APRE 10-K & 10-Q changes, risk factors and insider trading

Since our inception, we have incurred significant losses on an aggregate basis. Our net loss was $13.0$12.6 million and $14.3$13.0 million for the years ended December 31, 20242025 and 2023,2024, respectively. Our accumulated deficit was $321.0$333.6 million as of December 31, 2024.2025. We have not generated any commercial revenue to date from sales of any drugs and have financed our operations principally through private placements of our preferred stock and the net proceeds received from the initial public offering (IPO) of our common stock. We have devoted substantially all of our efforts to research and development. We expect that it will be several years, if ever, before we have any product candidates ready for commercialization. We expect to continue to incur significant expenses and increasing operating losses for the foreseeable future. The net losses we incur may fluctuate significantly from quarter to quarter.

We are an early-stage company. Our operations to date have been limited to organizing and staffing our company, business planning, raising capital, developing our product candidates, identifying potential product candidates, conducting preclinical studies of our product candidates and conducting clinical trials of our product candidates. ATRN-119APR-1051 and APR-1051ATRN-119, are in clinical development,development and our other product candidates are in preclinical development. We have currently paused further patient enrollment in both the once daily and twice daily monotherapy dosing arms of ABOYA-119 and started the orderly wind-down of certain clinical trial site activities associated with the monotherapy arms as we explore ATTN-119 in potential combination approaches. We have not yet demonstrated our ability to successfully complete large-scale, pivotal clinical trials, obtain marketing approvals, manufacture commercial-scale drug products, or arrange for a third party to do so on our behalf, or conduct sales and marketing activities necessary for successful drug commercialization. Typically, it takes about six to ten years to develop a new drug from the time it is in Phase 1 clinical trials to when it is approved for treating patients, but in many cases it may take longer. Consequently, any predictions you make about our future success or viability may not be as accurate as they could be if we had a longer operating history.

We believe that our existing cash and cash equivalents as of December 31, 20242025 and the proceeds from our January 2026 private placement will be sufficient to meet our currently projected operating expenses and capital expenditure requirements into the first quarter of 2026.2027. Our estimate as to how long we expect our existing cash and cash equivalents to be able to continue to fund our operations is based on assumptions that may prove to be wrong, and we could use our available capital resources sooner than we currently expect. Further, changing circumstances, some of which may be beyond our control, could cause us to consume capital significantly faster than we currently anticipate, and we may need to seek additional funds sooner than planned. Our future capital requirements will depend on many factors, including:

In addition, natural and man-made disasters and global health emergencies, including pandemics and epidemics, may adversely affect the financial markets and global economy, increase inflation and result in significant business disruptions. We and our third-party services providers could be subject to the impact of natural or man-made disasters and other business disruptions, which include, but are not limited to, hurricanes, flooding, typhoons, tornados, wildfires and fires, drought, extreme heat, earthquakes, water shortages, blizzards and other extreme weather conditions, resulting in significant damage to our facilities, inventory or equipment, which could disrupt, delay or curtail our operations. Such business disruptions may also heighten the risk of power outages, telecommunications, transportation or other infrastructure failure, cybersecurity incidents or physical security breaches. The cost of insurance has increaseincreased significantly, including as a result of the impact of climate change and inflation, and we may not be able to obtain sufficient coverage at a reasonable cost to protect us against losses from such disasters and unforeseen events.

Disruptions at the FDA, the SEC and other government agencies caused by funding shortages, government shutdowns or global health emergencies oremergencies, their inability to hire, retain or deploy key leadership and other personnel, a high turnover of key leadership positions, or significant changes in policies and processes based on political considerations could prevent new or modified products from being developed, approved or commercialized in a timely manner or at all or otherwise prevent those agencies from performing normal business functions on which the operation of our business may rely, which could negatively impact our operations.

The ability of the FDA and other government agencies to review and approve new or modified products can be affected by a variety of factors, including government budget and funding levels, statutory, regulatory and policy changes, a government agency’s ability to hire and retain key personnel and accept the payment of user fees, high turnover in key leadership positions, and other events that may otherwise affect the government agency’s ability to perform routine functions. Average review times at the FDA and other government agencies have fluctuated in recent years as a result. For example, over the last several years, the U.S. government has shut down several times and certain regulatory agencies, such as the FDA and SEC, have had to furlough critical employees and stop critical activities. In addition, government funding of agencies on which our operations may rely, including those that fund research and development activities, is subject to the political process, which is inherently fluid and unpredictable. Such disruptions at the FDA and other agencies may also increase the time necessary for new therapies or modifications to approved therapies to be reviewed and/or approved by necessary government agencies, which would adversely affect our business.

We are substantially dependent on the success of ATRN-119APR-1051 and APR-1051,ATRN-119 which are in clinical development. Our clinical trials of ATRN-119APR-1051 and APR-1051ATRN-119 may not be successful. If we are unable to obtain approval for and commercialize APR-1051 and ATRN-119 or APR-1051 or experience significant delays in doing so, our business will be materially harmed.

The success of ATRN-119APR-1051 and APR-1051ATRN-119 will depend on several factors, including the following:

We do not have control over many of these factors, including certain aspects of clinical development and the regulatory submission process, potential threats to our intellectual property rights and the manufacturing, marketing, distribution and sales efforts of any future collaborator. Accordingly, we cannot assure you that we will ever be able to generate revenue through the sale of our product candidates. If we are not successful in commercializing ATRN-119APR-1051 or APR-1051,ATRN-119, or are significantly delayed in doing so, our business will be materially harmed.

We are in the early stages of testing ATRN-119APR-1051 and APR-1051ATRN-119 in Phase 1 clinical trials and we have not tested ATRN-119APR-1051 or APR-1051ATRN-119 in later phase clinical trials. The results of preclinical studies and early-stage clinical trials may not be predictive of future results in later studies or trials. Initial success in clinical trials may not be indicative of results obtained when these trials are completed or in later-stage clinical trials.

We are in the early stages of testing ATRN-119APR-1051 and APR-1051ATRN-119 in clinical trials and we have notenot tested ATRN-119APR-1051 or APR-1051ATRN-119 in later phase clinical trials. The results of preclinical studies, whether or not conducted by us, may not be predictive of the results of clinical trials, and the results of the early-stage clinical trials that we are conducting today and that we may commence in the future may not be predictive of the results of the later-phase clinical trials. For example, even if successful, the results of our Phase 1 clinical trials of our product candidates ATRN-119APR-1051 and APR-1051ATRN-119 and other product candidates may not be predictive of the results of further clinical trials of these product candidates or any of our other product candidates. In addition, initial success in clinical trials may not be indicative of results obtained when such trials are completed on in later stage clinical trials. In particular, the small number of patients in our current and planned early clinical trials may make the results of these trials less predictive of the outcome of later clinical trials. Moreover, preclinical and clinical data often are susceptible to varying interpretations and analyses, and many companies that have believed their product candidates performed satisfactorily in preclinical studies and clinical trials nonetheless have failed to obtain marketing licensure of their product candidates. Our current and future clinical trials for ATRN-119APR-1051 and APR-1051ATRN-119 may not ultimately be successful or support further clinical development. There is a high failure rate for product candidates proceeding through clinical trials. In addition, with the current pause on further patient enrollment in both once daily and twice daily monotherapy dosing arms of ABOYA-119 and the orderly wind-down of certain clinical trial site activities associated with the monotherapy arms as we explore ATTN-119 in potential combination approaches, we may be unable to advance development of ATRN-119 for monotherapy in a timely manner, if at all. Many companies in the pharmaceutical and biotechnology industries have suffered significant setbacks in clinical development even after achieving encouraging results in earlier studies. Any such setbacks in our clinical development could materially harm our business, results of operations, financial condition and prospects.

We have filed and obtained issuance of INDs for ATRN-119APR-1051 and APR-1051,ATRN-119, but we may not be able to file and obtain issuance of INDs that may be required for our other product candidates on the timelines we expect. For example, we may experience manufacturing delays or other delays with IND-enabling studies. Moreover, we cannot be sure that submission of an IND will result in the FDA allowing further clinical trials to begin, or that, once begun, issues will not arise that lead FDA, IRBs, or other authorities to suspend, terminate, or require changes to our clinical trials. Additionally, even if such regulatory and other authorities agree with the design and implementation of the clinical trials set forth in an IND, we cannot guarantee that such regulatory authorities will not change their requirements in the future. These considerations also apply to new clinical trials and changes to existing clinical trials we may submit as amendments to existing INDs or to a new IND. Any failure to file and obtain issuance of INDs on the timelines we expect or to obtain regulatory clearance or approvals for our trials may prevent us from completing our clinical trials or commercializing our products on a timely basis, if at all.

WeWhile we have assembled a team with extensive experience in the discovery, development, and commercialization of oncology drugs to support our mission of developing novel synthetic lethality-based cancer therapeutics, we have limited experience designing, conducting and enrolling subjects in clinical trials. While certain members of our management and staff have significant experience in conducting clinical trials, to date, we have not completed any clinical trials as a company. Our operations to date provide a limited basis to assess our ability to develop and commercialize our product candidates. In addition, with the current pause on further patient enrollment in both once daily and twice daily monotherapy dosing arms of ABOYA-119 and the orderly wind-down of certain clinical trial site activities associated with the monotherapy arms as we explore ATTN-119 in potential combination approaches, we may be unable to advance development of ATRN-119 for monotherapy in a timely manner, if at all.

In general, our clinical trials of APR-1051 and ATRN-119 will or currently include cancer patients who are very sick and whose health is deteriorating. We expect that patients may experience adverse events, serious adverse events or may die during their participation in our current or future clinical trials for APR-1051 and ATRN-119 or other product candidates. We cannot predict with certainty what adverse events may occur in our clinical trials. Any adverse events, serious adverse events, or deaths occurring in our clinical trials, whether related to our product candidates or not, could affect perceptions relating to our product candidates. In addition, our previous clinical trials of eprenetapopt included cancer patients who were very sick and whose health was deteriorating, and we expect that additional clinical trials of eprenetapopt and our other product candidates would include similar patients with deteriorating health. Multiple patients in these trials have experienced adverse events. The most commonly reported adverse events include nausea, vomiting, constipation, dizziness, fatigue, and neutropenia. Some patients in these trials have experienced serious adverse events. The most common serious adverse events include febrile neutropenia, pneumonia, sepsis, and pyrexia.

We currently have no drugs approved for sale and we cannot guarantee that we will ever have marketable drugs. Clinical failure can occur at any stage of clinical development. Clinical trials may produce negative or inconclusive results, and we or any future collaborators may decide, or regulators may require us, to conduct additional clinical trials or preclinical studies. Additionally, with the current pause on further patient enrollment in both once daily and twice daily monotherapy dosing arms of ABOYA-119 and the orderly wind-down of certain clinical trial site activities associated with the monotherapy arms as we explore ATTN-119 in potential combination approaches, we may be unable to advance development of ATRN-119 for monotherapy in a timely manner, if at all. We will be required to demonstrate with substantial evidence through adequate and well-controlled clinical trials that our product candidates are safe and effective for use in treating specific conditions in order to obtain marketing approvals for their commercial sale. Success in preclinical studies and early-stage clinical trials does not mean that future larger registration clinical trials will be successful because product candidates in later-stage clinical trials may fail to demonstrate safety and efficacy to the satisfaction of the FDA and non-U.S. regulatory authorities despite having progressed through preclinical studies and early-stage clinical trials. Product candidates that have shown promising results in preclinical studies and early-stage clinical trials may still suffer significant setbacks in subsequent later-stage clinical trials. Additionally, the outcome of preclinical studies and early-stage clinical trials may not be predictive of the success of later-stage clinical trials. Further, in our oncology clinical trials to date, we have used achievement of stable disease as evidence for disease control (stable disease, partial response or complete response) by our product candidates; however, the FDA does not view stable disease as an objective response for the purposes of FDA approval. If we fail to receive positive results in clinical trials of our product candidates, the development timeline and regulatory approval and commercialization prospects for our most advanced product candidates, and, correspondingly, our business and financial prospects would be negatively impacted.

Before obtaining marketing approval from regulatory authorities for the sale of our product candidates, we must complete preclinical development and then conduct extensive clinical trials to demonstrate the safety and efficacy of our product candidates. Clinical testing is expensive, difficult to design and implement, can take many years to complete and is uncertain as to outcome. A failure of one or more clinical trials can occur at any stage of testing. The outcome of preclinical studies and early-stage clinical trials may not be predictive of the success of later clinical trials, and interim results of a clinical trial do not necessarily predict final results. Additionally, with the current pause on further patient enrollment in both once daily and twice daily monotherapy dosing arms of ABOYA-119 and the orderly wind-down of certain clinical trial site activities associated with the monotherapy arms as we explore ATTN-119 in potential combination approaches, we may be unable to advance development of ATRN-119 for monotherapy in a timely manner, if at all.

Because we have limited financial and managerial resources, we focus on research programs and product candidates that we identify for specific indications. As a result, we may forego or delay pursuit of opportunities with other product candidates or for other indications that later prove to have greater commercial potential. Our resource allocation decisions may cause us to fail to capitalize on viable commercial drugs or profitable market opportunities. Our spending on current and future research and development programs and product candidates for specific indications may not yield any commercially viable drugs. If we do not accurately evaluate the commercial potential or target market for a particular product candidate, we may relinquish valuable rights to that product candidate through collaboration, licensing or other strategic arrangements in cases in which it would have been more advantageous for us to retain sole development and commercialization rights to such product candidatecandidate.

The pharmaceutical and biotechnology industries generally, and the cancer drug sector specifically, are highly competitive and characterized by rapidly advancing technologies, evolving understanding of disease etiology and a strong emphasis on proprietary new drugs. We face competition with respect to APR-1051, ATRN-119 and our other product candidates, and will face competition with respect to any product candidates that we may seek to discover and develop or commercialize in the future, from major pharmaceutical, specialty pharmaceutical and biotechnology companies. There are a number of major pharmaceutical, specialty pharmaceutical and biotechnology companies that currently market and sell drugs or are pursuing the development of drugs for the treatment of cancer. Potential competitors also include academic institutions and governmental agencies and public and private research institutions.

We are also developing APR-1051, which is an orally bioavailable small molecule inhibitor of WEE1, a key regulator of multiple phases of the cell cycle. We are aware of other product candidates that are in preclinical and clinical development for the treatment of various cancers through similar mechanisms of action, including product candidates developed by Zentalis Pharmaceuticals, Debiopharm, IMPACT Therapeutics, Schrodinger and ZentalisAcrivon Pharmaceuticals,Therapeutics, among others. If APR-1051 were to be approved, it will compete with currently marketed drugs or drugs that may be approved for marketing by the FDA or comparable foreign regulatory authorities in the future and such competition will not be limited to drugs with similar mechanisms of action.

If we are successful at obtaining regulatory approval for APR-1051, ATRN-119ATRN-119, or any of our other product candidates, regulatory agencies in the United States and other countries where a product will be sold may require extensive additional clinical trials or post-approval clinical trials that are expensive and time-consuming to conduct. With the current pause on further patient enrollment in both once daily and twice daily monotherapy dosing arms of ABOYA-119 and the orderly wind-down of certain clinical trial site activities associated with the monotherapy arms as we explore ATTN-119 in potential combination approaches, we may be unable to advance development of ATRN-119 for monotherapy in a timely manner, if at all. These trials may reveal side effects or other harmful effects in patients that use our products after they are on the market, which may result in the limitation or withdrawal of our drugs from the market. Alternatively, we may not be able to conduct such additional trials, which might force us to abandon our efforts to develop or commercialize certain product candidates. Even if post-approval studies are not requested or required, after our products are approved and on the market, there might be safety issues that emerge over time that require a change in product labeling, additional post-market studies or clinical trials, imposition of distribution and use restrictions under a Risk Evaluation and Mitigation Strategy, or REMS, or withdrawal of the product from the market, which would cause our revenue to decline.

Our proprietary position for eprenetapopt depends upon patents that consist of method-of-use and formulation patent claims, which may not prevent a competitor or other third party from using the same product candidate for another use or in another formulation.

We have never obtained marketing approval for a product candidate. The time required to obtain approval by the FDA and comparable foreign regulatory authorities is unpredictable but typically takes many years following the commencement of preclinical studies and clinical trials and depends upon numerous factors, including the substantial discretion of the regulatory authorities. In addition, extraneous factors, including an epidemic or pandemic disease outbreak, or other public health situations, could impact the timeline for FDA and comparable foreign regulatory authorities to review an application for one of our product candidates. It is possible that the FDA and comparable foreign regulatory authorities may refuse to accept for filing and substantive review any new drug applications, or NDAs, marketing authorization applications, or MAA, that we submit for our product candidates or may conclude after review of our data that our application is insufficient to obtain marketing approval of our product candidates. If the FDA, or comparable foreign regulatory authorities do not accept or approve our NDAs or MAAs for our product candidates, it may require that we conduct additional clinical, nonclinical or manufacturing validation studies and submit that data before it will reconsider our applications. Depending on the extent of these or any other regulatory authority-required studies, approval of any NDA, MAA or other application that we submit may be delayed by several years, or may require us to expend more resources than we have available. It is also possible that additional studies, if performed and completed, may not be considered sufficient by the FDA or comparable foreign regulatory authorities to approve our NDAs or our MAAs. The current pause on further patient enrollment in both once daily and twice daily monotherapy dosing arms of ABOYA-119 and the orderly wind-down of certain clinical trial site activities associated with the monotherapy arms as we explore ATTN-119 in potential combination approaches, may further extend the time required to obtain approval by the FDA and comparable foreign regulatory authorities for ATRN-119.

This lengthy approval process as well as the unpredictability of clinical trial results may result in our failing to obtain marketing approval to market APR-1051 or ATRN-119, which would significantly harm our business, results of operations and prospects. Regulatory authorities have substantial discretion in the approval process and may refuse to accept any application or may decide that our data are insufficient for approval and require additional preclinical studies, clinical trials or other studies and testing. In addition, varying interpretations of the data obtained from preclinical studies and clinical trials could delay, limit or prevent marketing approval of a product candidate. Any marketing approval we, or any collaborators we may have in the future, ultimately obtain may be limited or subject to restrictions or post-approval commitments that render the approved drug not commercially viable.

We, or any future collaborators, may not be able to obtain or maintain orphan drug exclusivity for our product candidates and, even if we do, that exclusivity manymay not prevent the FDA or the European Commission from approving competing products.

Regulatory authorities in some jurisdictions, including the United States and the EU, may designate drugs for relatively small patient populations as orphan drugs. Under the Orphan Drug Act, the FDA may designate a product as an orphan drug if it is a drug intended to treat a rare disease or condition, which is generally defined as a patient population of fewer than 200,000 individuals annually in the United States, or a patient population greater than 200,000 in the United States where there is no reasonable expectation that the cost of developing the drug will be recovered from sales in the United States. Eprenetapopt has received orphan drug designation from the FDA for use in the treatment of high-risk myelodysplastic syndromes, or MDS, and orphan drug designation from the European Commission for MDS, AML, and ovarian cancer. We may seek orphan drug designations for eprenetapopt for other indications or for other of our product candidates. There can be no assurances that we will be able to obtain such designations.

We may seek a breakthrough therapy designation for ATRN-119APR-1051 or ATRN-119, or one or more of our other product candidates, but we might not receive such designation, and even if we do, such designation may not lead to a faster development or regulatory review or approval process.

We may seek a breakthrough therapy designation for APR-1051, ATRN-119 or one or more of our other product candidates. A breakthrough therapy is defined as a drug that is intended, alone or in combination with one or more other drugs, to treat a serious or life-threatening condition, and preliminary clinical evidence indicates that the drug may demonstrate substantial improvement over existing therapies on one or more clinically significant endpoints, such as substantial treatment effects observed early in clinical development. For drugs and biologics that have been designated as breakthrough therapies, interaction and communication between the FDA and the sponsor of the trial can help to identify the most efficient path for clinical development while minimizing the number of patients placed in ineffective control regimens. Drugs designated as breakthrough therapies by the FDA may also be eligible for priority review if supported by clinical data at the time the NDA is submitted to the FDA, and parts of the NDA may be submitted and reviewed on a rolling basis.

A fast track designation by the FDA for ATRN-119APR-1051, ATRN-119, or any of our other product candidates may not actually lead to a faster development or regulatory review or approval process.

Compliance with U.S. and international data protection laws and regulations could cause us to incur substantial costs or require us to change our business practices and compliance procedures in a manner adverse to our business. Moreover, complying with these various laws could require us to take on more onerous obligations in our contracts, restrict our ability to collect, use and disclose data, or in some cases, impact our ability to operate in certain jurisdictions. We have policies and procedures in place, and have conducted an independent third-party audit, to support our compliance with all applicable data protection laws and regulations, and are continually improving our data protection program to address compliance risks and evolving requirements. Nevertheless, our efforts to comply with data protection laws and evaluate as well as oversee our third party vendors’ compliance with data protection laws and our contractual requirements may be insufficient to mitigate all data protection risks or compliance obligations, which could result in regulatory scrutiny, legal liability, reputational risk or operational disruption. Failure by us or by our third-party vendors to comply with U.S. and international data protection laws and regulations could result in government enforcement actions (which could include civil or criminal penalties), private litigation and/or adverse publicity and could negatively affect our operating results and business. Claims that we or our third-party vendors have violated individuals’ privacy rights, failed to comply with data protection laws, or breached our contractual obligations, even if we or our third-party vendor, as applicable, are not found liable, could be expensive and time consuming to defend and could result in adverse publicity that could harm our business.

Relatedly, following the UK’s withdrawal from the EU (i.e., Brexit), the EU GDPR has been implemented in the United Kingdom (as the UK GDPR). The UK GDPR site alongside the UK Data Protection Act 2018 which implements certain derogations in the EU GDPR into UK law. The requirements of the UK GDPR are (at this time) largely aligned with those under the EU GDPR and as such, may lead to similar compliance and operational costs with potential fines for non-compliance of up to £17.5 million or 4% of annual worldwide turnover. As a result, we are potentially exposed to two parallel data protection regimes, each of which authorizes fines and the potential for divergent enforcement actions. It should also be noted that reliance on the new EU SCCs for transfers from the UK requires additional documentation in the form of a UK Addendum.

Moreover, our ability to use our net operating losses and other deferred tax assets to offset future taxable income in Sweden and the United States may be significantly limited if we experience an ownership change. For Swedish income tax purposes, an ownership change will generally occur when one, or several shareholders together, acquire shares representing more than 50 percent of the voting power over a five year period (under special provisions in Chapter 40 of the Swedish Income Tax Act; 1999:1229). Such an ownership change results in the forfeiture of tax losses carried forward exceeding 200 percent of the cost of the change of control. In this calculation, capital contributions to the company prior to the ownership change and in the preceding two years should reduce the cost of the change of control. Due to potential ownership changes under the Swedish Income Tax Act, we may be limited in our ability to realize a tax benefit on our deferred tax assets, whether or not we attain profitability in future years.

Sales of a substantial number of shares of our common stock in the public market could occur at any time. These sales, or the perception in the market that the holders of a large number of shares intend to sell shares, could reduce the market price of our common stock. As of December 31, 2024, we had outstanding 5,481,055 shares of common stock. In addition, 28,112 shares of common stock are issuable upon the conversion of preferred stock.

WeIf arewe requiredfail to meetregain compliance with the continuedminimum listingbid requirementsprice ofrequirement Nasdaq andor other Nasdaq rules, including those regarding director independence and independent committee requirements, minimum stockholders’ equity, minimum share price and certain other corporate governance requirements. If we do not meet these continued listing requirements,standards, our common stock couldwill be delisted.subject to delisting. Delisting from Nasdaq could adversely affect our ability to raise additional financing through the public or private sale of equity securities, would significantly affect the ability of investors to trade our securities and would negatively affect the value and liquidity of our common stock. Delisting could also have other negative results, including the potential loss of confidence by employees, the loss of institutional investor interest and fewer business development opportunities. Delisting could also cause us to pursue eligibility for trading of these securities on other markets or exchanges, including the OTC BB or QB markets, or on the OTC “pink sheets.” In such case, our stockholders’ ability to trade, or obtain quotations of the market value of our common stock would be severely limited because of lower trading volumes and transaction delays. These factors could contribute to lower prices and larger spreads in the bid and ask prices of our securities. There can be no assurance that our securities, if delisted from the Nasdaq Capital Market in the future, would be listed on a national securities exchange, a national quotation service, the OTC markets or the pink sheets. Delisting from Nasdaq, or even the issuance of a notice of potential delisting,Nasdaq would also result in negative publicity, make it more difficult for us to raise additional capital, cause us to lose eligibility to register the sale or resale of our shares on Form S-3 and the automatic exemption from registration under state securities laws for exchange-listed securities, adversely affect the market liquidity of our securities, decrease securities analysts’ coverage of us or diminish investor, supplier and employee confidence.

We are a clinical-stage biopharmaceutical company focused on precision oncology through synthetic lethality. Prior to the acquisition of Atrin Pharmaceuticals Inc. (“Atrin”) in May 2022, we were engaged in the clinical development of cancer therapeutics that reactivate the mutant p53 tumor suppressor protein. Following our acquisition of Atrin, we shifted the focus of our activities to the assets acquired from Atrin. Our approach is built upon a platform of integrated discovery technologies to enrich our pipeline with novel targets in synthetic lethality and cancer treatment. Together with our expertise in small molecule drug discovery, we are applying the capabilities of our discovery platform to the development of new precision oncology therapies and the identification of patient populations most likely to benefit.

In addition, we also have an early preclinical researchearly-stage program, whichAPR-1602, isa currentlymacrocyclic DYRK1A/B inhibitor, that will be ready to enter IND-enabling studies in the leadfourth optimizationquarter stage,of for an undisclosed DDR target.2026. We do not currently have any ongoing preclinical studies or clinical trials involving our reactivators of mutant p53 and our primary focus is on the discovery and development of molecules targeting DDR pathways in oncology through synthetic lethality.

We have devoted substantially all of our resources to developing our product candidates, building our intellectual property portfolio, business planning, raising capital and providing general and administrative support for these operations. To date, we have financed our operations primarily through the net proceeds received from the initial public offering of our common stock and sales of common stock through public and private offerings.

As a result, we will need additional financing to support our continuing operations. Until such time as we can generate significant revenue from product sales, if ever, we expect to finance our operations through a combination of public or private equity or debt financings or other sources, which may include collaborations with third parties.parties and grants from government and other (non-government) organizations. We may be unable to raise additional funds or enter into other agreements or arrangements when needed on favorable terms, or at all. If we fail to raise capital or enter into such agreements as and when needed, we may have to significantly delay, scale back or discontinue the development or commercialization of one or more of our product candidates. In addition, our ability to engage in certain types of capital raising transactions may be limited by the Listing Rules of the Nasdaq Stock Market and/or General Instruction I.B.6 of Form S-3 if the market value of our common stock held by non-affiliates is ever below $75 million at a time we seek to utilize our effective registration statement on Form S-3.

As of December 31, 2024,2025, we had cash and cash equivalents of $22.8$14.6 million. We believe that our existing cash and cash equivalents as of December 31, 20242025 and the gross proceeds of approximately $5.6 million received from our private placement of our common stock and warrants in January 2026, before deducting placement agent fees and offering costs of approximately $0.4 million, will be sufficient to meet our currently projected operating expenses and capital expenditure requirements into the first quarter of 2026.2027. We have based this estimate on assumptions that may prove to be wrong, and we could exhaust our available capital resources sooner than we expect. See “—Liquidity and Capital Resources.” We have concluded that substantial doubt exists about our ability to continue as a going concern for a period of at least 12 months from the date of the issuance of these audited consolidated financial statements.

Our revenue is primarily generated through grants from government and non-government organizations. Grant revenue is recognized during the period that the research and development services occur, as qualifying expenses are incurred or conditions of the grants are met. Associated expenses are recognized when incurred as research and development expense. We concluded that payments received under these grants represent conditional, nonreciprocal contributions, as described in ASC 958, Not-for-Profit Entities, and that the grants are not within the scope of ASC 606, Revenue from Contracts with Customers, as the organizations providing the grants do not meet the definition of a customer.

Research and development activities are central to our business model. Product candidates in later stages of clinical development generally have higher development costs than those in earlier stages of clinical development, primarily due to the increased size and duration of later-stage clinical trials. We expect that our research and development expenses will continue to increase for the foreseeable future as we initiateprogress clinical trials for ATRN-119APR-1051. With the current pause on further patient enrollment in both once daily and othertwice productdaily candidatesmonotherapy dosing arms of ABOYA-119 and continuethe orderly wind-down of certain clinical trial site activities associated with the monotherapy arms as we explore ATTN-119 in potential combination approaches, we may be unable to discoveradvance anddevelopment developof additionalATRN-119 productfor candidates.monotherapy in a timely manner, if at all.

Interest income consists of income earned on our cash and cash equivalents. Interest expense consists of the interest component associated with our facility leases. Our interest income initially increased as our cash and cash equivalents were higher due to the cash proceeds received from our IPO. Such interest income is subsequently decreasing as (i) our cash balance decreases as we continue to fund operations and (ii) a change in interest rates.

Grant revenue from the National Cancer Institute of the National Institutes of Health (“NIH”) for the years ended December 31, 20242025 and 20232024 was approximately $1.5$0.3 million and $0.6$1.5 million, respectively. The decrease in grant revenue of $1.2 million is due to recognizing less grant revenue from the NIH.

Research and development expenses for the year ended December 31, 20242025 were $9.4$7.0 million, compared to $7.6$9.4 million for the year ended December 31, 2023.2024. The overall increasedecrease of $1.7$2.3 million was primarily due to the following:

General and administrative expenses for the year ended December 31, 20242025 were $6.5 million, compared to $8.4$6.5 million for the year ended December 31, 2023. The decrease of $2.0 million was primarily related to:2024.

Foreign currency loss was $95,319 for the year ended December 31, 2025 compared to a foreign currency gain wasof $71,800 for the year ended December 31, 2024 compared to a foreign currency loss of $38,926 for the year ended December 31, 2023.2024. The change in the foreign currency of $110,726$167,119 was primarily due to a strengtheningweakening of the U.S. dollar against the Swedish Krona during the year ended December 31, 20242025 as compared to the year ended December 31, 2023.2024. Other income was $77,500 for the year ended December 31, 2025 and was related to the monetization of a portion of the Company’s state net operating loss carryforwards. Interest income for the years ended December 31, 2025 and 2024 primarily consisted of interest earned on our cash and cash equivalents.

Since our inception, we have incurred significant losses on an aggregate basis. We have not yet commercialized any of our product candidates, which are in various phases of preclinical and clinical development, and we do not expect to generate revenue from sales of any products for several years, if at all. Our ability to generate product revenue sufficient to achieve profitability will depend on the successful development and eventual commercialization of one or more of our product candidates. Since 2019, our primary source of funds has been from the public and private sales of our common stock. As of December 31, 2024,2025, we had cash and cash equivalents of $22.8$14.6 million. We believe that our existing cash and cash equivalents as of December 31, 20242025, together with the capital raised in our January 2026 private placement financing, will be sufficient to meet our currently projected operating expenses and capital expenditure requirements into the first quarter of 2026.2027. We have concluded that substantial doubt exists about our ability to continue as a going concern for a period of at least 12 months from the date of the issuance of these audited consolidated financial statements.

On November 8, 2024, we entered into an At the Market Offering Agreement, or the 2024 ATM Agreement, with H.C. Wainright & Co., LLC, or HCW. Pursuant to the 2024 ATM Agreement and the prospectus supplement filed in connection therewith, we may, from time to time, in our sole discretion, issue and sell through HCW, acting as sales agent and/or principal, up to $3.0 million of shares of our common stock. During the year ended year ended December 31, 2025, we issued and sold 1,337,948 shares of common stock under the Sales Agreement resulting in net proceeds of approximately $1.9 million. During the year ended December 31, 2024, we issued and sold 41,152 shares of common stock under the Sales Agreement resulting in net proceeds of approximately $0.1 million.

Cash used in operating activities resulted primarily from our net losses adjusted for non-cash charges and changes in components of working capital. Net cash used in operating activities was $12.9 million for the year ended December 31, 2025 compared to $13.6 million for the year ended December 31, 2024 compared to $12.2 million for the year ended December 31, 2023.2024. The increasedecrease in net cash used in operating activities of $1.4$0.7 million was primarily attributable to a change in operating assets and liabilities of $2.7$0.1 million, partially offset by a decrease in our net loss of $0.8$0.4 million.

No cash was used in or provided by investing activities for the year ended December 31, 2025. Cash used in investing activities for the yearsyear ended December 31, 2024 andof 2023$15,478 was $15,478 and $93,093, respectively. Cash used in investing activities representedfor the acquisitionpurchase of property and equipment.

As of December 31, 2024,2025, we had cash and cash equivalents of $22.8$14.6 million. We believe that our existing cash and cash equivalents as of the year ended December 31, 20242025 and the gross proceeds of approximately $5.6 million received from our private placement of our common stock and warrants in January 2026, before deducting placement agent fees and offering costs of approximately $0.4 million, will be sufficient to meet our currently projected operating expenses and capital expenditure requirements into the first quarter of 2026.2027. We have based this estimate on assumptions that may prove to be wrong, and we could exhaust our available capital resources sooner than we expect. We have concluded that substantial doubt exists about our ability to continue as a going concern for a period of at least 12 months from the date of the issuance of these audited consolidated financial statements.

Since our inception, we have incurred significant losses on an aggregate basis. Our net loss was $3.3$6.9 million for the threesix months ended MarchJune 31,30, 2026, and $12.6 million and $13.0 million for the years ended December 31, 2025 and 2024, respectively. Our accumulated deficit was $336.9$340.5 million and $333.6 million as of MarchJune 31,30, 2026 and December 31, 2025, respectively. We have not generated any commercial revenue to date from sales of any drugs and have financed our operations principally through private placements and the net proceeds received from the initial public offering (IPO) of our common stock. We have devoted substantially all of our efforts to research and development. We expect that it will be several years, if ever, before we have any product candidates ready for commercialization. We expect to continue to incur significant expenses and increasing operating losses for the foreseeable future. The net losses we incur may fluctuate significantly from quarter to quarter.

Our limited operating history may make it difficult for you to evaluate the success of our business to date and to assess our future viability. We have never generated commercial revenues and may never be profitable.*

We are an early-stage company. Our operations to date have been limited to organizing and staffing our company, business planning, raising capital, developing our product candidates, identifying potential product candidates, conducting preclinical studies of our product candidates and conducting clinical trials of our product candidates. APR-1051 and ATRN-119,ATRN-119 are in clinical development and our other product candidates are in preclinical development. We have currently paused further patient enrollment in both the once daily and twice daily monotherapy dosing arms of ABOYA-119 and started the orderly wind-down of certain clinical trial site activities associated with the monotherapy arms as we explore ATRN-119 in potential combination approaches. We have not yet demonstrated our ability to successfully complete large-scale, pivotal clinical trials, obtain marketing approvals, manufacture commercial-scale drug products, or arrange for a third party to do so on our behalf, or conduct sales and marketing activities necessary for successful drug commercialization. Typically, it takes about six to ten years to develop a new drug from the time it is in Phase 1 clinical trials to when it is approved for treating patients, but in many cases it may take longer. Consequently, any predictions you make about our future success or viability may not be as accurate as they could be if we had a longer operating history.

Based on our current operating plan, we believe that our existing cash and cash equivalents as of MarchJune 31,30, 2026 will be sufficient to meet our currently projected operating expenses and capital expenditure requirements into the first quarter of 2028. Our estimate as to how long we expect our existing cash and cash equivalents to be able to continue to fund our operations is based on assumptions that may prove to be wrong, and we could use our available capital resources sooner than we currently expect. Further, changing circumstances, some of which may be beyond our control, could cause us to consume capital significantly faster than we currently anticipate, and we may need to seek additional funds sooner than planned. Our future capital requirements will depend on many factors, including:

We are currently operating in a period of global economic uncertainty and capital markets disruption, which has been significantly impacted by geopolitical conflicts, natural and man-made disasters, global health emergencies and uncertainties in regulatory developments and legislative actions, which could adversely affect our business, financial condition and results of operations.*

Changes in regulations and policies by the U.S. administration and the resulting political and economic uncertainty in the United States may also impact us, the financial markets and the global economy. ForIn example,2025, significant changes in AprilU.S. 2025,trade increasedpolicy, tariffs were imposed on all countries and individualized “reciprocal” higher tariffs on certain countries with whichincluding the Unitedimposition Statesof hasbroad the largest trade deficits, with the highestbased tariffs imposed on imports from China.multiple Chinacountries, created uncertainty in global supply chains that could affect our ability to source clinical trial materials and othercould countriesincrease respondedour byoperating announcing retaliatory tariffs on U.S. imports. A few days later, the tariffs imposed on most countries were reduced to 10 percent, with the exception of China, for a period of 90 days to allow trade negotiations with those countries. It is unclear whether the tariff increases with China will continue to escalate.costs. The tariff increases have significantly disrupted the global markets and may significantly escalate tensions between the U.S. and other countries, especially China. We currently procure APIs and other raw materials from a supplier in ChinaChina, .and we are in the process of diversifying our API procurement to include additional suppliers in the United States. The extent of the impact that such tariffs, trade policies, or new legislation or regulations will have on our business specifically, or on the U.S. market and global economy generally, are uncertain and in the long term, unpredictable, and could adversely affect our business, financial condition, and results of operations. The continued impact of these tariffs may impair our plans for further drug development in the U.S. market as well as our ability to generate revenues.

We are substantially dependent on the success of APR-1051 and ATRN-119.APR-1051. Our clinical trials of APR-1051 and ATRN-119 may not be successful. If we are unable to obtain approval for and commercialize APR-1051 and ATRN-119 or experience significant delays in doing so, our business will be materially harmed.

We have no products approved for sale. Our future success is substantially dependent on our ability to timely obtain marketing approval for, and then successfully commercialize, APR-1051 and ATRN-119.APR-1051. We are investing a majority of our efforts and financial resources in the research and development of APR-1051 and ATRN-119.APR-1051. Our business depends entirely on the successful development and commercialization of our product candidates. We currently have no drugs approved for sale and generate no revenues from sales of any products, and we may never be able to develop a marketable product.

The success of APR-1051 and ATRN-119 will depend on several factors, including the following:

We are in the early stages of testing APR-1051 and ATRN-119 in Phase 1 clinical trials and we have not tested APR-1051 or ATRN-119 in later phase clinical trials. The results of preclinical studies and early-stage clinical trials may not be predictive of future results in later studies or trials. Initial success in clinical trials may not be indicative of results obtained when these trials are completed or in later-stage clinical trials.

We are in the early stages of testing APR-1051 and ATRN-119 in clinical trials and we have not tested APR-1051 or ATRN-119 in later phase clinical trials. The results of preclinical studies, whether or not conducted by us, may not be predictive of the results of clinical trials, and the results of the early-stage clinical trials that we are conducting today and that we may commence in the future may not be predictive of the results of the later-phase clinical trials. For example, even if successful, the results of our Phase 1 clinical trials of our product candidates APR-1051 and ATRN-119 and other product candidates may not be predictive of the results of further clinical trials of these product candidates or any of our other product candidates. In addition, initial success in clinical trials may not be indicative of results obtained when such trials are completed or in later stage clinical trials. In particular, the small number of patients in our current and planned early clinical trials may make the results of these trials less predictive of the outcome of later clinical trials. Moreover, preclinical and clinical data often are susceptible to varying interpretations and analyses, and many companies that have believed their product candidates performed satisfactorily in preclinical studies and clinical trials nonetheless have failed to obtain marketing licensure of their product candidates. Our current and future clinical trials for APR-1051 and ATRN-119 may not ultimately be successful or support further clinical development. There is a high failure rate for product candidates proceeding through clinical trials. In addition, with the current orderly wind-downclosure of ABOYA-119 study as we explore ATRN-119 in potential combination approaches, we may be unable to advance development of ATRN-119 in a timely manner, if at all. Many companies in the pharmaceutical and biotechnology industries have suffered significant setbacks in clinical development even after achieving encouraging results in earlier studies. Any such setbacks in our clinical development could materially harm our business, results of operations, financial condition and prospects.

We have limited experience as a company conducting clinical trials and may be unable to complete pivotal clinical trials for any product candidates we may develop.*

While we have assembled a team with extensive experience in the discovery, development, and commercialization of oncology drugs to support our mission of developing novel synthetic lethality-based cancer therapeutics, we have limited experience designing, conducting and enrolling subjects in clinical trials. While certain members of our management and staff have significant experience in conducting clinical trials, to date, we have not completed any clinical trials as a company. Our operations to date provide a limited basis to assess our ability to develop and commercialize our product candidates. In addition, with the current orderly wind-downclosure of the ABOYA-119 study as we explore ATRN-119 in potential combination approaches, we may be unable to advance development of ATRN-119 in a timely manner, if at all.

We may find it difficult to enroll patients in our clinical trials. If we experience delays or difficulties in the enrollment of patients in clinical trials, our receipt of necessary marketing approvals could be delayed or prevented.*

Aside from PARP inhibitors, such as Lynparza, Rubraca, Zejula and Talzenna, no synthetic lethality small molecule inhibitor therapeutics have been approved to date by the FDA. Pamiparib, a PARP inhibitor developed by Beigene, was approved in 2021 in China. Adverse events in future clinical trials of our product candidates or in clinical trials of other similar products and the resulting publicity, as well as any other adverse events in the field of synthetic lethality and DDR, or any adverse events involving other products that are perceived to be similar to DDR, such as those related to immuno-oncology, antibody-drug conjugant, gene therapy or gene editing, could result in a decrease in the perceived benefit of one or more of our programs, increased regulatory scrutiny, decreased confidence by healthcare professionals, patients and CROs in our product candidates, difficulties and delays in regulatory clearance or approval for, enrollment of patients in, and conduct of, our clinical trials, and less demand for any product that we may develop. Our pipeline of product candidates could experience a greater quantity of reportable adverse events or other reportable negative clinical outcomes, manufacturing reportable events or material clinical events that could lead to clinical delays or holds by the FDA or applicable regulatory authority or other clinical delays, any of which could negatively impact the perception of one or more of our product development programs, as well as our business as a whole.

If serious adverse or unacceptable side effects are identified during the development of our product candidates or we observe limited efficacy of our product candidates, we may need to abandon or limit the development of one or more of our product candidates.*

In general, our clinical trials of APR-1051 and ATRN-119 will or currently include cancer patients who are very sick and whose health is deteriorating. We expect that patients may experience adverse events, serious adverse events or may die during their participation in our current or future clinical trials for APR-1051 and ATRN-119 or other product candidates. We cannot predict with certainty what adverse events may occur in our clinical trials. Any adverse events, serious adverse events, or deaths occurring in our clinical trials, whether related to our product candidates or not, could affect perceptions relating to our product candidates. In addition, our previous clinical trials of eprenetapopt included cancer patients who were very sick and whose health was deteriorating, and we expect that additional clinical trials of eprenetapopt and our other product candidates would include similar patients with deteriorating health. Multiple patients in the eprenetapopt trials have experienced adverse events. The most commonly reported adverse events include nausea, vomiting, constipation, dizziness, fatigue, and neutropenia. Some patients in these trials have experienced serious adverse events. The most common serious adverse events include febrile neutropenia, pneumonia, sepsis, and pyrexia.

The outcome of preclinical testing and early clinical trials may not be predictive of the success of later clinical trials, interim results of a clinical trial do not necessarily predict final results, and the results of our clinical trials may not satisfy the requirements of the FDA or comparable foreign regulatory authorities.*

We currently have no drugs approved for sale and we cannot guarantee that we will ever have marketable drugs. Clinical failure can occur at any stage of clinical development. Clinical trials may produce negative or inconclusive results, and we or any future collaborators may decide, or regulators may require us, to conduct additional clinical trials or preclinical studies. Additionally, with the current orderly wind-down of the ABOYA-119 study as we explore ATRN-119 in potential combination approaches, we may be unable to advance development of ATRN-119 in a timely manner, if at all. We will be required to demonstrate with substantial evidence through adequate and well-controlled clinical trials that our product candidates are safe and effective for use in treating specific conditions in order to obtain marketing approvals for their commercial sale. Success in preclinical studies and early-stage clinical trials does not mean that future larger registration clinical trials will be successful because product candidates in later-stage clinical trials may fail to demonstrate safety and efficacy to the satisfaction of the FDA and non-U.S. regulatory authorities despite having progressed through preclinical studies and early-stage clinical trials. Product candidates that have shown promising results in preclinical studies and early-stage clinical trials may still suffer significant setbacks in subsequent later-stage clinical trials. Additionally, the outcome of preclinical studies and early-stage clinical trials may not be predictive of the success of later-stage clinical trials. Further, in our oncology clinical trials to date, we have used achievement of stable disease as evidence for disease control (stable disease, partial response or complete response) by our product candidates; however, the FDA does not view stable disease as an objective response for the purposes of FDA approval. If we fail to receive positive results in clinical trials of our product candidates, the development timeline and regulatory approval and commercialization prospects for our most advanced product candidates, and, correspondingly, our business and financial prospects would be negatively impacted.

In addition, in the event that a safety issue, clinical hold, or other adverse finding occurs in one of our clinical trials, that event could adversely affect any other clinical trials for the same product candidate. Moreover, there is a relatively limited safety data set for product candidates with the same mechanism of action as APR-1051, ATRN-119 or our other product candidates. An adverse safety issue or other adverse finding in a clinical trial conducted by a third party with a similar mechanism of action could adversely affect clinical trials involving APR-1051, ATRN-119APR-1051 or our other product candidates.

Clinical drug development is a lengthy and expensive process, with an uncertain outcome. If clinical trials of our product candidates fail to demonstrate safety and efficacy to the satisfaction of regulatory authorities or do not otherwise produce positive results, we may incur additional costs, experience delays in completing, or ultimately be unable to complete, the development of our product candidates or be unable to obtain marketing approval.*

Before obtaining marketing approval from regulatory authorities for the sale of our product candidates, we must complete preclinical development and then conduct extensive clinical trials to demonstrate the safety and efficacy of our product candidates. Clinical testing is expensive, difficult to design and implement, can take many years to complete and is uncertain as to outcome. A failure of one or more clinical trials can occur at any stage of testing. The outcome of preclinical studies and early-stage clinical trials may not be predictive of the success of later clinical trials, and interim results of a clinical trial do not necessarily predict final results. Additionally, with the current orderly wind-down of the ABOYA-119 study as we explore ATRN-119 in potential combination approaches, we may be unable to advance development of ATRN-119 in a timely manner, if at all.

We face substantial competition, which may result in others discovering, developing or commercializing products before or more successfully than we do.*

If we are successful at obtaining regulatory approval for APR-1051, ATRN-119APR-1051 or any of our other product candidates, regulatory agencies in the United States and other countries where a product will be sold may require extensive additional clinical trials or post-approval clinical trials that are expensive and time-consuming to conduct. With the current pause on further patient enrollment in both once daily and twice daily monotherapy dosing arms of ABOYA-119 and the orderly wind-down of certain clinical trial site activities associated with the monotherapy arms as we explore ATRN-119 in potential combination approaches, we may be unable to advance development of ATRN-119 for monotherapy in a timely manner, if at all. TheseClinical trials may reveal side effects or other harmful effects in patients that use our products after they are on the market, which may result in the limitation or withdrawal of our drugs from the market. Alternatively, we may not be able to conduct such additional trials, which might force us to abandon our efforts to develop or commercialize certain product candidates. Even if post-approval studies are not requested or required, after our products are approved and on the market, there might be safety issues that emerge over time that require a change in product labeling, additional post-market studies or clinical trials, imposition of distribution and use restrictions under a Risk Evaluation and Mitigation Strategy, or REMS, or withdrawal of the product from the market, which would cause our revenue to decline.

We have never obtained marketing approval for a product candidate and we may be unable to obtain, or may be delayed in obtaining, marketing approval for any of our product candidates.*

We have never obtained marketing approval for a product candidate. The time required to obtain approval by the FDA and comparable foreign regulatory authorities is unpredictable but typically takes many years following the commencement of preclinical studies and clinical trials and depends upon numerous factors, including the substantial discretion of the regulatory authorities. In addition, extraneous factors, including an epidemic or pandemic disease outbreak, or other public health situations, could impact the timeline for FDA and comparable foreign regulatory authorities to review an application for one of our product candidates. It is possible that the FDA and comparable foreign regulatory authorities may refuse to accept for filing and substantive review any new drug applications, or NDAs, marketing authorization applications, or MAA, that we submit for our product candidates or may conclude after review of our data that our application is insufficient to obtain marketing approval of our product candidates. If the FDA, or comparable foreign regulatory authorities do not accept or approve our NDAs or MAAs for our product candidates, it may require that we conduct additional clinical, nonclinical or manufacturing validation studies and submit that data before it will reconsider our applications. Depending on the extent of these or any other regulatory authority-required studies, approval of any NDA, MAA or other application that we submit may be delayed by several years, or may require us to expend more resources than we have available. It is also possible that additional studies, if performed and completed, may not be considered sufficient by the FDA or comparable foreign regulatory authorities to approve our NDAs or our MAAs. The current orderly wind-down of the ABOYA-119 study as we explore ATRN-119 in potential combination approaches, may further extend the time required to obtain approval by the FDA and comparable foreign regulatory authorities for ATRN-119.

Even if we complete the necessary preclinical studies and clinical trials, the marketing approval process is expensive, time-consuming and uncertain and may prevent us, or any future collaborators, from obtaining approvals for the commercialization of some or all of our product candidates. As a result, we cannot predict when or if, and in which territories, we, or any future collaborators, will obtain marketing approval to commercialize a product candidate.*

This lengthy approval process as well as the unpredictability of clinical trial results may result in our failing to obtain marketing approval to market APR-1051 or ATRN-119,APR-1051, which would significantly harm our business, results of operations and prospects. Regulatory authorities have substantial discretion in the approval process and may refuse to accept any application or may decide that our data are insufficient for approval and require additional preclinical studies, clinical trials or other studies and testing. In addition, varying interpretations of the data obtained from preclinical studies and clinical trials could delay, limit or prevent marketing approval of a product candidate. Any marketing approval we, or any collaborators we may have in the future, ultimately obtain may be limited or subject to restrictions or post-approval commitments that render the approved drug not commercially viable.

As of MarchJune 31,30, 2026, our executive officers and directors and our stockholders which own more than 5% of our outstanding common stock beneficially owned shares representing approximately 33.4%20.3% of our common stock. As a result, if these stockholders were to choose to act together, they may have substantial influence over matters submitted to our stockholders for approval, as well as our management and affairs. For example, these persons, if they choose to act together, would control the election of directors and approval of any merger, consolidation or sale of all or substantially all of our assets. This concentration of voting power could delay or prevent an acquisition of our company, or other significant corporate decisions, on terms that other stockholders may desire.

As of January 1, 2025, we are no longer an “emerging growth company,” as defined in the Jumpstart Our Business Act of 2012, of the JOBS Act. However, we remain a “smaller reporting company,” as such term is defined in Rule 12b-2 of the Exchange Act, meaning that the market value of our common stock held by non-affiliates is less than $700 million and our annual revenue is less than $100 million during the most recently completed fiscal year. We maywill continue to be a smaller reporting company if either (i) the market value of our common stock held by non-affiliates is less than $250 million or (ii) our annual revenue is less than $100 million during the most recently completed fiscal year and the market value of our common stock held by non-affiliates is less than $700 million. As a smaller reporting company, we may continue to rely on exemptions from certain disclosure requirements that are available to smaller reporting companies. Specifically, as a smaller reporting company we may choose to present only the two most recent fiscal years of audited financial statements in our Annual Report on Form 10-K and smaller reporting companies have reduced disclosure obligations regarding executive compensation.

Accounting principles and related pronouncements, implementation guidelines and interpretations we apply to a wide range of matters that are relevant to our business, including, but not limited to, revenue recognition, leases and stock-based compensation, are complex and involve subjective assumptions, estimates and judgments by our management. Changes in accounting pronouncements or their interpretation or changes in underlying assumptions, estimates or judgments by our management could significantly change our reported or expected financial performance.

We are required to meet the Nasdaq Stock Market, or Nasdaq, continued listing requirements and other Nasdaq rules, and if we fail to meet such rules and requirements, we may be subject to delisting. Delisting could negatively affect the price of our common stock, which could make it more difficult for us to sell securities in a future financing or for you to sell our common stock.*

The continued listing standards of Nasdaq applicable to the Nasdaq Capital Market require, among other things, that the minimum price of a listed company’s stock be at or above $1.00. If the minimum bid price is below $1.00 for a period of more than 30 consecutive trading days, the listed company will fail to be in compliance with Nasdaq’s listing rules and, if the listed company does not regain compliance within a 180-day grace period, it may be subject to delisting. In order to regain compliance, the bid price of the listed company’s common stock must close at a price of at least $1.00 per share for a minimum of 10 consecutive trading days within a 180-day grace period. In addition, in July 2026 Nasdaq approved a new rule requiring listed companies to maintain a minimum market value of listed securities (MVLS) of $5 million. If our MLVS falls below this threshold for 30 consecutive business days, we may be subject to delisting proceedings. On January 23, 2026, we received a deficiency letter from Nasdaq notifying us that, for the last 30 consecutive business days, the closing bid price for our common stock was below the minimum $1.00 per share required for continued listing on The Nasdaq Capital Market pursuant to Nasdaq Listing Rule 5550(a)(2). The letter also indicated that, pursuant to Nasdaq Listing Rule 5810(c)(3)(A), we would be afforded 180 calendar days to regain compliance with the bid price requirement. On July 23, 2026, we received a notification letter from Nasdaq informing us that we are eligible for an additional 180 calendar day period, or until January 19, 2027 to regain compliance with the minimum bid price requirement. There can be no assurance that we will regain compliance with the minimum bid price requirement (or, if we do so, that we will maintain compliance with the minimum bid price requirement or any other Nasdaq listing standards.standards).

If we fail to regain compliance with the minimum bid price requirement, the MLVS requirement or other Nasdaq listing standards, our common stock will be subject to delisting. Delisting from Nasdaq could adversely affect our ability to raise additional financing through the public or private sale of equity securities, would significantly affect the ability of investors to trade our securities and would negatively affect the value and liquidity of our common stock. Delisting could also have other negative results, including the potential loss of confidence by employees, the loss of institutional investor interest and fewer business development opportunities. Delisting could also cause us to pursue eligibility for trading of securities on other markets or exchanges, including the OTC BB or QB markets, or on the OTC “pink sheets.” In such case, our stockholders’ ability to trade, or obtain quotations of the market value of our common stock would be severely limited because of lower trading volumes and transaction delays. These factors could contribute to lower prices and larger spreads in the bid and ask prices of our securities. There can be no assurance that our securities, if delisted from the Nasdaq Capital Market in the future, would be listed on a national securities exchange, a national quotation service, the OTC markets or the pink sheets. Delisting from Nasdaq would also result in negative publicity, make it more difficult for us to raise additional capital, cause us to lose eligibility to register the sale or resale of our shares on Form S-3 and the automatic exemption from registration under state securities laws for exchange-listed securities, adversely affect the market liquidity of our securities, decrease securities analysts’ coverage of us or diminish investor, supplier and employee confidence.

We are targeting WEE1, a kinase that is a key regulator of multiple phases of the cell cycle. Our lead WEE1 inhibitor product candidate is APR-1051. In March 2024, our IND for APR-1051 (IND 169359) went into effect and in the second quarter of 2024 we enrolled the first patient into ACESOT-1051, our Phase 1 dose escalation study. Preliminary results provide early clinical proof-of-concept of APR-1051. A potential dose-response trend was observed, with increasing single-agent activity across the 70 mg, 100 mg, 150 mg and 220 mg cohorts. On January 29, 2026, we announced the first unconfirmed partial response (uPR) observed in a patient enrolled in the ongoing Phase 1 ACESOT-1051 dose-escalation study: a patient with PPP2R1A-mutated uterine serous carcinoma, a form of endometrial cancer, treated at the 150 mg dose level of APR-1051. At the protocol-defined 8-week first imaging assessment, the patient achieved a 50% reduction in target lesion size per RECIST v1.1 criteria, along with a marked reduction in cancer antigen 125 (CA-125) levels, from 732 to 70 U/mL. CA-125 is a well-recognized tumor marker in endometrial cancer. On March 30, 2026, we announced a confirmed partial response observed in a second patient with PPP2R1A-mutated endometrial cancer, treated at the 220 mg dose level. At the first imaging assessment the patient achieved a 50% reduction in target lesion size, along with a marked decline in CA-125 from 362 at baseline to 47 U/mL, further supporting the anti-tumor activity of APR-1051. This response was subsequently confirmed at the second image assessment, with an additional 9.5% reduction in target lesion size, and a reduction in CA-125 to 40.2U/ml (from 362 U/mL at baseline). As of AprilMay 30,6, 2026, we observed 6 patients with stable disease in the ongoing Phase 1 ACESOT-1051 dose escalation study. InWe addition,expect preliminaryto resultsreport the next clinical data update from the ACESOT-1051 study indicate that APR-1051 has been well-tolerated to date, supporting our development strategy to differentiate WEE1 inhibition throughat a potentiallymedical improved therapeutic index. We are currently dosing patientsmeeting in the 300mgfourth cohort.quarter Ifof 2026. Enrollment is accelerating ahead of this anticipated clinical catalyst, with the 300mgnumber cohortof isactive deemedclinical safesites weexpanding planfrom three to furtherten. doseWe expect enrollment to reach 6 to 10 patients atper 400mgmonth andby willQ4 furtherof test2026, atpotentially 500mg, if 400mg is deemed safe. We will enroll subjects into backfill at 220mg afterincreasing the 300mg cohort is fully enrolled. Backfill consistspace of assigningclinical patientsdata to dose levels below the level where the study is at and allows for the collection of additional pharmacokinetic, and response data.generation. Our plan is to expand enrollment in ACESOT-1051 to include at least 50 patients with uterine serous carcinoma (USC), as well asor patients with cyclin E-overexpressing, platinum-resistant ovarian cancer (PROC). This strategy is designed to sharpen the clinical development path for APR-1051 and provide further insight into biomarker-defined patient populations most likely to benefit from WEE1 inhibition. WeCompletion anticipateof open-labeldose safety/efficacy data to be available throughout 2026escalation and expectbackfill toexpansion completeis dose-escalationanticipated in the second quarter of 2027.

Our second clinical-stage synthetic lethality product candidate is ATRN-119, an oral small molecule inhibitor of ataxia telangiectasia and Rad3-related, or ATR. The ATR kinase is a master regulator of the DNA damage response, with key roles in cell cycle control and DNA repair following replication stress. We have developed ATRN-119, the first oral macrocyclic ATR inhibitor to enter clinical trials. On October 15, 2025, we determined the recommended Phase 2 monotherapy dose (RP2D) of 1,100 mg once daily for ATRN-119 in the ABOYA-119 Phase 1/2a dose-escalation study, inand patientshave withclosed advancedthis solidstudy tumors.to focus our resources on the clinical development of APR-1051. Building on the completion of dose escalation, we are considering further ATRN-119 development in combination approaches that could expand its therapeutic potential. We believe ATRN-119's mechanism of action, favorable safety profile, and pharmacologic characteristics potentially make it an ideal candidate for combination with other anti-cancer therapies, including radiation therapy, chemotherapy, antibody-drug conjugates (ADCs) and immune checkpoint inhibitors. As part of this strategic focus, we have initiated an orderly wind-down of ABOYA-119 as we explore ATRN-119 in potential combination approaches.

In addition, we have an early-stage program, APR-1602, a macrocyclic DYRK1A/B inhibitor, that willwe bepotentially ready tocould enter IND-enablingIND enabling studies in the fourth quarter of 2026.2026, subject to available resources.

Research and development activities are central to our business model. Product candidates in later stages of clinical development generally have higher development costs than those in earlier stages of clinical development, primarily due to the increased size and duration of later-stage clinical trials. We expect that our research and development expenses will continue to increase for the foreseeable future as we progress clinical trials for APR-1051. With the current pause on further patient enrollment in both once daily and twice daily monotherapy dosing armsclosure of ABOYA-119 and the orderly wind-down of certain clinical trial site activities associated with the monotherapy arms asABOYA-119, we exploreare exploring ATRN-119 in potential combination approaches.approaches with potential partners.

We are a “smaller reporting company,” as such term is defined in Rule 12b-2 of the Exchange Act, meaning that the market value of our common stock held by non-affiliates is less than $700 million and our annual revenue is less than $100 million during the most recently completed fiscal year.Act. We maywill continue to be a smaller reporting company ifso long as either (i) the market value of our common stock held by non-affiliates is less than $250 million or (ii) our annual revenue is less than $100 million during the most recently completed fiscal year and the market value of our common stock held by non-affiliates is less than $700 million. As a smaller reporting company, we may continue to rely on exemptions from certain disclosure requirements that are available to smaller reporting companies.companies, Specifically,including as a smaller reporting company we may choose to presentpresenting only the two most recent fiscal years of audited financial statements in our Annual Report on Form 10-K and smaller reporting companies have reduced disclosure obligations regarding executive compensation.

Comparison of the three months ended MarchJune 31,30, 2026 and 2025

Grant revenue primarily from the National Cancer Institute of the National Institutes of Health (“NIH”) for the three months ended MarchJune 31,30, 2025 was $0.2$0.1 million. No grant revenue was recognized for the three months ended MarchJune 31,30, 2026.2026, Theas decreasethe in grant revenue of $0.2 million is due to recognizing less grant revenuegrants from the NIH as these grants have been exhausted.

Research and development expenses for the three months ended MarchJune 31,30, 2026 were approximately $1.6$2.5 million, compared to approximately $2.5$1.9 million for the three months ended MarchJune 31,30, 2025. The overall decreaseincrease of $0.9$0.6 million was primarily due to the following:

General and administrative expenses for the three months ended MarchJune 31,30, 2026 were approximately $1.8$1.6 million, compared to approximately $1.8$1.6 million for the three months ended MarchJune 31,30, 2025.

Foreign currency gain for the three months ended MarchJune 31,30, 2026 was $7,711$2,953 compared to a foreign currency loss of $51,803$29,124 for the three months ended MarchJune 31,30, 2025. The change in the foreign currency gain (loss) of $59,514$32,077 was primarily due to a strengthening of the U.S. dollar against the Swedish Krona during the three months ended MarchJune 31,30, 2026 as compared to the three months ended MarchJune 31,30, 2025. InterestOther income,income netwas $79,000 for the three months ended MarchJune 31,30, 2026 and was related to the monetization of a portion of the Company’s state net operating loss carryforwards. Interest income for the three months ended June 30, 2026 and 2025 primarily consisted of interest income on our cash and cash equivalents.

Since our inception, we have incurred significant losses on an aggregate basis. We have not yet commercialized any of our product candidates, which are in various phases of preclinical and clinical development, and we do not expect to generate revenue from sales of any products for several years, if at all. Our ability to generate product revenue sufficient to achieve profitability will depend on the successful development and eventual commercialization of one or more of our product candidates. Since 2019, our primary source of funds has been from the public sales of our common stock. As of MarchJune 31,30, 2026, we had cash and cash equivalents of $46.5$41.2 million. Based on our current operating plan, we believe that our existing cash and cash equivalents will enable us to fund our operating expenses and capital expenditure requirements into the first quarter of 2028.

Our net losses were $3.3$6.9 million and $3.9$7.2 million for the threesix months ended MarchJune 31,30, 2026 and 2025, respectively. As of MarchJune 31,30, 2026, we had an accumulated deficit of $336.9$340.5 million. These losses have resulted primarily from costs incurred in connection with research and development activities, patent investment, and general and administrative costs associated with our operations. We expect to continue to incur significant expenses and increasing operating losses for at least the next several years.

On November 8, 2024, we entered into an At the Market Offering Agreement, or the 2024 ATM Agreement, with H.C. Wainright & Co., LLC, or HCW. Pursuant to the 2024 ATM Agreement and the prospectus supplement filed in connection therewith, we may, from time to time, in our sole discretion, issue and sell through HCW, acting as sales agent and/or principal, up to $3.0 million of shares of our common stock. During the threesix months ended MarchJune 31,30, 2026, we did not issue and sell any shares of common stock under the 2024 ATM Agreement. During the year ended December 31, 2025, we issued and sold 1,337,948 shares of common stock under the 2024 ATM Agreement resulting in net proceeds of approximately $1.9 million.

Cash used in operating activities resulted primarily from our net losses adjusted for non-cash charges and changes in components of working capital. Net cash used in operating activities was $2.8$6.0 million for the threesix months ended MarchJune 31,30, 2026 compared to $3.6$6.8 million for the threesix months ended MarchJune 31,30, 2025. The decrease in cash used in operating activities of $0.8 million was primarily attributable to a change in operating assets and liabilities of $0.3$0.6 million and a decrease in our net loss of $0.6$0.3 million, partially offset by non-cash items of $0.1 million.

Cash used in investing activities for the six months ended June 30, 2026 of $15,400 was for the purchase of property and equipment. No cash was used in or provided by investing activities for the threesix months ended MarchJune 31, 2026 and30, 2025.

Net cash provided by financing activities was $34.6$32.7 million for the threesix months ended MarchJune 31,30, 2026. Cash provided by financing activities for the threesix months ended MarchJune 31,30, 2026 was attributable to the net proceeds of approximately $34.6$32.7 million, after deducting approximately $0.5$2.9 million in issuance costs, received from sales of common stock and pre-funded warrants in the January 2026 and March 2026 Private Placements. The Company incurred an additional $2.3 million of issuance costs that were paid in April 2026.

Net cash provided by financing activities of $0.1$0.4 million for the threesix months ended MarchJune 31,30, 2025 was attributable to the net proceeds of $0.1$0.4 million, after deducting approximately $3,000$18,000 in issuance costs, received from sales of common stock under the 2024 ATM Agreement.

As a result, we will need additional financing to support our continuing operations. Until such time as we can generate significant revenue from product sales, if ever, we expect to finance our operations through a combination of public or private equity or debt financings or other sources, which may include collaborations with third parties and grants from government and other (non-government) organizations. We may be unable to raise additional funds or enter into other agreements or arrangements when needed on favorable terms, or at all. If we fail to raise capital or enter into such agreements as and when needed, we may have to significantly delay, scale back or discontinue the development or commercialization of one or more of our product candidates. In addition, our ability to engage in certain types of capital raising transactions maywill be limited by the Listing Rules of the Nasdaq Stock Market and/or General Instruction I.B.6 of Form S-3 if the market value of our common stock held by non-affiliates is ever below $75 million at a time we seek to utilize our effective registration statement on Form S-3.