy;

•

delay or failure in obtaining necessary U.S. and international regulatory approvals, or the imposition of a partial or full regulatory hold on a clinical trial;

•

difficulties in formulating a compound, scaling the manufacturing process, timely attaining process validation for particular drug products, and completing manufacturing to support clinical studies;

•

pricing or reimbursement issues or other factors that may make the product uneconomical to commercialize;

•

production problems, such as the inability to obtain raw materials or supplies satisfying acceptable standards for the manufacture of our products;

•

equipment obsolescence, malfunctions or failures, product quality/contamination problems or changes in regulations requiring manufacturing modifications;

•

inefficient cost structure of a compound, finished drug, or device compared to alternative treatments;

•

obstacles resulting from proprietary rights held by others, such as patent rights for a particular compound;

•

lower than anticipated rates of patient enrollment as a result of factors, such as the number of patients with the relevant conditions, the proximity of patients to clinical testing centers, perceived cost/benefit of participating in the study, eligibility criteria for tests, patient insurance approvals of trial participation, and competition with other clinical testing programs;

•

nonclinical or clinical testing requiring significantly more time than expected resources or expertise than originally expected and inadequate financing, which could cause clinical trials to be delayed or terminated;

•

failure of clinical testing to show potential products to be safe and efficacious, and failure to demonstrate desired safety and efficacy characteristics in human clinical trials;

•

suspension of a clinical trial at any time by us, an applicable collaboration partner or a regulatory authority on the basis that the participants are being exposed to unacceptable health risks or for other reasons;

•

delays in reaching or failing to reach agreement on acceptable terms with manufacturers or prospective Contract Research Organizations (CROs) and trial sites; and

•

failure of third parties, such as CROs, academic institutions, collaborators, cooperative groups, and/or investigator sponsors, to conduct, oversee, and monitor clinical trials and results.

In addition, from time to time we expect to report interim, top-line or "preliminary" data for clinical trials, including for example the results reported in 2024 for our EVANGELINE study, a Phase 2 randomized study of (Z)-endoxifen as a neoadjuvant treatment for premenopausal women with estrogen receptor positive (ER+) / human epidermal growth factor receptor 2 negative (HER2-) breast cancer, and in 2025, for our Phase 2 Endocrine Optimization Pilot sub‐study within the I‐SPY 2 TRIAL evaluating low‐dose oral (Z)‐endoxifen as a neoadjuvant treatment in women with stage II/III ER+/HER2‐negative breast cancer. Such data are based on a preliminary analysis of then-available efficacy and safety data, and such findings and conclusions are subject to change following a more comprehensive review of the data related to the particular study or trial. Interim, top-line or preliminary data are based on important assumptions, estimations, calculations and information then available to us to the extent we have had, at the time of such reporting, an opportunity to fully and carefully evaluate such information in light of all surrounding facts, circumstances, recommendations and analyses. As a result, interim, top-line or "preliminary" results may differ from future/final results, or different conclusions or considerations may qualify such results once existing data have been more fully evaluated. In addition, third parties, including regulatory agencies, may not accept or agree with our assumptions, estimations, calculations or analyses or may interpret or weigh the importance of data differently, which could impact the value of the particular program, the ability to obtain approvals, or commercialization of the particular compound and our business generally.

If the development of our products is delayed or fails, or if top-line or preliminary clinical trial data reported differ from actual results, our development costs may increase and our ability to commercialize our products may be harmed, which could harm our business, financial condition, operating results or prospects.

We may not obtain or maintain the regulatory approvals required to develop or commercialize some or all of our products.

Table of Contents

We are subject to rigorous and extensive regulation by the FDA in the U.S. and by comparable agencies in other jurisdictions, including the Europe Medicines Agency (EMA) in the European Union (E.U.), the United Kingdom’s Medicines and Healthcare products Regulatory Agency and the Therapeutic Goods Administration (TGA) in Australia.

Our product candidates are currently in research or development, and we have not received marketing approval for our products. Our products may not be marketed in the U.S. until they have been approved by the FDA and may not be marketed in other jurisdictions until they have received approval from the appropriate foreign regulatory agencies. Each product candidate requires significant research, development and pre-clinical testing and extensive clinical investigation before submission of any regulatory application for marketing approval. As a result, the regulatory pathway for these products may be more complex and obtaining regulatory approvals may be more difficult.

Obtaining regulatory approval requires substantial time, effort and financial resources, and we may not be able to obtain approval of any of our products on a timely basis, or at all. The number, size, design, and focus of pre-clinical and clinical trials that will be required for approval by the FDA, the EMA, or any other foreign regulatory agency varies depending on the compound, the disease or condition that the products are designed to address and the regulations applicable to any particular products. Pre-clinical and clinical data can be interpreted in different ways, which could delay, limit or preclude regulatory approval. The FDA, the EMA, and other foreign regulatory agencies can delay, limit, or deny approval of a product for many reasons, including, but not limited to:

•

a product may not be shown to be safe or effective;

•

the clinical and other benefits of a product may not outweigh its safety risks;

•

clinical trial results may be negative or inconclusive, or adverse medical events may occur during a clinical trial;

•

the results of clinical trials may not meet the level of statistical significance required by regulatory agencies for approval;

•

regulatory agencies may interpret data from pre-clinical and clinical trials in different ways than we do;

•

regulatory agencies may not approve the manufacturing process or determine that the manufacturing is not in accordance with current good manufacturing practices;

•

a product may fail to comply with regulatory requirements; or

•

regulatory agencies might change their approval policies or adopt new regulations.

If our products are not approved at all or quickly enough to provide net revenues to defray our operating expenses, our business, financial condition, operating results and prospects could be harmed.

We have received Rare Pediatric Disease designation by the FDA for (Z)-Endoxifen for Duchenne Muscular Dystrophy. However, Rare Pediatric Disease designation for any of our product candidates does not guarantee that the NDA for the product will qualify for a priority review voucher upon approval, and it does not lead to a faster development or regulatory review process, or increase the likelihood that our product candidates will receive marketing approval.

Under the Rare Pediatric Disease Priority Review Voucher program, upon the approval of a qualifying NDA for the treatment of a rare pediatric disease, the sponsor of such an application would be eligible for a rare pediatric disease PRV that can be used to obtain priority review for a subsequent BLA or NDA. Currently, a rare pediatric disease PRV may be issued only if the FDA approves the BLA or NDA on or before September 30, 2029. Designation of a drug for a rare pediatric disease does not guarantee that an NDA will meet the eligibility criteria for a rare pediatric disease PRV at the time the application is approved. A rare pediatric disease PRV may only be granted if a designated drug is approved or licensed by September 30, 2029, unless Congress further extends the program. If Congress does not extend this program, we may not meet the deadline for PRVs to be granted for our current programs given the expected timeline of development. Additionally, a rare pediatric disease designation does not lead to faster development or regulatory review of the product or increase the likelihood that it will receive marketing approval.

We may not enjoy the market exclusivity benefits of our orphan drug designations.

Although we may obtain orphan designations in the treatment of certain diseases our products are intended to treat, the designation may not be applicable to any particular product we might get approved and that product may not be the first product to receive approval for that indication. Under the Orphan Drug Act, the first approved product with an orphan designation receives market exclusivity, which prohibits the FDA from approving the “same” drug for the same indication. The FDA has stated that drugs can be the “same” even when they are not identical. It is possible that another drug that the FDA considers to be the “same” as (Z)-endoxifen could be approved for the treatment of a disease that one of our orphan products is intended to treat before our product is approved, which means that we may not obtain orphan drug exclusivity and could also potentially be blocked from approval until the first product’s orphan drug exclusivity period expires or we demonstrate, if we can, that our product is superior. Further, even if we obtain orphan drug exclusivity for a product, that exclusivity may not effectively protect the product from competition because different drugs can be approved for the same condition. Even after an orphan drug is approved and granted orphan drug exclusivity, the FDA can subsequently approve the same drug for the same condition if the FDA concludes that the later drug is safer, more effective or makes a major contribution to patient care. Further, orphan drug exclusivity can be lost if the FDA later determines that the request for designation was materially defective or if the applicant is unable to assure the availability of sufficient quantities of the

Table of Contents

drug to meet the needs of patients with the same approved indication or use for which the drug was approved. Orphan Drug designation neither shortens the development time or regulatory review time of a drug nor gives the drug any advantage in the regulatory review or approval process.

We do not know if, when, or how the FDA, Congress, or future judicial challenges may change the orphan drug regulations and policies in the future, and it is uncertain how any changes might affect our business. Depending on what changes the FDA may make to its orphan drug regulations and policies, our business could be adversely impacted. In view of the overturn of the Chevron doctrine in Loper Bright Enterprises v. Raimondo, this landmark Supreme Court decision may invite various stakeholders to bring lawsuits against the FDA to challenge longstanding decisions and policies, including regulatory exclusivities, which could lead to uncertainties in the industry. Further, changes in the leadership of the FDA and other federal agencies under the Trump administration may lead to new policies and changes in the regulations and operations of the FDA, which may impact our clinical development plans.

We have enrolled patients in studies of our drug candidates who may die while enrolled in our studies. Patients in our clinical trials may also experience adverse outcomes following treatment with our drug candidates, including patient death. These adverse outcomes, even if unrelated to our drugs, could expose us to lawsuits and liabilities and could diminish our ability to obtain regulatory approval and/or achieve commercial acceptance for the related drug and our business could be materially harmed.

We are dependent on third party service providers for a number of critical operational activities including, in particular, for the manufacture and testing of our products and associated supply chain operations, as well as for clinical trial activities. Any failure or delay in these undertakings by third parties could harm our business.

Our business is dependent on the performance by third parties of their responsibilities under contractual relationships. In particular, we heavily rely on third parties for the manufacture and testing of our products. We do not have an internal analytical laboratory or manufacturing facilities to allow the testing or production of products in compliance with Good Manufacturing Practices (cGMP). As a result, we rely on third parties to supply us in a timely manner with manufactured product candidates. We may not be able to adequately manage and oversee the manufacturers we choose; they may not perform as agreed or they may terminate their agreements with us. In particular, we depend on third party manufacturers to conduct their operations in compliance with applicable requirements under current Good Laboratory Practices (GLP), cGMP, Good Clinical Practices (GCP) or similar standards imposed by the U.S. and/or applicable foreign regulatory authorities, including the FDA and EMA. Any of these regulatory authorities may take action against a contract manufacturer who violates cGMP. Failure of our manufacturers to comply with FDA, EMA or other applicable regulations may cause us to curtail or stop the manufacture of such products until we obtain regulatory compliance.

We may not be able to obtain sufficient quantities of our products if we are unable to secure manufacturers when needed, or if our designated manufacturers do not have the capacity or otherwise fail to manufacture compounds according to our schedule and specifications or fail to comply with cGMP regulations. Furthermore, in order to ultimately obtain and maintain applicable regulatory approvals, any manufacturers we utilize are required to consistently produce the respective products in commercial quantities and of specified quality or execute fill-finish services on a repeated basis and document their ability to do so, which is referred to as process validation. In order to obtain and maintain regulatory approval of a compound, the applicable regulatory authority must consider the result of the applicable process validation to be satisfactory and must otherwise approve of the manufacturing process. Even if our compound manufacturing processes obtain regulatory approval and sufficient supply is available to complete clinical trials necessary for regulatory approval, there are no guarantees we will be able to supply the quantities necessary to affect a commercial launch of the applicable drug, or once launched, to satisfy ongoing demand. Any product shortage could also impair our ability to deliver contractually required supply quantities to applicable collaborators, as well as to complete any additional planned clinical trials.

We also rely on third party service providers for certain warehousing and transportation. With regard to the distribution of our drugs, we depend on third party distributors to act in accordance with Good Distribution Practice (GDP), and the distribution process and facilities are subject to continuing regulation by applicable regulatory authorities with respect to the distribution and storage of products.

In addition, we depend on medical institutions and CROs (together with their respective agents) to conduct clinical trials and associated activities in compliance with GCP and data privacy standards such as defined under the Health Insurance Portability and Accountability Act (HIPAA), General Data Protection Regulation (GDPR) and UK GDPR, and in accordance with our timelines, expectations and requirements. We are substantially dependent on the organizations conducting our clinical trials. To the extent any such third parties are delayed in achieving or fail to meet our clinical trial enrollment expectations, fail to conduct our trials in accordance with GCP, patient and data privacy standards such as HIPAA or study protocol or otherwise take actions outside of our control or without our consent, our business may be harmed. Furthermore, we conduct clinical trials in foreign countries, subjecting us to additional risks and challenges, including, patient and data privacy standards, such as GDPR and UK GDPR and in particular, as a result of the engagement of foreign medical institutions and foreign CROs, who may be less experienced with regard to regulatory matters applicable to us and may have different standards of medical care.

Table of Contents

With regard to certain of the foregoing clinical trial operations and stages in the manufacturing and distribution chain of our compounds, we rely on vendors. In most cases we use a primary vendor and have identified, in some cases, secondary vendors. In particular, our current business structure contemplates, at least in the foreseeable future, use of a primary commercial supplier for the (Z)-endoxifen drug substance. The use of primary vendors for core operational activities, such as, manufacturing, and the resulting lack of diversification, exposes us to the risk of a material interruption in service related to these primary, outside vendors. As a result, our exposure to this concentration risk could harm our business.

In addition, our employees and personnel or our vendors or partners may use AI, including generative AI, technologies to perform their work or in their operations, and the disclosure and use of personal information in AI technologies is subject to various privacy laws and other privacy obligations. Governments have passed and are likely to pass additional laws regulating AI, controlling for data bias and anti-discrimination. Any use of this technology could result in additional compliance costs, regulatory investigations and actions, and consumer lawsuits.

We also rely on a third-party information technology vendor to oversee our information technology systems, including our mechanisms, controls, technologies, systems, and other processes designed to help prevent or mitigate data loss, theft, misuse, or other security incidents or vulnerabilities affecting our data and to help maintain a stable information technology environment. As a result, our cybersecurity systems and processes are dependent upon the performance of our information technology vendor.

Although we monitor the compliance of our third-party service providers performing the aforementioned services, we cannot be certain that such service providers will consistently comply with applicable regulatory requirements or that they will otherwise timely satisfy their obligations to us. We and our third-party service providers may be subject to inspections by FDA and other regulatory authorities. Any such failure by us or by our third party service providers to comply with applicable legal or regulatory requirements and/or any failure by us to monitor their services or to plan for and manage our short- and long-term requirements underlying such services could result in shortage of the required compound, delays in or cessation of clinical trials, failure to obtain or revocation of product approvals or authorizations, product recalls, withdrawal, administrative detention, seizure of products, suspension of an applicable wholesale distribution authorization, and/or distribution of products, operating restrictions, injunctions, suspension of licenses, other administrative or judicial sanctions (including warning or untitled letters, import alerts, civil penalties and/or criminal prosecution), and/or unanticipated related expenditures to resolve shortcomings.

Such consequences could have a significant impact on our business, financial condition, operating results, or prospects.

We may encounter delays in our clinical trials or may not be able to conduct our trials in a timely manner.

Clinical trials are expensive and subject to regulatory approvals. Potential trial delays may arise from, but are not limited to:

•

supply chain disruptions, or lack of availability or increased costs of materials for our product candidates, including as a result of changes in trade policies, including tariffs or other trade restrictions or the threat of such actions;

•

outbreaks of disease, pandemics or epidemics, which could limit access to clinical trial sites, divert healthcare resources and limit the availability of medical facilities for our clinical trials;

•

failure to obtain on a timely basis, or at all, approval from the applicable Regulatory Agencies, institutional review board or ethics committee to open a clinical study;

•

lower than anticipated patient enrollment or delays in patient enrollment, including due to the size and nature of the patient population, existing conditions, patient eligibility criteria defined in the protocol, proximity of patients to trial sites, the design of the trial, our ability to recruit clinical trial investigators with the appropriate competencies and expertise, competing clinical trials for similar or alternate therapeutic treatments, clinicians’ and patients’ perception of a lack of benefit to enroll in the study for whatever reason, our ability to obtain and maintain patient consents and patients dropping out of the trial;

•

delays in reaching agreements on acceptable terms with prospective CRO or vendors;

•

failure of CROs or other third parties to effectively and timely monitor, oversee, and maintain the clinical trials;

•

the imposition of partial or full clinical holds by FDA, or the pausing or termination of our clinical trials by institutional review boards or ethics committees;

•

complying with design protocols of any applicable special protocol assessment we receive from the FDA;

•

severe or unexpected drug-related side effects experienced by patients in clinical trials;

•

availability of materials provided by third parties necessary to manufacture our product candidates; and

•

changes in regulatory requirements, or additional regulatory requirements.

Our clinical trials may fail to demonstrate adequately the efficacy and safety of our product candidates, which would prevent or delay regulatory approval and commercialization.

Table of Contents

Even if our clinical trials are completed as planned, we cannot be certain that their results will support our product candidate claims or that the FDA or foreign authorities will agree with our conclusions. Success in pre-clinical studies and early clinical trials does not ensure that later clinical trials will be successful, and we cannot be sure that the later trials will replicate the results of prior trials and pre-clinical studies. The clinical trial process may fail to demonstrate that our product candidates are safe and effective for the proposed indicated uses. If the FDA concludes that our clinical trials have failed to demonstrate safety and effectiveness, we would not receive FDA approval to market that product candidate in the U.S. for the indications sought. In addition, it could cause us to abandon the product candidate and might delay development of other product candidates. Any delay or termination of our clinical trials would delay or preclude the filing of any submissions with the FDA and, ultimately, our ability to commercialize our product candidates and generate revenues. It is also possible that patients enrolled in clinical trials could experience adverse side effects that are not currently part of a product candidate's profile.

Our products and services may expose us to possible litigation and product liability claims.

Our business may expose us to potential product liability risks inherent in the testing, marketing, and processing personalized medical products, particularly those products and services we offered prior to shifting our focus on pharmaceutical development. Product liability risks may arise from, but are not limited to:

•

death of severely ill patients participating in our studies; and

•

adverse events related to drugs and therapies we are developing.

A successful product liability claim, or the costs and time commitment involved in defending against a product liability claim, could have a material adverse effect on our business. Regardless of the merit or outcome of a claim, it may result in decreased demand for our product candidates, reputational harm, withdrawal of clinical trial participants, investigations by regulators, withdrawal of prior governmental approvals, substantial monetary awards to patients, loss of revenue and the inability to commercialize our product candidates. Although we currently carry clinical trial insurance and product liability insurance which we believe to be reasonable, it may not be adequate to cover all liability that we may incur. An inability to renew our policies or to obtain sufficient insurance at an acceptable cost and on commercially desirable or reasonable terms, if at all, including due to a successful product liability claim, could prevent or inhibit the commercialization of our products.

The deployment of AI in our or our collaborators' product candidates could adversely affect our business, reputation or financial results.

We or our collaborators may integrate AI, including generative AI, and machine learning tools in connection with drug discovery efforts and the development of our product candidates. As a rapidly evolving technology, the use of AI is subject to numerous risks and uncertainties, including operational, technical, legal, compliance, privacy, data security, ethical, competitive and reputational risks. Machine learning and predictive analytics may produce flawed, biased, incomplete, overbroad or inaccurate results, which could negatively impact the development of our or our collaborators’ product candidates and expose us to competitive and reputational harm. Developing, testing and deploying resource-intensive AI systems, or supporting our collaborator’s development of such systems, including our sponsorship of the Phase 2 SMART study seeking to validate an AI-driven breast cancer risk assessment model, may require significant investment and increase our costs, and there is no guarantee that any such investment will lead to the discovery of new product candidates, eventual regulatory approval or commercialization of any product candidates, or acceleration of, or reduction in, costs associated with the drug discovery, development or approval timeline. Our inability, or our collaborators' inability, to successfully use AI-enabled tools in the discovery or development of product candidates, or lack of public acceptance of such products, could adversely affect our business, reputation and financial results.

Business disruptions, including natural disasters, severe weather and pandemics, could seriously harm our future revenue and financial condition and increase our costs and expenses.

Our operations are based primarily in Seattle, Washington. These operations could be subject to power shortages, telecommunications failures, water shortages, floods, earthquakes, fires and wildfires, extreme weather conditions, pandemics or epidemics and other natural or man-made disasters or business interruptions, for which we maintain customary insurance policies that we believe are appropriate. In addition, outbreaks of viruses, infectious diseases or pandemics, terrorist acts or acts of war, or geopolitical tensions, could cause damage or cause disruptions to us, our employees, facilities, contractors and collaborators, which could have a material adverse effect on our business, financial condition and results of operations. The occurrence of any of these business disruptions could seriously harm our operations and financial condition and increase our costs and expenses. Our ability to manufacture clinical supplies of our product candidates could be disrupted if our suppliers are affected by any of the above events. We may have limited recourse against third parties if the non-compliance is due to factors outside of the manufacturer’s control.

We maintain our cash at financial institutions, often in balances that exceed federally-insured limits. The failure of financial institutions could adversely affect our ability to pay our operational expenses or make other payments.

Our cash is held at banking institutions in non-interest-bearing and interest-bearing accounts in amounts that exceed the Federal Deposit Insurance Corporation (FDIC) insurance limits. If such banking institutions were to fail, we could lose all or a portion of those

Table of Contents

amounts held in excess of such insurance limitations. For example, the FDIC took control of Silicon Valley Bank on March 10, 2023. Although we did not have cash, cash equivalents or investments at SVB and the Federal Reserve subsequently announced that account holders would be made whole, the FDIC may not make all account holders whole in the event of future bank failures. In addition, even if account holders are ultimately made whole with respect to a future bank failure, account holders’ access to their accounts and assets held in their accounts may be substantially delayed. Any material loss that we may experience in the future or inability for a material time period to access our cash and cash equivalents could have an adverse effect on our ability to pay our operational expenses or make other payments, which could adversely affect our business.

Our ability to use net operating loss carryforwards and research tax credits to reduce future tax payments may be limited or restricted.

We have generated significant net operating loss carryforwards (NOLs), and research and development tax credits (R&D credits) as a result of our incurrence of losses and our conduct of research activities since inception. We generally are able to carry NOLs and R&D credits forward to reduce our tax liability in future years. However, our ability to utilize the NOLs and R&D credits is subject to the rules of Sections 382 and 383 of the Internal Revenue Code of 1986, as amended (the Code), respectively. Those sections generally restrict the use of NOLs and R&D credits after an "ownership change." An ownership change occurs if, among other things, the stockholders (or specified groups of stockholders) who own or have owned, directly or indirectly, 5% or more of a corporation’s common stock or are otherwise treated as 5% stockholders under Section 382 of the Code and the U.S. Treasury Department regulations promulgated thereunder increase their aggregate percentage ownership of that corporation’s stock by more than 50 percentage points over the lowest percentage of the stock owned by these stockholders over the applicable testing period. In the event of an ownership change, Section 382 of the Code imposes an annual limitation on the amount of taxable income a corporation may offset with NOL carry forwards and Section 383 of the Code imposes an annual limitation on the amount of tax a corporation may offset with business credit (including R&D credits) carryforwards.

We have experienced ownership changes in the past, and there can be no assurance that we will not experience ownership changes in the future. As a result, our NOLs and business credits (including R&D credits) may be subject to limitations, and we may be required to pay taxes earlier and in larger amounts than would be the case if our NOLs or R&D credits were freely usable.

If we, or our wholly-owned subsidiary, lose our ability to operate in Australia, or if our subsidiary is unable to benefit from the past or future R&D tax rebates available under current Australian regulations, our business and results of operations could be harmed.

Through our wholly-owned subsidiary in Australia, Atossa Genetics AUS Pty Ltd., we conduct certain R&D activities, including some of our clinical trials. Current Australian tax regulations provide for a R&D cash rebate on qualified R&D activities incurred in the country. The Australian R&D tax incentive program is a self-assessment program, and as such, the Australian Taxation Office (ATO) has the right to review our program and our related expenditures for a period of four years following the tax return filing date. If we are ineligible or unable to receive the anticipated cash rebate, if past rebates are determined to be ineligible upon an audit by the ATO, or if the Australian government significantly reduces or eliminates the rebate, our business and results of operations would be adversely affected.

Based on our evaluation of the ATO's taxpayer alert published in the fourth quarter of 2023, we believe that it is no longer reasonably assured that our full tax position would be sustained under an audit. Accordingly, we recorded a change in estimate that represents our estimate of the amount (inclusive of potential penalties) that no longer meets the reasonably assured threshold. We recorded an estimated accrued current liability of $1.1 million and $1.5 million in our Consolidated Balance Sheets as of December 31, 2025 and December 31, 2024, respectively. We may in the future be required to record additional changes in estimates, which could further increase our expenses and adversely affect our business and results of operations.

Additionally, due to the geographic distance from our headquarters, we may not be able to successfully monitor or conduct our clinical trials and R&D activities in Australia and develop or commercialize our drug candidates. We can provide no assurance that the results of any clinical trials that we conduct in Australia will be accepted by the FDA or other foreign authority. Furthermore, if we lose our ability to operate our subsidiary in Australia, our business and results of operations may be adversely affected.

Risks Related to our Intellectual Property

If we are not able to protect our proprietary technology, others could compete against us more directly, which would harm our business.

Our commercial success will depend, in part, on our ability to obtain additional patents and licenses and to protect our existing patent position, both in the U.S. and in other countries, for therapeutics and related technologies, processes, methods, compositions, and other inventions that we believe are patentable, all of which provide limited protection and may not adequately protect our rights or permit us to gain or keep any competitive advantage. As of February 2, 2026, we owned and were pursuing 141 pending provisional and non-provisional patent applications (30 U.S. patent applications and 111 international patent applications, including one allowed U.S. application and two allowed international applications) and 24 issued patents (8 U.S. patents and 16 international

Table of Contents

patents). We continue to evaluate the full range of our technologies and file new patent applications consistent with our evolving business goals.

Our ability to preserve our trade secrets, trademarks and other intellectual property rights is also important to our long-term success. Our success depends in part on obtaining patent protection for our products and processes, preserving trade secrets, patents, copyrights and trademarks, operating without infringing the proprietary rights of third parties, and acquiring licenses for technology or products. If we do not adequately protect our intellectual property, competitors may be able to use our technologies and erode or negate any competitive advantage we may have, which could harm our business and ability to establish or maintain profitability. Patents may also be issued to third parties, which could interfere with our ability to bring our therapeutics to market. As the patent landscape for products for breast disorders, including breast cancers, grows more crowded and becomes more complex we may find it more difficult to obtain patent protection for our products, including those related to (Z)-endoxifen.

The laws of some foreign countries do not protect our proprietary rights to the same extent as U.S. laws, and we may encounter significant problems in protecting our proprietary rights in these countries. Even in the U.S., the patent positions of diagnostic companies and pharmaceutical and biotechnology companies, including our patent position, are generally highly uncertain, particularly after the Supreme Court decisions Mayo Collaborative Services v.Prometheus Laboratories, 132 S. Ct. 1289 (2012), Association for Molecular Pathology v. Myriad Therapeutics, Inc., 133 S. Ct. 2107 (2013), Alice Corp. v. CLS Bank International, 134 S. Ct. 2347 (2014), and Amgen Inc. v. Sanofi, 598 U.S. 594 (2023), and the Federal Circuit Court decisions Athena Diagnostics, Inc. v. Mayo Collaborative Servs., LLC, 915 F.3d 743(Fed. Cir. 2019). Our patent positions also involve complex legal and factual questions, for which important legal principles remain unresolved. No consistent policy regarding the breadth of claims allowed in pharmaceutical and biotechnology companies’ patents has emerged to date in the U.S. Furthermore, in the biotechnology and pharmaceutical fields, courts frequently render opinions that may affect the patentability of certain inventions or discoveries, including opinions that may affect the patentability of methods for diagnostics, personalized medicine, and analysis and comparison of DNA and, therefore, any patents issued to us may be challenged and potentially invalidated or found ineligible. We will be able to protect our proprietary rights from unauthorized use by third parties only to the extent that our proprietary technologies and any future tests and products are covered by valid and enforceable patents or are effectively maintained as trade secrets. In addition, our patent applications may never issue as patents, and the claims of any issued patents may not afford meaningful protection for our products, technology or tests.

The degree of future protection for our proprietary rights is uncertain, and we cannot ensure that:

•

we or others were the first to make the inventions covered by each of our patent applications;

•

we or others were the first to file patent applications for our claimed inventions;

•

others will not independently develop similar or alternative technologies or duplicate any of our technologies;

•

any of our patent applications will result in issued patents;

•

other parties will not challenge any patents issued to us;

•

any of our patents will be valid or enforceable;

•

any patents issued to us and collaborators will provide a basis for commercially viable therapeutics, will provide us with any competitive advantages or will not be challenged by third parties; or

•

the patents of others will not have an adverse effect on our business.

If a third party files a patent application with claims to a drug or drug candidate we have discovered or developed, a derivation proceeding may be initiated regarding competing patent applications. If a derivation proceeding is initiated, we may not prevail in the derivation proceeding. If the other party prevails in the derivation proceeding, we may be precluded from commercializing our products, or may be required to seek a license. A license may not be available to us on commercially acceptable terms, if at all.

If third parties successfully challenge the validity of one or more of our patent applications, we may lose certain patent rights, even if previously granted by a patent office. For example, on August 18, 2023, Intas Pharmaceuticals Ltd. (Intas) filed a Petition for Post Grant Review with the Patent Trial and Appeal Board (PTAB) of the U.S. Patent and Trademark Office (USPTO), seeking to invalidate all claims related to one of our issued patents (U.S. Patent No. 11,572,334) titled “Methods for Making and Using Endoxifen”, and on January 29, 2025, the PTAB issued a final written decision finding all claims of U.S. Patent No. 11,572,334 were unpatentable. In addition, on April 3, 2025, Intas filed two separate petitions with the PTAB seeking to invalidate two additional patents. For more information regarding our legal proceedings, including these additional petitions, refer to Note 13 “Commitments and Contingencies” to the Consolidated Financial Statements.

Any litigation proceedings relating to our proprietary technology may result in unsuccessful outcomes for us and, even if such proceedings result in successful outcomes for us, the proceedings may result in substantial costs and distract our management and other employees. Furthermore, because of the substantial amount of discovery required in connection with intellectual property litigation, there is a risk that some of our confidential information could be compromised by disclosure during this type of litigation. In addition, there could be public announcements of the results of hearings, motions or other interim proceedings or developments. If

Table of Contents

securities analysts or investors perceive these results to be negative, it could have a substantial adverse effect on the price of our common stock. Finally, we may not be able to prevent, alone or with the support of our licensors, if any, misappropriation of our trade secrets or confidential information, particularly in countries where the laws may not protect those rights as fully as in the U.S.

Obtaining and maintaining our patent protection depends on compliance with various procedural, document submission, fee payment and other requirements imposed by governmental patent agencies, and our patent protection could be reduced or eliminated for non-compliance with these requirements.

The USPTO and various foreign governmental patent agencies require compliance with a number of procedural, documentary, fee payment and other similar provisions during the patent process. Periodic maintenance fees, renewal fees, annuity fees, and various other governmental fees on any issued patents and/or applications are due to be paid to the USPTO and foreign patent agencies in several stages over the lifetime of the patents and/or applications. We have systems in place to remind us to pay these fees, and we employ outside firms and rely on our outside counsel to pay these fees. While an inadvertent lapse may sometimes be cured by payment of a late fee or by other means in accordance with the applicable rules, there are situations in which noncompliance can result in abandonment or lapse of the patent or patent application, resulting in partial or complete loss of patent rights in the relevant jurisdiction. In such an event, our competitors might be able to enter the market earlier than should otherwise have been the case, which would have a material adverse effect on our business.

Changes in U.S. patent law could diminish the value of patents in general, thereby impairing our ability to protect our products.

As is the case with other biotechnology and pharmaceutical companies, our success is heavily dependent on our intellectual property, particularly on obtaining and enforcing patents. Obtaining and enforcing patents in the biotechnology and pharmaceutical industries involve both technological and legal complexity, and is therefore costly, time-consuming and inherently uncertain. For the past several years, the U.S. has conducted proceedings involving post-issuance patent review procedures, such as inter partes review (IPR), and post-grant review (PGR) and covered business methods. These proceedings are conducted before the PTAB, of the USPTO. Each proceeding has different eligibility criteria and different patentability challenges that can be raised. In this regard, the IPR process permits any person (except a party who has been litigating the patent for more than a year) to challenge the validity of a U.S. patent on the grounds that it was anticipated or made obvious by prior art consisting of patents or printed publications. As a result, non-practicing entities associated with hedge funds, pharmaceutical companies who may be our competitors and others have challenged certain valuable pharmaceutical U.S. patents based on prior art through the IPR process. A decision in such a proceeding adverse to our interests could result in the loss of valuable patent rights, which would have a material adverse effect on our business, financial condition, results of operations and growth prospects. For example, we are currently contesting the 391 PGR Petition and the 151 IPR Petition. Refer to Note 13 “Commitments and Contingencies” to the Consolidated Financial Statements. Any potential future changes to the U.S. patent system could increase the uncertainties and costs surrounding the prosecution of our patent applications and the enforcement or defense of our issued patents, all of which could have a material adverse effect on our business, financial condition, results of operations and growth prospects. Further, recent U.S. Supreme Court rulings have narrowed the scope of patent protection available in certain circumstances and weakened the rights of patent owners in certain situations. In particular, on March 20, 2012, the U.S. Supreme Court issued the MayoCollaborative Services v. Prometheus Laboratories, Inc. decision, holding that several claims drawn to measuring drug metabolite levels from patient sampleswere not patentable subject matter. The full impact of the Mayo Collaborative Services v. Prometheus Laboratories, Inc. decision on diagnostic and certain method claims is uncertain. In addition to increasing uncertainty with regard to our ability to obtain patents in the future, this combination of events has created uncertainty with respect to the value of patents once obtained. Depending on decisions by the U.S. Congress, the federal courts, and the USPTO, the laws and regulations governing patents could change in unpredictable ways that could weaken our ability to obtain new patents or to enforce our existing patents and patents that we might obtain in the future. The standards that courts use to interpret patents are not always applied predictably or uniformly and may evolve, particularly as new technologies develop. In addition, changes to patent laws in the U.S. or other countries may be applied retroactively to affect the validity, enforceability, or term of our patent. For example, the U.S. Supreme Court has modified some legal standards applied by the USPTO in examination of U.S. patent applications, which may decrease the likelihood that we will be able to obtain patents and may increase the likelihood of challenges to patents we obtain or license.

We may not be able to protect our intellectual property rights throughout the world.

Filing, prosecuting and defending patents on our products in all countries throughout the world would be prohibitively expensive. In addition, the laws of some foreign countries do not protect intellectual property rights in the same manner and to the same extent as laws in the U.S. Consequently, we may not be able to prevent third parties from practicing our inventions in all countries outside the U.S. Competitors may use our technologies in jurisdictions where we have not obtained patent protection to develop their own products and further, may export otherwise infringing products to territories where we have patent protection, but enforcement of such patent protection is not as strong as that in the U.S. These products may compete with our products and services, and our patents or other intellectual property rights may not be effective or sufficient to prevent them from competing with our products.

Table of Contents

Many companies have encountered significant problems in protecting and defending intellectual property rights in foreign jurisdictions. The legal systems of certain countries, particularly certain developing countries, do not favor the enforcement of patents, trade secrets and other intellectual property protection, particularly those relating to biotechnology products, which could make it difficult for us to stop the infringement of our patents or marketing of competing products and services in violation of our proprietary rights generally. Proceedings to enforce our patent rights in foreign jurisdictions could result in substantial costs and divert our efforts and attention from other aspects of our business, could put our patents at risk of being invalidated or interpreted narrowly, and could provoke third parties to assert claims against us. We may not prevail in any lawsuits that we initiate, and the damages or other remedies awarded, if any, may not be commercially meaningful. Accordingly, our efforts to enforce our intellectual property rights around the world may be inadequate to obtain a significant commercial advantage from the intellectual property that we develop.

We may be unable to obtain any licenses or other rights to patents, technology, or know-how from third parties necessary to conduct our business and such licenses, if available at all, may not be available on commercially reasonable terms. Others may seek licenses from us for other technology we use or intend to use. Any failure to obtain such licenses could delay or prevent us from developing or commercializing our proposed products, which would harm our business. We may not be able to secure such a license on acceptable terms. Litigation or patent derivation proceedings may need to be brought against third parties, as discussed below, to enforce any of our patents or other proprietary rights, or to determine the scope and validity or enforceability of the proprietary rights of such third parties.

Third-party claims alleging intellectual property infringement may prevent or delay our drug discovery and development efforts.

Our commercial success depends in part on our avoiding infringement of the patents and proprietary rights of third parties, including the intellectual property rights of competitors. There is a substantial amount of litigation, both within and outside the U.S., involving patents and other intellectual property rights in the medical device and pharmaceutical fields, as well as administrative proceedings for challenging patents, including IPR, PGR, derivation, and reexamination proceedings before the USPTO or oppositions and other comparable proceedings in various foreign jurisdictions. For example, we are currently contesting the 391 PGR Petition and the 151 IPR Petition. These procedures bring uncertainty to the possibility of challenges to our patents in the future, including those patents perceived by our competitors as blocking entry into the market for their products, and the outcome of such challenges. Any such proceedings could result in revocation or amendment to our patents in such a way that they no longer cover our drug product candidates. The outcome following legal assertions of invalidity and unenforceability is unpredictable. With respect to the validity question, for example, we cannot be certain that there is no invalidating prior art and that prior art that was cited during prosecution, but not relied on by the patent examiner, will not be revisited. Numerous U.S. and foreign issued patents and pending patent applications, which are owned by third parties, exist in the fields in which we are developing our products. As the medical device, biotechnology, and pharmaceutical industries expand and more patents are issued, the risk increases that our activities related to our products may give rise to claims of infringement of the patent rights of others.

We cannot assure you that our current or future products will not infringe on existing or future patents. We may not be aware of patents that have already been issued that a third party might assert are infringed by one of our current or future products.

Third parties may assert that we are employing their proprietary technology without authorization. There may be third-party patents of which we are currently unaware with claims to materials, formulations, methods of manufacture, or methods for treatment related to the use or manufacture of our products. Because patent applications can take many years to issue and may be confidential for eighteen months or more after filing, there may be currently pending third party patent applications which may later result in issued patents that our products may infringe, or which such third parties claim are infringed by our products and services.

Parties making claims against us for infringement or misappropriation of their intellectual property rights may seek and obtain injunctive or other equitable relief, which could effectively block our ability to further develop and commercialize our products. Defense of these claims, regardless of their merit, would involve substantial expenses and would be a substantial diversion of employee resources from our business. In the event of a successful claim of infringement against us by a third party, we may have to (i) pay substantial damages, including treble damages and attorneys’ fees if we are found to have willfully infringed the third party’s patents; (ii) obtain one or more licenses from the third-party; (iii) pay royalties to the third party; or (iv) redesign any infringing products. Redesigning any infringing products may be impossible or require substantial time and monetary expenditure. Further, we cannot predict whether any required license would be available at all or whether it would be available on commercially reasonable terms. In the event that we could not obtain a license, we may be unable to further develop and commercialize our products, which could harm our business significantly. Even if we were able to obtain a license, the rights may be nonexclusive, which would give our competitors access to the same intellectual property.

Table of Contents

In addition to infringement claims against us, if third parties have prepared and filed patent applications in the U.S. that also claim technology related to our products, we may have to participate in derivation proceedings in the USPTO to determine the priority of invention. We may also become involved in similar proceedings in the patent offices in other jurisdictions regarding our intellectual property rights with respect to our products and technology.

We may use PTAB proceedings to challenge the validity of third-party intellectual property.

We actively manage risks and opportunities associated with third-party intellectual property rights. From time to time, we may identify patents or other IP held by third parties that we believe could impact our business operations, competitive position, or future commercial opportunities. In response, we may elect to challenge the validity of such third-party intellectual property by initiating proceedings before the United States Patent and Trademark Office’s Patent Trial and Appeal Board (PTAB), such as IPR or PGR.

We may pursue these PTAB challenges for strategic business reasons, including but not limited to: (i) reducing the risk of future litigation involving third-party intellectual property; (ii) improving our negotiating position in connection with licenses, partnerships, or acquisitions; (iii) removing perceived barriers to the development, commercialization, or sale of our products or services; and (iv) promoting freedom to operate in key technology areas.

Importantly, we may initiate PTAB proceedings regardless of whether the Company has been accused of infringement or whether we believe it currently infringes any such third-party intellectual property. The decision to challenge third-party intellectual property may be based on a variety of strategic considerations, including the potential impact of the intellectual property on our business, legal developments in relevant technology fields, or competitive dynamics within the industry.

There can be no assurance as to the outcome of any such PTAB proceedings. Adverse decisions in these or other proceedings could result in us having to seek licenses, modify our products or services, or cease certain activities, which could have a material adverse effect on our business, financial condition, or results of operations.

For more information regarding our legal proceedings, including these additional petitions, refer to Note 13 “Commitments and Contingencies” to the Consolidated Financial Statements.

We may be subject to claims that our employees, consultants or independent contractors have wrongfully used or disclosed confidential information of third parties.

We have received confidential and proprietary information from third parties. In addition, we employ individuals who were previously employed at other diagnostic, medical device or pharmaceutical companies. We may be subject to claims that we or our employees, consultants or independent contractors have inadvertently or otherwise improperly used or disclosed confidential information of these third parties or our employees’ former employers. Further, we may be subject to ownership disputes in the future arising, for example, from conflicting obligations of consultants or others who are involved in developing our products. We may also be subject to claims that former employees, consultants, independent contractors, collaborators or other third parties have an ownership interest in our patents or other intellectual property. Litigation may be necessary to defend against these and other claims challenging our right to and use of confidential and proprietary information. If we fail in defending any such claims, in addition to paying monetary damages, we may lose our rights therein. Such an outcome could have a material adverse effect on our business. Even if we are successful in defending against these claims, litigation could result in substantial cost and be a distraction to our management and employees.

We may be unable to adequately prevent disclosure of trade secrets and other proprietary information.

We rely on trade secret protection and confidentiality agreements to protect proprietary know-how that is not patentable or that we elect not to patent, processes for which patents are difficult to enforce, and any other elements of our discovery and development processes that involve proprietary know-how, information or technology that is not covered by patents. However, trade secrets can be difficult to protect. We require all of our employees, consultants, advisors and any third parties who have access to our proprietary know-how, information or technology, to enter into confidentiality agreements. However, we cannot be certain that all such confidentiality agreements have been duly executed, that our trade secrets and other confidential proprietary information will not be disclosed or that competitors will not otherwise gain access to our trade secrets or independently develop substantially equivalent information and techniques. Misappropriation or unauthorized disclosure of our trade secrets could impair our competitive position and may have a material adverse effect on our business. Additionally, if the steps taken to maintain our trade secrets are deemed inadequate, we may have insufficient recourse against third parties for misappropriating the trade secret.

Risks Related to Our Industry

From time to time, legislation is drafted and introduced in Congress that could significantly change the statutory provisions governing the regulatory approval, manufacture and marketing of regulated products or the reimbursement thereof. In addition, FDA

Table of Contents

regulations and guidance are often revised or reinterpreted by the FDA in ways that may significantly affect our business and our products. Any new regulations or revisions or reinterpretations of existing regulations may impose additional costs or lengthen review times of future products. In addition, FDA regulations and guidance are often revised or reinterpreted by the agency in ways that may significantly affect our business and our products. It is impossible to predict whether legislative changes will be enacted or FDA regulations, guidance or interpretations changed, and what the impact of such changes, if any, may be. Similar changes and revisions can also occur in foreign countries.

For example, the FDA may change its clearance and approval policies, adopt additional regulations or revise existing regulations, or take other actions which, may prevent or delay approval or clearance of our products under development or impact our ability to modify our currently cleared products on a timely basis. Any change in the laws or regulations that govern the clearance and approval processes relating to our current and future products could make it more difficult and costly to obtain clearance or approval for new products, or to produce, market and distribute existing products. Significant delays in receiving clearance or approval, or the failure to receive clearance or approval for our new products would have an adverse effect on our ability to expand our business.

In January 2025, an executive order entitled “Unleashing Prosperity Through Deregulation”, was issued which calls for at least 10 existing regulations to be repealed whenever an executive department or agency publicly proposes for notice and comment or otherwise promulgates a new regulation. Recent developments at the FDA include announcement of a plan to phase out animal testing for monoclonal antibodies and certain other drugs, the proposed rare disease evidence principles (RDEP) program to facilitate approval of drugs to treat rare diseases with very small patient populations with significant unmet medical need and with a known genetic defect that is the major driver of the pathophysiology, and the announcement of a new Commissioner’s National Priority Voucher program for companies supporting certain U.S. national health priorities and interests. To the extent our competitors are selected for this new voucher pilot program, or are otherwise able to participate in any of these initiatives intended to accelerate drug development and application review, and obtain approval faster, our competitive position may be harmed, which could have a material adverse effect on our business. FDA has also increased its scrutiny of foreign drug manufacturing facilities and other contractors based in China, especially with respect to the transfer of biological materials, genetic data, and other sensitive data of American patients to parties located in China. It is unclear how the industry and our clinical programs will be impacted by policies and regulations implemented under the current administration and FDA leadership, or other executive orders.

As we work to align with the FDA on development paths for combination therapies using (Z)-endoxifen in high-risk breast cancer and in other rare disease indications with significant unmet need, the scope, size, endpoints, or sequencing of required studies may change. Such changes could increase costs, extend timelines, or require modifications to our regulatory strategy. There can be no assurance that the FDA will agree with any of our proposed paths that any expedited program will be available or granted or that we will be able to successfully complete the required studies on a timely basis or at all, which could have a material adverse effect on our business.

Disruptions at the FDA and other government agencies could negatively affect the review of our regulatory submissions, which could negatively impact our business.

The ability of the FDA to review and approve regulatory submissions can be affected by a variety of factors, including statutory, regulatory and policy changes, inadequate government budget funding levels or a reduction in the FDA’s workforce and its ability to hire and retain key personnel, disruptions caused by government shutdowns, public health crises, the FDA’s ability to accept the payment of user fees, and other events that may otherwise affect the FDA’s ability to perform routine functions. There have been mass layoffs of federal employees and reorganizations since the start of the current presidential administration in January 2025, the full impact of which is unclear at this time. Such disruptions could significantly impact the ability of the FDA or other regulatory authorities to timely review and process our regulatory submissions, which could have a material adverse effect on our business. In addition, the presidential administration has made and is expected to continue to make changes in the leadership of various U.S. federal regulatory agencies and changes to U.S. federal government policy that have led to, in some cases, legal challenges and uncertainty around the funding, functioning and policy priorities of the U.S. federal regulatory agencies, including the FDA.

We are unable to predict the extent to which the presidential administration may impose or seek to impose leadership or policy changes at the FDA or changes to rules and policies impacting our business and operations. It is unclear how these executive actions or other potential actions by the federal government will impact the FDA or other regulatory authorities that oversee our business. Government proposals to reduce or eliminate budgetary deficits may include reduced allocations to the FDA and other related government agencies. These budgetary pressures may reduce the FDA’s ability to perform its responsibilities, which could result in delays in our clinical trial timelines. If a significant reduction in the FDA’s workforce occurs, the FDA’s budget is significantly reduced or the current government shutdown is prolonged, it could significantly impact the ability of the FDA to timely review and process our regulatory submissions or take other actions critical to the development or approval of our product candidates, which could have a material adverse effect on our business.

Our inadvertent or unintentional failure to comply with the complex government regulations concerning patients' privacy, other data subjects, and of medical records could subject us to fines and adversely affect our reputation.

Table of Contents

Federal privacy regulations, among other things, restrict our ability to use or disclose protected health information, including patient-identifiable laboratory data, without written patient authorization, for purposes other than payment, treatment, or healthcare operations as defined under HIPAA, except as otherwise permitted for various public policy purposes and other authorized uses under privacy regulations. Applicable privacy regulations provide for significant fines and other penalties for the wrongful use or disclosure of protected health information, including potential civil and criminal fines and penalties.

We seek to implement policies and practices designed to support compliance with applicable privacy regulations. However, the documentation and process requirements of applicable privacy regulations are complex, evolving, and subject to interpretation. Failure to comply with applicable privacy regulations could subject us to sanctions or penalties, loss of business, and negative publicity. State privacy laws may also restrict our ability to use or process personal information (including information not covered by HIPAA), and require us to adhere to additional obligations and honor additional data rights.

The HIPAA Privacy Rule establishes a “floor” of minimum protection for patients' medical information and does not supersede state privacy laws that are more stringent. State health information privacy laws, such as California’s Confidentiality of Medical Information Act and Washington’s My Health My Data Act, govern the privacy and security of health-related information and may apply even when HIPAA does not and impose additional or different requirements. Therefore, we may be required to comply with both HIPAA and state privacy laws, which vary from state to state, impose a range of obligations, and in some cases are more restrictive than HIPAA. The failure to comply with applicable privacy laws could subject us to regulatory actions, including significant fines or penalties, private actions by patients, adverse publicity and loss of business. In addition, federal and state laws and judicial decisions provide individuals with various rights for violating the privacy of their medical information by healthcare providers such as us.

In addition to HIPAA, failing to take appropriate steps to protect consumers’ personal information may result in the Federal Trade Commission (FTC) bringing a claim that a company has engaged in unfair or deceptive acts or practices in or affecting commerce, in violation of Section 5(a) of the Federal Trade Commission Act (FTC Act). The FTC expects companies to have reasonable and appropriate data security measures based on factors such as data sensitivity and volume, the complexity of the business, and available resources. Health information is considered sensitive data that merits stronger safeguards. There are also state consumer protection laws, which may be modeled on the FTC Act, that can also provide state-law causes of action for allegedly unfair or deceptive acts or practices, among other things.

While we may not currently be subject to any comprehensive state privacy laws (e.g., the CCPA) due to applicability or exemption considerations, the legal landscape is rapidly changing. If we were to become subject to these laws, we would be required to comply with the demanding obligations they impose with respect to personal information. Furthermore, if our service providers, partners or collaborators are subject to such laws, we may have contractual obligations relating to these requirements.

The collection and processing of personal data, including personal health data related to individuals in the EEA regardless of citizenship or residence, is governed by the provisions of the General Data Protection Regulation 2016/679 (GDPR) which provides for significant monetary fines for noncompliance. The GDPR regulates (i) the processing of personal data carried out in the context of the activities of a company established in the EEA; and (ii) the processing of personal data carried out by a company not established in the EEA where such processing relates to (a) the offering of goods or services to data subjects who are in the EEA or (b) the monitoring of the behavior of data subjects who are in the E.U. The GDPR imposes a number of requirements, including requirements related to the legal basis of the processing (such as consent of the individuals to whom the personal data relates), the information provided to the individuals prior to processing their personal data, the personal data breaches which may have to be notified to the national data protection authorities and data subjects, the measures to be taken when engaging processors, and the security and confidentiality of the personal data. E.U. Member States and EEA countries may also impose additional requirements in relation to health, genetic and biometric data through their national implementing legislation.

Further, from January 1, 2021, in addition to the GDPR, companies have to comply with the UK GDPR, which, together with the amended UK Data Protection Act 2018, retains the GDPR in UK national law. The UK GDPR mirrors the fines under the GDPR, i.e., fines up to the greater of £17.5 million or 4% of global turnover. Furthermore, the passage of the Data (Use and Access) Act 2025 (DUAA), which received Royal Assent in June 2025, introduced new obligations. These include mandatory internal complaint mechanisms, and aligning the maximum fines of the Privacy and Electronic Communications Regulations (PECR) with UK GDPR levels. Notably for our operations, the DUAA provides a more expansive statutory definition of scientific research that explicitly includes commercial and privately funded activities, and it permits the use of "broad consent" for future research purposes where specific goals cannot be fully identified at the outset.These changes may lead to additional costs and increase our overall risk exposure. The European Commission has adopted an adequacy decision in favor of the UK, enabling personal data transfers from E.U. member states to the UK without additional safeguards. The European Commission renewed the UK adequacy decision on December 19, 2025 for a period of six years until December 27, 2031, with the possibility to be renewed after this period. In addition, transfers of personal data from the UK to other countries, including the EEA, are subject to specific transfer rules under the UK regime. Personal data may freely flow from the UK to the EEA, since the EEA is deemed to have an adequate data protection level for purposes of the UK regime. These UK international transfer rules broadly mirror the E.U. GDPR rules. With regard to the transfer of personal data from the UK to the U.S., from October 12, 2023, businesses in the UK can start to transfer personal data to U.S. organizations certified

Table of Contents

to the "UK Extension to the EU-US Data Privacy Framework" (UK Extension) under the UK GDPR, without the need for further safeguards. On March 21, 2022, the international data transfer agreement (IDTA) and the international data transfer addendum to the European Commission's standard contractual clauses (SCCs) for international data transfers (Addendum), and a document setting out transitional provisions, came into force and replaced the prior EU SCCs for purposes of the UK regime.

Failure to comply with the requirements of GDPR and/or UK GDPR, and the related national data protection laws of the E.U. Member States or the UK may result in fines and other administrative penalties, litigation, government enforcement actions (which could include civil and/or criminal penalties), and harm our business. Moreover, patients about whom we or our partners obtain information, as well as the providers who share this information with us, may have contractual rights that may limit our ability to use this information. Claims that we have violated patient’s or any individual's rights or breached our contractual obligations, even if ultimately we are not found liable, could be expensive and time-consuming to defend, and could result in adverse publicity and harm our business.

Significant disruptions in our information technology systems or breaches of data security could adversely affect our business.

We rely on information technology systems to keep financial records, maintain corporate records, communicate with staff and external parties and operate other critical functions. Our information technology systems are potentially vulnerable to disruption due to breakdown, malicious intrusion and computer viruses or other disruptive events, including, but not limited to, natural disasters, terrorist attacks, utility outages, theft, viruses, phishing, malware, design defects, human error and complications encountered as existing systems are maintained, repaired, replaced or upgraded. If we were to experience a prolonged disruption in our information technology systems or those of our vendors or other third parties upon whom we rely, it could negatively impact our ability to operate our business and serve our customers, which could adversely impact our business. Although we maintain offsite back-ups of our data, if our operations were disrupted, it may cause a material disruption to our business if we are unable to restore systems, data and functions in an acceptable time frame. In addition, our information technology systems are potentially vulnerable to data security breaches — whether by employees or others — which may expose data (including sensitive data) to unauthorized persons. Such data security breaches could lead to the loss of trade secrets or other intellectual property, or to the public exposure of personal data (including sensitive personal data) of our employees, customers and others, any of which could have a material adverse effect on our business, reputation, financial condition and results of operations. Sensitive data could also be compromised, disclosed, or revealed in connection with the use or misuse of AI or other automated tools by our employees, personnel, vendors or partners. In addition, because we collect, store and transmit confidential information in digital form, we, and third parties with whom we work, are or may become subject to numerous domestic and foreign laws, regulations and standards relating to privacy, data protection and data security. The scope of these requirements is evolving, subject to differing applications and interpretations, and may be inconsistent among jurisdictions or conflict with one another. Any data breaches, security incidents or other loss of information could result in legal claims or proceedings, regulatory investigations, liability under laws that protect personal information, including state data privacy and breach notification laws, the E.U. GDPR and the UK GDPR, which could result in significant penalties. In addition, these breaches and other unauthorized access can be difficult to detect, and as threat actors increasingly leverage AI and other advanced technologies, cyber attacks and security incidents may become more frequent, sophisticated and harder to identify, and it may take considerable time for us to investigate and evaluate the full impact of cyber attacks, particularly for sophisticated attacks, which may inhibit our ability to provide prompt, full, and reliable information about cybersecurity incidents to our customers, regulators, and the public. Any delay in identifying or responding to cyberattacks and security incidents may lead to increased harm of the type described above.

Additionally, we are or may become subject to contractual obligations related to data privacy, protection and security, and such obligations may change or expand as our business grows. The actual or perceived failure by us, or by third parties related to us, to comply with such laws, regulations and obligations could increase our compliance and operational costs, expose us to regulatory scrutiny, actions, fines and penalties, result in reputational harm, lead to a loss of business, result in litigation and liability, and otherwise cause a material adverse effect on our business, financial condition, and results of operations.

Although we utilize various procedures and controls designed to help mitigate these risks, cyber attacks and other cyber events are evolving, unpredictable and increasing in sophistication, including through the use of advanced and evolving technologies, such as AI. Moreover, the information technology systems of our third-party partners, including suppliers, manufacturers, service providers and others on which we rely, may be subject to similar risks. While we maintain cybersecurity insurance coverage for certain security incidents, we cannot ensure that it will be sufficient in type or amount to cover any particular losses we may experience. Any significant security incident could have a material adverse effect on our business, financial condition and results of operations.

We are subject to extensive federal and state laws and regulations relating to the submission of claims for payment for services, including those that relate to coverage of services under Medicare, Medicaid, and other governmental healthcare programs, the amounts that may be billed for services, and to whom claims for services may be submitted, such as billing Medicare as the secondary,

Table of Contents

rather than the primary, payor. The failure to comply with applicable laws and regulations, for example, enrollment in the Medicare Provider Enrollment, Chain and Ownership System, could result in our inability to receive payment for our services or attempts by third party payors, such as Medicare and Medicaid, to recover payments from us that we have already received. Submission of claims in violation of certain statutory or regulatory requirements can result in penalties, damages and exclusion from participation in Medicare and Medicaid. Government authorities and private whistleblowers may also assert that violations of laws and regulations related to submission of claims violate the federal False Claims Act or other laws related to fraud and abuse, including submission of claims for services that were not medically necessary. The Company will be generally dependent on independent physicians to determine when its services are medically necessary for a particular patient. Nevertheless, we could be adversely affected if it were determined that the services we provided were not medically necessary and not reimbursable, particularly if it were asserted that we contributed to the physician’s referrals of unnecessary services. It is also possible that the government could attempt to hold us liable under fraud and abuse laws for improper claims submitted by us if it were found that we knowingly participated in the arrangement that resulted in submission of the improper claims.

In addition to the Patient Protection and Affordable Care Act (the PPACA), the effect of which cannot presently be quantified, various healthcare reform proposals have also emerged from federal and state governments. Changes in healthcare policy could adversely affect our business.

We cannot predict whether future healthcare initiatives will be implemented at the federal or state level or in countries outside of the U.S. in which we may do business, or the effect any future legislation or regulation will have on us. The taxes imposed by any new federal legislation and the expansion in government’s effect on the U.S. healthcare industry, including the Inflation Reduction Act enacted in August 2022, may result in decreased profits to us, lower reimbursements by payors for our products or reduced medical procedure volumes, all of which may adversely affect our business, financial condition and results of operations.

We face significant competition from other biotechnology and pharmaceutical companies.

Our product candidates face, and will continue to face, intense competition from large pharmaceutical and biotechnology companies, as well as academic and research institutions. We compete in an industry that is characterized by (i) rapid technological change, (ii) evolving industry standards, (iii) emerging competition and (iv) new product introductions. Our competitors have existing products that compete with our product candidates and they may develop and commercialize additional products that will compete with our product candidates. Because competing companies and institutions may have greater financial resources than us, they may be able to provide broader services and product lines, make greater investments in research and development or carry on broader R&D initiatives. Our competitors also have greater development capabilities than we do and have substantially greater experience in undertaking preclinical and clinical testing of product candidates, obtaining regulatory approvals and manufacturing and marketing pharmaceutical products.

We also compete with a substantial number of other companies that are working to develop novel drugs using emerging AI technologies that compete directly or indirectly with us. Companies implementing generative AI, for example, have been devoting resources to create large and high-quality training datasets in order to accelerate drug discovery processes. This includes using AI tools to create novel drug molecules, streamline disease target identification, and construct AI-based prediction models for clinical trial outcomes. As a result of these dynamics, we may not be able to secure the technologies we desire or to otherwise effectively compete. Furthermore, should any commercial undertaking by us prove to be successful, there can be no assurance competitors with greater financial resources will not offer competitive products and/or technologies.

Even if we obtain regulatory approval for our products, we may not be the first to market and that may affect the price or demand for our potential products. Existing or future competing products may provide greater therapeutic convenience or clinical or other benefits for a specific indication, or fewer side effects, than our potential products or may offer comparable performance at a lower cost. Additionally, the availability and price of our competitors’ products could limit the demand and the price we are able to charge for our potential products thereby reducing or eliminating our commercial opportunity. We may not be able to implement our business plan if the acceptance of our potential products is inhibited by price competition or the reluctance of physicians to switch from existing methods of treatment to our potential products, or if physicians switch to other new products or choose to reserve our potential products. Additionally, a competitor could obtain orphan product exclusivity from the FDA with respect to such competitor’s product, which may prevent us from obtaining approval from the FDA for such potential products for the same indication for a period of time. If our potential products fail to capture and maintain market share, we may not achieve sufficient product revenues and our business will suffer.

Our employees and third-party partners may engage in misconduct or other improper activities, including noncompliance with regulatory standards and requirements.

We are exposed to the risk of employees’ or our third-party partners’ fraud or other misconduct. Misconduct by our employees or partners could include intentional failures to comply with FDA regulations, provide accurate information to the FDA, comply with manufacturing standards, comply with federal and state healthcare fraud and abuse laws and regulations, report financial information or data accurately or disclose unauthorized activities to us. Employee and third-party misconduct could involve the improper use of

Table of Contents

information obtained in the course of clinical trials, which could result in regulatory sanctions and serious harm to our business and our reputation. It is not always possible to identify and deter such misconduct, and the precautions we take to detect and prevent this activity may not be effective in controlling unknown or unmanaged risks or losses or in protecting us from governmental investigations or other actions or lawsuits stemming from a failure to be in compliance with such laws or regulations. If any such actions are instituted against us and we are not successful in defending ourselves or asserting our rights, those actions could have a material adverse effect on our business, financial condition and results of operations, and result in the imposition of significant fines or other sanctions against us.

Our business involves risk associated with handling hazardous and other dangerous materials.

Our research and development activities involve the controlled use of hazardous materials, chemicals, human blood and tissue, animal blood and blood products, animal tissue, and biological waste. The risk of accidental contamination or injury from these materials cannot be completely eliminated. The failure to comply with current or future regulations could result in the imposition of substantial fines against the Company, suspension of production, alteration of our manufacturing processes or cessation of operations.

Risks Related to the Securities Markets and Investment in our Securities.

Our shares of common stock are listed on the Nasdaq Capital Market (Nasdaq), and as such, we are required to satisfy the continued listing standards of Nasdaq to maintain our listing. However, we cannot assure you that we will be able to maintain compliance with the continued listing standards of Nasdaq, including its minimum closing bid price requirement, or satisfy the continued listing standards of Nasdaq going forward.

For example, on February 21, 2025, we were notified by Nasdaq that we were not in compliance with Nasdaq Listing Rule 5550(a)(2), because our common stock failed to maintain a minimum closing bid price of $1.00 per share for 30 consecutive business days. On February 2, 2026, we effected a 1-for-15 reverse stock split, and our common stock began trading on a split-adjusted basis (above $1 per share) at the opening of the market on February 2, 2026. To regain compliance, we were required to maintain a minimum closing bid price of $1.00 per share for at least 10 consecutive trading days. This requirement was met as of the close of trading on February 13, 2026.

If we are unable to comply with the continued listing standards of Nasdaq, including Nasdaq Listing Rule 5550(a)(2). Nasdaq may commence delisting procedures against us, which could result in our stock being removed from listing on Nasdaq, and we could face significant material adverse consequences, including:

•

stock price volatility;

•

limited availability of market quotations for our common stock;

•

reduced liquidity with respect to our common stock;

•

a determination that our shares are "penny stock," which will require brokers trading in our shares to adhere to more stringent requirements, and which may limit demand for our common stock among certain investors;

•

limited news and analyst coverage on the Company; and

•

decreased ability to issue additional securities or obtain additional financing in the future.

The sale of a substantial number of shares of our common stock into the market may cause substantial dilution to our existing stockholders and the sale, actual or anticipated, of a substantial number of shares of common stock could cause the price of our common stock to decline.

We have offered and sold a considerable amount of our common stock in past financings. Any additional or anticipated sales of shares by us, including through “at the market” offerings pursuant to our Sales Agreement with the Sales Agent, sales by holders of our warrants to purchase our common stock or sales by other stockholders may cause the trading price of our common stock to decline. Additional issuances of shares by us may result in dilution to the interests of other holders of our common stock. The sale of a substantial number of shares of our common stock by us, our warrant holders or other stockholders or anticipation of such sales, could make it more difficult for us to sell equity or equity-related securities in the future at a time and at a price that we might otherwise wish to effect sales.

The trading price of our common stock has been and is likely to continue to be volatile.

Table of Contents

Our stock price is highly volatile. In addition to the factors discussed in this Annual Report, the trading price of our common stock may fluctuate significantly in response to numerous factors, many of which are beyond our control including:

•

price and volume fluctuations in the overall stock market;

•

changes in operating results and performance and stock market valuations of other biopharmaceutical companies generally;

•

macroeconomic, industry, geopolitical and market conditions, including, but not limited to, high interest rates, the inflationary environment, general economic slowdown or a recession, foreign exchange rate volatility, financial institution instability, government shutdowns, changes in monetary policy, changes in trade policies including tariffs and other trade restrictions or the threat of such actions, and rising geopolitical instability, including the ongoing conflict in Ukraine, the conflict in the Middle East, and rising tensions between China and Taiwan;

•

financial or operational projections we may provide to the public, any changes in these projections or our failure to meet these projections;

•

changes in government regulations;

•

our inclusion or removal from certain stock indices;

•

developments in patent or other proprietary rights;

•

new products by our competitors;

•

announcements of changes in our senior management or directors;

•

other events, including those resulting from war, incidents of terrorism, natural disasters, severe weather, pandemics, or responses to these events;

•

public statements made by third parties, including trial participants and clinical investigators, regarding our current or future clinical trials that may harm our reputation;

•

changes in accounting principles;

•

results of clinical studies;

•

regulatory and FDA actions, including inspections and warning letters;

•

coverage of us, and changes in financial estimates by any securities analysts who follow our Company, or our failure to meet these estimates or the expectations of investors;

•

any ongoing litigation that we are currently involved in or litigation that we may become involved in the future;

•

additional shares of our common stock being sold into the market by us or our existing stockholders or warrant holders or the anticipation of such sales; and

•

media coverage of our business and financial performance.

In addition, the stock markets have experienced extreme price and volume fluctuations that have affected and continue to affect the market prices of equity securities of many healthcare companies. Stock prices of many healthcare companies have fluctuated in a manner unrelated or disproportionate to the operating performance of those companies. As a result, an investment in our common stock may decrease in value.

We have never paid dividends, and we do not anticipate paying dividends in the future.

We have never declared or paid dividends on our capital stock. We currently intend to retain all of our future earnings, if any, to finance the growth, development, operation and expansion of our business, and we do not anticipate declaring or paying any dividends for the foreseeable future. As a result, capital appreciation, if any, of our common stock will be stockholders’ sole source of gain for the foreseeable future.

The ownership of our common stock may become concentrated among a small number of stockholders, and if our principal stockholders, directors and officers choose to act together, they may be able to significantly influence management and operations, which may prevent us from taking actions that may be favorable to stockholders.

Our ownership may become concentrated among a small number of stockholders. These stockholders, acting together, could have the ability to exert substantial influence over all matters requiring approval by our stockholders, including the election and removal of directors and any proposed merger, consolidation or sale of all or substantially all of our assets. This concentration of ownership could also have the effect of delaying, deferring, or preventing a change in control of the Company or impeding a merger or consolidation, takeover or other business combination that could be favorable to stockholders.

If we are unable to implement and maintain effective internal control over financial reporting in the future, investors may lose confidence in the accuracy and completeness of our financial reports and the trading price of our common stock may be negatively affected.

Table of Contents

We are required to maintain internal controls over financial reporting and to report any material weaknesses in such internal controls. If we identify material weaknesses in our internal control over financial reporting, or if we are unable to comply with the requirements of the Sarbanes-Oxley Act in a timely manner or assert that our internal control over financial reporting is effective, investors may lose confidence in the accuracy and completeness of our financial reports and the trading price of our common stock could be negatively affected, and we could become subject to investigations by the stock exchange on which our securities are listed, the SEC, or other regulatory authorities, which could require additional financial and management resources.

The anti-takeover provisions in our governing documents and Delaware law could delay or prevent a change in control which could reduce the market price of our common stock and could prevent or frustrate attempts by our stockholders to replace or remove our current management and the current Board.

Our Amended and Restated Certificate of Incorporation, as amended, and our Amended and Restated Bylaws contain provisions that could delay or prevent a change in control or changes in our Board that our stockholders might consider favorable. These provisions include a staggered Board, which divides the Board into three classes, with directors in each class serving staggered three-year terms. The existence of a staggered board can make it more difficult for a third party to effect a takeover of our Company if the incumbent Board does not support the transaction. These and other provisions in our corporate documents, and Delaware law, might discourage, delay or prevent a change in control or changes in our Board. These provisions could also discourage proxy contests and make it more difficult for activist investors and other stockholders to elect directors not nominated by our Board. Furthermore, the existence of these provisions, together with certain provisions of Delaware law, might hinder or delay an attempted takeover other than through negotiations with our Board.

Our Amended and Restated Certificate of Incorporation provides that the Court of Chancery of the State of Delaware will be the exclusive forum for substantially all disputes between us and our stockholders, which could limit our stockholders' ability to obtain a favorable judicial forum for disputes.

Our Amended and Restated Certificate of Incorporation, as amended, provides that the Court of Chancery of the State of Delaware is the exclusive forum for certain actions. The exclusive forum provision may limit a stockholder’s ability to bring a claim in a judicial forum that it finds favorable for disputes, which may discourage lawsuits. In addition, there is uncertainty as to whether a court would enforce such a provision. If a court were to find these types of provisions to be inapplicable or unenforceable, and if a court were to find the exclusive forum provision in our Amended and Restated Certificate of Incorporation, as amended, to be inapplicable or unenforceable in an action, we may incur additional costs associated with resolving the dispute in other jurisdictions, which could materially and adversely affect our business.

If securities or industry analysts do not publish research or publish inaccurate or unfavorable research about our business, the price of our common stock and trading volume could decline.

The trading market for our common stock will depend in part on the research and reports that securities or industry analysts publish about us or our business. Multiple securities and industry analysts currently cover us. If one or more of the analysts downgrade our common stock or publish inaccurate or unfavorable research about our business, the price of our common stock would likely decline. If one or more of these analysts cease coverage of us or fail to publish reports on us regularly, demand for our common stock could decrease, which could cause the price of our common stock and trading volume to decline.

Table of Contents

ITEM 1B. UNRESOLVED STAFF COMMENTS

Not applicable.

ITEM 1C. CYBERSECURITY

In the ordinary course of our business, we use, store, and transmit confidential, sensitive, proprietary, personal, and health-related information. The secure maintenance of this information and our information technology systems is important to our operations and business strategy. To this end, we have implemented processes designed to help assess, identify, and manage risks from potential unauthorized occurrences on or through our information technology systems that may result in adverse effects on the confidentiality, integrity, and availability of these systems and the data residing therein. These processes are managed and monitored by a third-party information technology vendor, which is overseen by our Senior Vice President of Business Operations, and include mechanisms, controls, technologies, systems, and other processes designed to help prevent or mitigate data loss, theft, misuse, or other security incidents or vulnerabilities affecting the data and help maintain a stable information technology environment. For example, we conduct vulnerability and data penetration testing, regularly review third-party audits of our cloud-based technology vendors and perform ongoing regular risk assessments. We also conduct periodic employee training on cyber and information security, among other topics. In addition, to our third-party information technology vendor, we also consult with outside advisors and experts, when appropriate, to assist with assessing, identifying, and managing cybersecurity risks, including to help anticipate future threats and trends, and their impact on the Company’s risk environment.

Our Senior Vice President of Business Operations, who reports directly to our Chief Executive Officer and has over nine years of experience managing information technology and cybersecurity matters, together with our senior leadership team, is responsible for assessing and managing cybersecurity risks.We consider cybersecurity, along with other significant risks that we face, within our overall enterprise risk management framework. Since the beginning of the last fiscal year, we have not identified risks from known cybersecurity threats, including as a result of any prior cybersecurity incidents, that have materially affected us, but we face certain ongoing cybersecurity risks threats that, if realized, are reasonably likely to materially affect us. Additional information on cybersecurity risks we face is discussed in "PART I, ITEM 1A, RISK FACTORS," under the heading "Significant disruptions in our information technology systems or breaches of data security could adversely affect our business".

The Board of Directors (the Board), as a whole, has oversight for the most significant risks facing us and for our processes to help identify, prioritize, assess, manage, and mitigate those risks. The Board receives at least quarterly updates on cybersecurity and information technology matters and related risk exposures from our Senior Vice President of Business Operations as well as other members of the senior leadership team.

ITEM 2. PROPERTIES

We have an operating lease with 1448 NW Market Street Tenant LLC for office space in Seattle, Washington. The lease commencement date was November 1, 2025 and we agreed to pay $3 thousand per month for 13 months.

ITEM 3. LEGAL PROCEEDINGS

We are, and from time to time we may become, involved in legal proceedings or be subject to claims arising in the ordinary course of our business. For a discussion of our legal proceedings, refer to Note 13 to the Consolidated Financial Statements. We are not presently a party to any other legal proceedings that in the opinion of our management, if determined adversely to us, would individually or taken together have a material adverse effect on our consolidated results of operations, financial condition or cash flows.

ITEM 4. MINE SAFETY DISCLOSURES

Not applicable.

Table of Contents

PART II

ITEM 5. MARKET FOR THE REGISTRANT’S COMMON EQUITY, RELATED STOCKHOLDER MATTERS AND ISSUER PURCHASES OF EQUITY SECURITIES

Market Information

Our common stock, par value $0.18 per share, trades on the Nasdaq Capital Market under the symbol "ATOS."

Stockholders

As of March 17, 2026, there were approximately 33 stockholders of record of our common stock, one of which is Cede & Co., a nominee for Depository Trust Company (DTC). All of the shares of common stock held by brokerage firms, banks and other financial institutions as nominees for beneficial owners are deposited into participant accounts at DTC and are therefore considered to be held of record by Cede & Co. as one stockholder.

Dividends

We have never declared or paid any cash dividends on our common stock and do not currently anticipate declaring or paying cash dividends on our common stock in the foreseeable future. We currently intend to retain any future earnings to finance the growth and development of our business. Any future determination relating to our dividend policy will be made at the discretion of our Board and depends on a number of factors, including future earnings, capital requirements, financial conditions, future prospects, contractual restrictions and other factors that our Board may deem relevant.

Issuer Purchases of Securities

We did not repurchase any of our equity securities during the fourth quarter of fiscal 2025.

Unregistered Sales of Equity Securities and Use of Proceeds

None.

ITEM 6. RESERVED

Table of Contents

ITEM 7. MANAGEMENT'S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND RESULTS OF OPERATIONS

The following discussion of our financial condition and results of operations should be read in conjunction with the Consolidated Financial Statements and the related notes included elsewhere in this Annual Report. This discussion contains forward-looking statements, which are based on assumptions about the future of our business. Actual results, outcomes and the timing of results or outcomes could differ materially from those contained in the forward-looking statements. Please read "Note Regarding Forward-Looking Statements"included elsewhere in this Annual Report for additional information regarding forward-looking statements.

Company Overview

We are a clinical-stage biopharmaceutical company developing proprietary innovative medicines in areas of significant unmet medical need in oncology, with a focus on breast cancer and other breast conditions, as well as certain rare diseases. Our lead drug candidate is oral (Z)-endoxifen, a selective estrogen receptor modulator (SERM)/ selective estrogen receptor degrader (SERM/D) currently in Phase 2 clinical development. The Company is evaluating potential indications for (Z)-endoxifen based on its pharmacologic profile, including its potential for both reducing the risk of and for the treatment of breast cancer, as well as in other therapeutic areas.

We have been granted seven U.S. and 16 international patents covering our proprietary (Z)-endoxifen, and we have numerous applications pending in the U.S. and in other major countries. We expect to have patent protection covering our proprietary (Z)-endoxifen through at least November 17, 2038.

Our business strategy is to advance our programs through clinical studies, including with potential partners, and opportunistically add programs in areas of high unmet medical need through acquisition, minority investment, collaboration or internal development.

(Z) endoxifen. (Z)-endoxifen is the most active metabolite of Tamoxifen, a U.S. Food and Drug Administration (FDA) approved drug to treat and prevent breast cancer in high-risk women, and it is substantially more potent as an estrogen receptor antagonist than Tamoxifen and other approved SERMs. Unlike Tamoxifen, which requires metabolic activation through CYP2D6 and other liver enzymes, (Z)-endoxifen does not require first-pass metabolism to achieve therapeutic concentrations. As a result, its activity is not dependent on patient-specific metabolic variability.

(Z)-endoxifen is a small-molecule oral agent designed to directly inhibit estrogen receptor signaling, induce estrogen receptor degradation, and promote apoptosis in estrogen receptor positive (ER+) breast cancer cells. Preclinical and clinical data suggest that (Z)-endoxifen may inhibit clinically relevant ESR1 mutations associated with resistance to aromatase inhibitors and may also inhibit protein kinase C beta one (PKCβ1), resulting in downregulation of the AKT signaling pathway. We are evaluating (Z)-endoxifen across multiple settings within the ER+/human epidermal growth factor receptor 2 negative (HER2-) breast cancer treatment continuum, including neoadjuvant, adjuvant and breast density reduction indications.

In an ongoing neoadjuvant clinical study, (Z)-endoxifen has demonstrated early signs of anti-tumor activity. Reported results include one complete response and multiple partial responses, as well as substantial reductions in Ki-67 proliferation across dose levels. Tumor shrinkage was observed by MRI imaging, which is atypical for endocrine therapies that are generally cytostatic.

We are also supporting multiple collaborative and investigator-sponsored clinical studies evaluating (Z)-endoxifen in additional breast cancer settings. These studies are not fully funded by us and are intended to further characterize clinical activity, optimize endocrine therapy strategies, and inform future regulatory pathways.

Based on its mechanism of action, we are exploring the potential application of (Z)-endoxifen beyond breast cancer, including gynecological cancers, endocrine resistance driven by ESR1 mutations, as well as applications in other rare disease indications, including Duchenne Muscular Dystrophy (DMD), women carriers of DMD, and McCune-Albright Syndrome (MAS) in girls. In preclinical models of DMD, (Z)-endoxifen demonstrated muscle-protective, anti-inflammatory, and anti-fibrotic effects. We believe similar efficacy could potentially apply to women carriers of DMD. For MAS, we believe (Z)-endoxifen could potentially be an effective hormone blocker, significantly reducing the effects of early onset puberty in young girls. We have developed a proprietary manufacturing process for (Z)-endoxifen, including defined processes for the active pharmaceutical ingredient and drug product. The drug product is available in multiple dosage strengths and is supported by qualified suppliers and manufacturing redundancies.

Summary of Our Leading Programs

We are developing a proprietary form of (Z)-endoxifen which is administered orally for the potential treatment of high-risk breast cancer and the reduction of mammographic breast density (MBD). As part of this development, we are also evaluating the potential for (Z)-endoxifen to work in combination with other cancer treatment therapies for premenopausal and postmenopausal women with high-risk breast cancer.

In addition to oncology related indications, we believe (Z)-endoxifen has potentially broader utility as a therapeutic platform in serious and rare diseases, many of which have significant unmet medical need. There is growing scientific evidence supporting the

Table of Contents

potential role of estrogen signaling modulation in muscle preservation and inflammation associated with conditions, such as DMD and MAS, among others.

The following is a summary of the status of our major oncology and rare disease clinical development programs as of the date of this Annual Report:

Oncology/Breast Cancer

In support of our breast cancer risk reduction and treatment indications, we have completed four Phase 1 clinical studies (including a study in men) and two Phase 2 clinical studies with our proprietary (Z)-endoxifen (including oral and topical formulations). We have also completed significant pre-clinical development and have developed clinical manufacturing capabilities through qualified third parties.

Karisma Study

(Z)-endoxifen for Women with Mammographic Breast Density. MBD is an emerging public health issue. Almost half of the women in the world over the age of 40 have dense breasts, and there are currently no approved treatments to reduce breast density. Elevated breast density can make a mammogram more difficult to interpret because dense breast tissue and some abnormal breast changes, such as calcifications and tumors, appear as white areas in a mammogram. Women with the highest density are four to six times more likely to develop breast cancer in their lifetime and more likely to develop cancer between mammograms compared to those with low breast density. The latter are sometimes referred to as "interval cancers," which are often larger, more advanced, and more difficult to treat.

In December 2021, we commenced a Phase 2 study of our proprietary oral (Z)-endoxifen. The study, known as the Karisma-(Z)-endoxifen study, was a Phase 2, randomized, double-blind, placebo-controlled, dose-response study of our proprietary oral (Z)-endoxifen in healthy premenopausal women with measurable MBD. The primary objective of the study was to determine the dose-response relationship of daily (Z)-endoxifen on breast density reduction. Secondary endpoints assessed safety and tolerability. The study was conducted in Stockholm, Sweden and included approximately 240 participants who received daily doses of oral (Z)-endoxifen or placebo for six months after enrollment, randomized to one of three arms: placebo, 1 mg of (Z)-endoxifen, or 2 mgs of (Z)-endoxifen. The study also included an exploratory endpoint to assess twenty-four month durability of the breast density changes. Top line data for this study measuring both MBD reduction after six months of treatment and data regarding twenty-four month durability is expected in the first quarter of 2026.

The study fully enrolled in November 2023 and in September 2024, the primary objective measuring MBD after six months of treatment, was concluded. The data showed the potential of low-dose (Z)-endoxifen to significantly reduce MBD with a favorable safety profile.

The 1 mg dose of (Z)-endoxifen reduced MBD by 17.3% (p<0.01), while the 2 mg dose achieved a reduction of 23.5% (p<0.01), compared to a minimal change in the placebo group of 0.27%. Plasma concentrations for (Z)-endoxifen were measured at 4.8 ng/mL and 9.7 ng/mL for the 1 mg and 2 mg arms, respectively, demonstrating the effectiveness of the lower dose in achieving significant MBD reductions. Importantly, no significant differences in adverse events were observed between the 1 mg dose and the placebo. The 2 mg dose was associated with higher rates of hot flashes, night sweats and vaginal discharge.

We expect to report top-line data from the Karisma (Z)-endoxifen study in the first half of 2026. Further development will depend on regulatory guidance, study outcomes, and available resources.

RECAST DCIS Study

Ductal Carcinoma in Situ (DCIS) is the presence of abnormal cells inside a milk duct in the breast. It rarely produces symptoms, or a breast lump one can feel, and is typically detected through screening mammography. In some cases, DCIS may become invasive and spread to other tissues, but there is no way of determining which lesions will remain stable without treatment and which will go on to become invasive. This uncertainty can result in aggressive and unnecessary treatment approaches that can have harmful side effects without significant benefit.

In October 2023, the Quantum Leap Healthcare Collaborative (the QLHC) announced the initiation of the Phase 2 DCIS: Re-Evaluating Conditions for Active Surveillance Suitability as Treatment (the RECAST) study. (Z)-endoxifen is being investigated as part of this platform trial, which offers women with DCIS six months of neoadjuvant treatment with the intent of determining their suitability for long-term active surveillance without surgery. Approximately 100 patients are expected to be treated with (Z)-endoxifen. The study incorporates both a neoadjuvant therapy phase, with patients at high risk for progression to invasive disease proceeding to surgery, followed by an extended surveillance phase for low-risk patients. Enrollment in this study is ongoing.

EVANGELINE Study

We are also developing (Z)-endoxifen to treat estrogen receptor positive (ER+) / human epidermal growth factor receptor 2 negative (HER2-) breast cancer in the neoadjuvant setting, which is the administration of a therapy before the main treatment, which is usually surgery. Although there are neoadjuvant treatments for breast cancers that are not ER+, there are few neoadjuvant treatments for ER+ breast cancer which comprises approximately 240,000 new cases or approximately 80% of all breast cancers each year.

Table of Contents

In October 2022, we received authorization from the FDA for our Investigational New Drug (IND) application for oral (Z)-endoxifen. The study, known as "EVANGELINE," is a Phase 2 randomized study designed to assess (Z)-endoxifen as neoadjuvant therapy in premenopausal women with primary ER+/HER2– breast cancer. As originally designed, the study was to consist of two parts: Part 1 was a Pharmacokinetic (PK) Run-In Cohort evaluating daily dosing of 40 mg and 80 mg to assess if a plasma steady state concentration (Css) of 500 to 1000 ng/mL, which is required for optimal PKC-β inhibition, could be achieved; and Part 2 was expected to compare the two treatment arms based on baseline Ki-67 levels, with the aim of evaluating the endocrine sensitive disease rate, pathologic complete response, and other key endpoints.

Data showed that none of the patients in the 40 mg cohort reached the target Css. However, in the 80 mg cohort, approximately 50% of patients receiving (Z)-endoxifen with goserelin and 38% of patients receiving (Z)-endoxifen alone attained the target plasma Css, with an average of 484 ng/mL. Importantly, tumor Css levels were found to be more than double the plasma levels, exceeding 500 ng/g in 90% of patients, and 85% of patients exhibited a 4-week Ki-67 response (≤10%), indicating substantial tumor suppression. (Z)-endoxifen was generally well tolerated, with no significant Grade 3 or 4 toxicities, although four gynecologic events (including one Grade 3 hemorrhagic ovarian cyst) were noted in the 80 mg group.

Based on preliminary results from the 40 mg and 80 mg cohorts, the EVANGELINE study design and treatment protocol were amended in 2025. The study design has been updated to a single-arm, open-label, Phase 2 in premenopausal women with ER+/HER2– breast cancer in the pre-surgical setting. The study includes two Cohorts: Cohort A (signal-seeking), a two-stage futility design assessing the Week-4 Ki-67 ≤10% rate to allow early stop if not promising, and Cohort B (estimation), assessing Week-24 objective response (RECIST 1.1, central review). The amended design will focus on objective, short-interval endpoints to inform development decisions efficiently while working to preserve patient safeguards.

The initial EVANGELINE study design included enrollment estimates for 214 patients and has been amended to reduce enrollment totals to 40-65 patients. Enrollment in this study is ongoing, and it is expected to be complete in the second quarter of 2026.

I-SPY 2 Endocrine Optimization Pilot Study

In March 2023, a second neoadjuvant Phase 2 trial investigating oral (Z)-endoxifen as a treatment for women diagnosed with locally advanced ER+/HER2- breast cancer was initiated. This trial is a study arm in the ongoing I‐SPY 2 Endocrine Optimization Pilot (I-SPY 2 EOP) which is a collaborative effort among academic investigators from major cancer research centers across the U.S., QLHC, the FDA, and the Foundation for the National Institutes of Health (FNIH) Cancer Biomarkers Consortium. This study included twenty women who received 10 mg of (Z)-endoxifen (monotherapy) orally once daily for six cycles (each cycle = 28 days) or up to 24 weeks prior to surgery.

For the monotherapy arm of I-SPY 2 EOP, enrollment was completed in January 2024 and 3-week preliminary data results were reported in October 2024. In May 2025, we reported updated results from this study which found that (i) 95% of participants (19/20 participants) completed at least 75% of planned dosing, (ii) median Ki-67 fell from 10.5% at baseline to 5% by Week 3, (iii) 65% of patients achieved Ki-67< 10% at Week 3 with suppression maintained at surgery, (iv) median functional tumor volume measurement (performed at baseline, Week 3, Week 12 and at surgery) decreased 77.7% from baseline to surgery, and (v) the longest tumor diameter in the participants from baseline to preoperative MRI was reduced by 36.8%. (Z)-endoxifen was well tolerated in this study with the most common side effects being relatively mild, consisting of hot flashes, insomnia, and fatigue. No dose reductions or discontinuations due to treatment related adverse events occurred during this study.

In April and June of 2024, we announced our participation in two new study arms of the I-SPY 2 EOP which were initiated to evaluate our proprietary (Z)-endoxifen in combination with two FDA approved drugs: 1) abemaciclib (VERZENIO®), a cyclin-dependent kinase (CDK) 4/6 inhibitor marketed by Eli Lilly and Company, and 2) elagolix (ORILISSA®), a prescription medicine used to treat moderate to severe pain associated with endometriosis marketed by AbbVie, Inc. Total enrollment across the combination therapy arms of this study is expected to be approximately 90 enrollees. Preliminary data has not been made available related to the ongoing combination therapy arms of I-SPY 2 EOP. Enrollment in the combination therapy arms of this nearly complete, and we expect to begin receiving data in the second half of 2026.

Rare Pediatric Disease and Orphan Designations

Duchenne Muscular Dystrophy

ATOS US Equity

ATOS · 10-K · period ended 2025-12-31

ITEM 1A. RISK FACTORS

ITEM 1B. UNRESOLVED STAFF COMMENTS

ITEM 1C. CYBERSECURITY

ITEM 2. PROPERTIES

ITEM 3. LEGAL PROCEEDINGS

ITEM 4. MINE SAFETY DISCLOSURES

ITEM 5. MARKET FOR THE REGISTRANT’S COMMON EQUITY, RELATED STOCKHOLDER MATTERS AND ISSUER PURCHASES OF EQUITY SECURITIES

ITEM 6. RESERVED

ITEM 7. MANAGEMENT'S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND RESULTS OF OPERATIONS

ATOS US Equity☆

ATOS · 10-K · period ended 2025-12-31

ITEM 1A. RISK FACTORS

ITEM 1B. UNRESOLVED STAFF COMMENTS

ITEM 1C. CYBERSECURITY

ITEM 2. PROPERTIES

ITEM 3. LEGAL PROCEEDINGS

ITEM 4. MINE SAFETY DISCLOSURES

ITEM 5. MARKET FOR THE REGISTRANT’S COMMON EQUITY, RELATED STOCKHOLDER MATTERS AND ISSUER PURCHASES OF EQUITY SECURITIES

ITEM 6. RESERVED

ITEM 7. MANAGEMENT'S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND RESULTS OF OPERATIONS

ATOS US Equity