Xilio Therapeutics (XLO) Risk Analysis

On April 4, 2025, we received a deficiency letter from the Listing Qualifications Department, or the Nasdaq Staff, of the Nasdaq Stock Market LLC, or Nasdaq, notifying us that, for the last 30 consecutive business days, the bid price for our common stock had closed below $1.00 per share, which is the minimum bid price required to maintain continued listing on the Nasdaq Global Select Market, referred to as the minimum bid price requirement. In accordance with Nasdaq Listing Rules, we had an initial period of 180 calendar days, or until October 1, 2025, to regain compliance with the minimum bid price requirement. On August 22, 2025, we received a second deficiency notice from the Nasdaq Staff notifying us that we were not in compliance with the minimum $10.0 million stockholders' equity requirement for continued listing on the Nasdaq Global Select Market. This second deficiency notice was only a notification of deficiency, not of imminent delisting, and had no immediate effect on the listing or trading of our securities on the Nasdaq Global Select Market. On October 2, 2025, we received a letter from the Nasdaq Staff approving our application to list our securities on the Nasdaq Capital Market. Our securities were transferred to the Nasdaq Capital Market at the opening of business on October 6, 2025. In connection with the transfer to the Nasdaq Capital Market, Nasdaq granted us an additional 180 calendar day period, or until March 30, 2026, to regain compliance with the minimum bid price requirement. If, at any time before March 30, 2026, the closing bid price for our common stock is at least $1.00 per share for a minimum of 10 consecutive business days, the Nasdaq Staff will provide written notification to us that we are in compliance with the minimum bid price requirement, unless the Nasdaq Staff exercises its discretion to extend this 10-day period pursuant to the Nasdaq Listing Rules. On February 23, 2026, our stockholders voted to adopt and approve an amendment to our restated certificate of incorporation, as amended, to effect a reverse stock split of our issued shares of common stock and our board of directors elected to implement a reverse stock split at a ratio of 1-for-14, which reverse stock split became effective on March 13, 2026 at 5:00 p.m. Eastern Time. However, if we do not regain compliance with the minimum bid price requirement by March 30, 2026, or if we do not meet the other listing standards, the Nasdaq Staff will provide us with notice that our common stock may be delisted. At that time, we may appeal the Nasdaq Staff's delisting determination to a Nasdaq Listing Qualifications Panel. However, there can be no assurance that, even if we appeal the Nasdaq Staff's delisting determination to the panel, such appeal would be successful. If we are unable to comply with applicable Nasdaq listing standards, shares of our common stock would be subject to delisting, which could have a material adverse effect on the market for, and liquidity and price of, our common stock and would adversely affect our ability to raise capital on terms acceptable to us, or at all. Delisting from Nasdaq could also have other negative results, including, without limitation, the potential loss of confidence by investors, customers and employees and fewer business development opportunities. Any delisting of our common stock from Nasdaq would also make it more difficult for our stockholders to sell their shares of our common stock in the public market.

As discussed above, we recently implemented a reverse stock split of our common stock. The reverse stock split may not achieve the intended benefit of increasing the per share market price of our common stock, and there are a number of risks associated with the reverse stock split, including, without limitation: - the reverse stock split may not result in a price per share that will successfully attract certain types of investors, and such resulting share price may not satisfy the investing guidelines of institutional investors or investment funds;- the trading liquidity of the shares of our common stock may not improve, or may decline, as a result of the reverse stock split and there can be no assurance that the reverse stock split will result in the intended benefits; and - the reverse stock split could be viewed negatively by the market and other factors, which may adversely affect the market price of our common stock. There can also be no assurances the reverse stock split will prevent the delisting of our common stock from the Nasdaq Capital Market, which could have a material adverse effect on our business.

The trading volume and market price of our common stock has been, and may continue to be, subject to significant fluctuations in response to numerous factors, many of which are beyond our control. The stock market in general and the market for biotechnology and pharmaceutical companies in particular have experienced extreme volatility that has often been unrelated to the operating performance of particular companies. As a result of this volatility, investors may not be able to sell their common stock at or above the price paid for the shares. The trading volume and market price for our common stock may be influenced by many factors, including: - our recently effected reverse stock split of our common stock, which became effective March 13, 2026;- the results from our preclinical studies and clinical trials;- the commencement, enrollment or results of any current or future clinical trials we may conduct, or changes in the development status of our product candidates;- adverse results from, delays in initiating or completing, or termination of clinical trials;- unanticipated serious safety concerns related to the use of our product candidates;- clinical trial results from, or regulatory developments regarding, a competitor's product candidate;- adverse regulatory decisions, including failure to receive regulatory approval of our product candidates;- regulatory or legal developments in the U.S. and foreign countries;- any delay in our regulatory filings for our product candidates and any adverse development or perceived adverse development with respect to the applicable regulatory authority's review of such filings, including without limitation the FDA's issuance of a "refusal to file" letter or a request for additional information;- the public's response to press releases or other public announcements by us or third parties, including our filings with the SEC, and announcements relating to acquisitions, strategic transactions, licenses, joint ventures, collaborations, capital commitments, intellectual property, litigation or other disputes impacting us or our business;- lower than expected market acceptance of our product candidates, if approved;- adverse developments concerning our manufacturers;- our inability to obtain adequate product supply for any product candidate, or approved product or inability to do so at acceptable prices;- variations in the level of expenses related to our preclinical and clinical development programs, including relating to the timing of invoices from, and other billing practices of, our CROs and clinical trial sites;- variations in the level of expenses related to our commercialization activities, if any product candidates are approved;- the clinical results of our competitors or potential competitors;- introduction of new products or services by our competitors;- changes in financial estimates by us or by any securities analysts who might cover our common stock;- conditions or trends in our industry;- our cash position;- sales of our common stock by us or our stockholders in the future, including the common stock that may be issuable upon the exercise of outstanding prefunded warrants and common stock warrants, or the perception that such sales could occur;- adoption of new, or changes to current accounting standards;- ineffectiveness of our internal controls;- changes in the market valuations of similar companies;- stock market price and volume fluctuations of comparable companies and, in particular, those that operate in the biotechnology and pharmaceutical industry;- publication of research reports about us or our industry or positive or negative recommendations or withdrawal of research coverage by securities analysts;- announcements by us or our competitors of significant acquisitions, strategic partnerships or divestitures;- announcements of investigations or regulatory scrutiny of our operations or lawsuits filed against us;- changes in the structure of healthcare payment systems;- investors' general perception of our company and our business;- overall performance of the equity markets;- potential inclusion or exclusion of our common stock in exchange, industry, or other tracking indices;- disputes or other developments relating to proprietary rights, including patents, litigation matters and our ability to obtain patent protection for our technologies and product candidates;- significant lawsuits, including patent or stockholder litigation;- proposed changes to healthcare laws, intellectual property laws or pharmaceutical pricing in the U.S. or foreign jurisdictions, or speculation regarding such changes;- future sales of our common stock by our officers, directors and significant stockholders;- recruitment or departure of key personnel;- public health epidemics or pandemics, such as the COVID-19 pandemic, and any recession, depression, or other sustained adverse market event or economic impact resulting from such epidemics or pandemics;- general political, economic, industry and market conditions; and - other events or factors described in this "Risk Factors" section, many of which are beyond our control. In addition, in the past, stockholders have initiated class action lawsuits against pharmaceutical and biotechnology companies following periods of volatility in the market prices of these companies' stock. This risk is especially relevant for us, because biopharmaceutical companies have experienced significant stock price volatility in recent years. Such litigation, if instituted against us, could cause us to incur substantial costs and divert management's attention and resources from our business.

The trading market for our common stock relies, in part, on the research and reports that securities or industry analysts publish about us or our business. Currently, one securities and industry analyst publishes research on our company. There can be no assurance that the existing analyst will continue to cover us or that new analysts will begin to cover us. There is also no assurance that the covering analyst will provide favorable coverage. Although we have obtained analyst coverage, if the analyst covering our business downgrades her evaluation of our stock or publishes inaccurate or unfavorable research about our business, or provides more favorable relative recommendations about our competitors, the price of our stock could decline. In the past, analysts have ceased to cover our stock and others may cease to do so in the future. As a result, we could lose visibility in the market for our stock, which in turn could cause our stock price and trading volume to decline.

As of December 31, 2025, our executive officers, directors, holders of 5% or more of our common stock and their respective affiliates beneficially owned shares in the aggregate representing a majority of our outstanding common stock. As a result of their share ownership, these stockholders, if they act together, would have the ability to influence our management and policies and would be able to significantly affect the outcome of matters requiring stockholder approval, such as elections of directors, amendments of our organizational documents or approvals of any merger, sale of assets or other major corporate transaction. This may prevent or discourage unsolicited acquisition proposals or offers for our common stock that our stockholders may feel are in their best interest. Some of these persons or entities may have interests different than our unaffiliated stockholders, or they may want us to pursue strategies that deviate from the interests of other stockholders. In addition, this concentration of ownership might adversely affect the market price of our common stock by: - delaying, deferring or preventing a change of control of us;- entrench our management and board of directors;- impeding a merger, consolidation, takeover or other business combination involving us; or - discouraging a potential acquirer from making a tender offer or otherwise attempting to obtain control of us.

We are an "emerging growth company," or EGC, as defined in the Jumpstart Our Business Startups Act of 2012, or the JOBS Act. We expect to remain an EGC until December 31, 2026. For so long as we remain an EGC, we are permitted and intend to rely on exemptions from certain disclosure requirements that are applicable to other public companies that are not EGCs. These exemptions include: - being permitted to provide only two years of audited financial statements, in addition to any required unaudited interim financial statements, with correspondingly reduced "Management's Discussion and Analysis of financial Condition and Results of Operations" disclosure;- not being required to comply with the auditor attestation requirements in the assessment of our internal control over financial reporting;- not being required to comply with any requirement that may be adopted by the Public Company Accounting Oversight Board regarding mandatory audit firm rotation or a supplement to the auditor's report providing additional information about the audit and the financial statements;- reduced disclosure obligations regarding executive compensation; and - exemptions from the requirements of holding a nonbinding advisory vote on executive compensation and stockholder approval of any golden parachute payments not previously approved. Even after we no longer qualify as an emerging growth company, we may continue to qualify as a smaller reporting company, which would allow us to take advantage of many of the same exemptions from disclosure requirements, including reduced disclosure obligations regarding executive compensation. In addition, if we are a smaller reporting company with less than $100 million in annual revenue, we would not be required to comply with the auditor attestation requirements of Section 404 of the Sarbanes-Oxley Act of 2002, or Section 404. We cannot predict whether investors will find our common stock less attractive if we rely on these exemptions. If some investors find our common stock less attractive as a result, there may be a less active trading market for our common stock and our stock price may be more volatile. In addition, the JOBS Act permits an EGC to take advantage of an extended transition period to comply with new or revised accounting standards applicable to public companies until those standards would otherwise apply to private companies. We have elected not to "opt out" of such extended transition period, which means that when a standard is issued or revised and it has different application dates for public or private companies, we can adopt the new or revised standard at the time private companies adopt the new or revised standard and may do so until such time that we either (1) irrevocably elect to "opt out" of such extended transition period or (2) no longer qualify as an EGC or a smaller reporting company. We may choose to early adopt any new or revised accounting standards whenever such early adoption is permitted for private companies.

Provisions in our restated certificate of incorporation and our second amended and restated bylaws may discourage, delay or prevent a merger, acquisition or other change in control of our company that stockholders may consider favorable, including transactions in which our stockholders might otherwise receive a premium for their shares. These provisions could also limit the price that investors might be willing to pay in the future for shares of our common stock, thereby depressing the market price of our common stock. In addition, because our board of directors is responsible for appointing the members of our management team, these provisions may frustrate or prevent any attempts by our stockholders to replace or remove our current management by making it more difficult for stockholders to replace members of our board of directors. Among other things, these provisions: - establish a classified board of directors such that only one of three classes of directors is elected each year;- allow the authorized number of our directors to be changed only by resolution of our board of directors;- limit the manner in which stockholders can remove directors from our board of directors;- establish advance notice requirements for stockholder proposals that can be acted on at stockholder meetings and nominations to our board of directors;- require that stockholder actions must be effected at a duly called stockholder meeting and prohibit actions by our stockholders by written consent;- limit who may call stockholder meetings;- authorize our board of directors to issue preferred stock without stockholder approval, which could be used to institute a "poison pill" that would work to dilute the stock ownership of a potential hostile acquirer, effectively preventing acquisitions that have not been approved by our board of directors; and - require the approval of the holders of at least two-thirds of the votes that all our stockholders would be entitled to cast to amend or repeal specified provisions of our certificate of incorporation or bylaws. In addition, these provisions would apply even if we were to receive an offer that some stockholders may consider beneficial. Moreover, because we are incorporated in Delaware, we are governed by the provisions of Section 203 of the Delaware General Corporation Law, or the DGCL, which prohibits a person who owns in excess of 15% of our outstanding voting stock from merging or combining with us for a period of three years after the date of the transaction in which the person acquired in excess of 15% of our outstanding voting stock, unless the merger or combination is approved in a prescribed manner. Our restated certificate of incorporation designates the Court of Chancery of the State of Delaware and the federal district courts of the United States of America as the sole and exclusive forum for certain types of actions and proceedings that may be initiated by our stockholders, which could limit our stockholders' ability to obtain a favorable judicial forum for disputes with us or our directors, officers and employees and increase the costs to our stockholders of bringing such claims. Our restated certificate of incorporation provides that, unless we consent in writing to the selection of an alternative forum, the Court of Chancery of the State of Delaware (or, if the Court of Chancery of the State of Delaware does not have jurisdiction, the federal district court for the District of Delaware) will be the sole and exclusive forum for the following types of actions or proceedings under Delaware statutory or common law: - any derivative action or proceeding brought on our behalf;- any action asserting a claim of breach of a fiduciary duty owed by any of our directors, officers, employees or stockholders to our company or our stockholders;- any action asserting a claim arising pursuant to any provision of the DGCL or as to which the DGCL confers jurisdiction on the Court of Chancery of the State of Delaware; or - any action asserting a claim arising pursuant to any provision of our certificate of incorporation or bylaws (in each case, as they may be amended from time to time) or governed by the internal affairs doctrine. The choice of forum provisions will not apply to suits brought to enforce a duty or liability created by the Exchange Act. Furthermore, Section 22 of the Securities Act creates concurrent jurisdiction for federal and state courts over all such Securities Act actions, and investors cannot waive compliance with the federal securities laws and the rules and regulations thereunder. Accordingly, both state and federal courts have jurisdiction to entertain such claims. To prevent having to litigate claims in multiple jurisdictions and the threat of inconsistent or contrary rulings by different courts, among other considerations, our restated certificate of incorporation provides that, unless we consent in writing to the selection of an alternative forum, the federal district courts of the United States of America shall, to the fullest extent permitted by law, be the sole and exclusive forum for the resolution of any claims arising under the Securities Act. While the Delaware courts have determined that such choice of forum provisions are facially valid, a stockholder may nevertheless seek to bring a claim in a venue other than those designated in the exclusive forum provisions. In such instance, we would expect to vigorously assert the validity and enforceability of the exclusive forum provisions of our restated certificate of incorporation. This may require significant additional costs associated with resolving such action in other jurisdictions and there can be no assurance that the provisions will be enforced by a court in those other jurisdictions. These exclusive forum provisions may limit the ability of our stockholders to bring a claim in a judicial forum that such stockholders find favorable for disputes with us or our directors, officers or employees, and increase the costs to such stockholders of bringing such a claim, either of which may discourage such lawsuits against us and our directors, officers and employees. If a court were to find that either exclusive forum provision contained in our restated certificate of incorporation to be inapplicable or unenforceable in an action, we may incur further significant additional costs associated with resolving such action in other jurisdictions, all of which could materially adversely affect our business, financial condition and operating results.

We currently anticipate that we will retain future earnings for the development, operation and expansion of our business and do not anticipate declaring or paying any cash dividends for the foreseeable future. Any determination to pay dividends in the future will be at the sole discretion of our board of directors. In addition, the terms of any future debt agreements may preclude us from paying dividends. Any return to stockholders will therefore be limited in the foreseeable future to the appreciation of their stock.

Effective internal control over financial reporting is necessary for us to provide reliable financial reports and, together with adequate disclosure controls and procedures, is designed to prevent fraud. Any failure to implement required new or improved controls, or difficulties encountered in their implementation could cause us to fail to meet our reporting obligations. In addition, any testing by us conducted in connection with Section 404, or any subsequent testing by our independent registered public accounting firm, may reveal deficiencies in our internal control over financial reporting that are deemed to be material weaknesses or that may require prospective or retroactive changes to our financial statements or identify other areas for further attention or improvement. Inferior internal controls could also subject us to regulatory scrutiny and sanctions, impair our ability to raise revenue and cause investors to lose confidence in our reported financial information, which could harm our business and have a negative effect on the trading price of our common stock and adversely affect our results of operations and financial condition. We are required to disclose changes made in our internal controls and procedures on a quarterly basis and our management is required to assess the effectiveness of these controls annually. However, for as long as we are an EGC or a smaller reporting company with less than $100 million in annual revenue, our independent registered public accounting firm will not be required to attest to the effectiveness of our internal control over financial reporting pursuant to Section 404. An independent assessment of the effectiveness of our internal control over financial reporting could detect problems that our management's assessment might not. Undetected material weaknesses in our internal control over financial reporting could lead to financial statement restatements and require us to incur the expense of remediation, which could have a negative effect on the trading price of our common stock and adversely affect our results of operations and financial condition.

As a public company, we are subject to certain reporting requirements of the Securities Exchange Act of 1934, as amended, or the Exchange Act. Our disclosure controls and procedures are designed to reasonably assure that information required to be disclosed by us in reports we file or submit under the Exchange Act is accumulated and communicated to management, recorded, processed, summarized and reported within the time periods specified in the rules and forms of the SEC. We believe that any disclosure controls and procedures or internal control over financial reporting, no matter how well conceived and operated, can provide only reasonable, not absolute, assurance that the objectives of the control system are met. These inherent limitations include the realities that judgments in decision-making can be faulty, and that breakdowns can occur because of simple error or mistake. Additionally, controls can be circumvented by the individual acts of some persons, by collusion of two or more people or by an unauthorized override of the controls. Accordingly, because of the inherent limitations in our control system, misstatements or insufficient disclosures due to error or fraud may occur and not be detected.

Since inception, we have incurred significant operating losses, including net losses of $35.0 and $58.2 million for the years ended December 31, 2025 and 2024, respectively. As of December 31, 2025, we had an accumulated deficit of $418.8 million. We expect our operating losses and negative operating cash flows to continue for the foreseeable future as we continue to advance our pipeline of novel, masked immuno-oncology, or I-O, molecules through preclinical and clinical development, maintain the infrastructure necessary to support these activities and continue to incur costs associated with operating as a public company. We do not expect to generate any revenue from the sale of products for a number of years, if at all, and any such revenue will not be realized unless and until we obtain marketing approval for and successfully launch and commercialize a product candidate. If we obtain marketing approval for any current or future product candidates that we develop, we expect to incur significant commercialization expenses related to product sales, marketing, distribution and manufacturing. Some of these expenses may be incurred in advance of marketing approval and could be substantial. To date, we have financed our operations primarily from proceeds raised through private placements of equity securities; sales of common stock in our initial public offering, or IPO, and through "at-the-market" offerings; the sale of prefunded warrants in our June 2025 and February 2026 follow-on offerings; the exercise of certain common stock warrants issued in connection with our June 2025 follow-on offering; development event payments under our co-funded clinical trial collaboration with F. Hoffmann-La Roche Ltd, or Roche; and upfront and milestone payments under our collaboration and license agreements with AbbVie and Gilead. All of our programs are in clinical or preclinical development. As a result, we have not generated any revenue from product sales and do not expect to generate any revenue from product sales for at least the next several years, if at all. We expect our operating losses and negative operating cash flows to continue for the foreseeable future as we continue to advance our pipeline of novel, masked I-O molecules through development. Our operating expenses and net losses may fluctuate significantly from quarter to quarter and year to year, and we expect to continue to incur significant expenses and operating losses for the foreseeable future, particularly to the extent we: - continue to advance our current research programs and conduct additional research programs;- advance our current product candidates and any future product candidates we may develop into preclinical and clinical development;- seek marketing approvals for product candidates that successfully complete clinical trials, if any;- obtain, expand, maintain, defend and enforce our intellectual property;- continue to discover, validate and develop additional product candidates;- continue to manufacture increasing quantities of our current or future product candidates for use in preclinical studies, clinical trials and for any potential commercialization;- acquire or in-license other product candidates, technologies or intellectual property;- hire additional personnel to support current or future programs;- establish a commercial and distribution infrastructure to commercialize products for which we may obtain marketing approval, if any; and - incur additional costs associated with current and future research, development and commercialization efforts and operations as a public company. Even if we successfully complete clinical trials and obtain regulatory approval for one or more of our product candidates, our ability to generate product revenue sufficient to achieve profitability will depend heavily on the successful commercialization of those product candidates. Because of the numerous risks and uncertainties associated with product development, we are unable to predict the timing or amount of increased expenses or when or if we will be able to achieve profitability. In addition, even if we are able to generate revenue from product sales, we may not become profitable.

To date, we have not generated any revenue from product sales. We do not expect to generate any revenue from the sale of products for a number of years, and we may never generate revenue from the sale of products. Our ability to generate revenue from product sales depends on a number of factors, including our ability to: - successfully complete our ongoing and planned preclinical studies and clinical trials for any current or future product candidates;- successfully receive U.S. Food and Drug Administration, or FDA, clearance for any investigational new drug application, or IND, for any current or future product candidates;- successfully initiate and complete clinical trials for our clinical-stage product candidates and any other current or future product candidates, including all safety and efficacy studies necessary to obtain U.S. and foreign regulatory approval for our product candidates;- establish and maintain clinical and commercial manufacturing capabilities or make arrangements with third-party manufacturers for clinical supply and commercial manufacturing;- launch commercial sales of our products, if and when approved, whether alone or in collaboration with others;- obtain and maintain acceptance of the products, if and when approved, by patients, the medical community and third-party payors;- effectively compete with other therapies;- obtain and maintain healthcare coverage and adequate reimbursement for our products, if and when approved;- maintain a continued acceptable safety profile of our products following approval; and - enforce and defend intellectual property rights and claims. Because of the numerous risks and uncertainties associated with biopharmaceutical product development, we are unable to accurately predict the timing or amount of expenses we may incur in connection with these activities prior to generating revenue from product sales. In addition, we may never succeed in these activities, and, even if we do, we may never generate revenues that are significant enough to achieve profitability. Even if we do achieve profitability, we may not be able to sustain or increase profitability on a quarterly or annual basis. Our failure to become and remain profitable would depress the value of our company and could impair our ability to raise capital, expand our business, maintain our research and development efforts, diversify our product candidates or even continue our operations. A decline in the value of our company could also cause our stockholders to lose all or part of their investment.

We are a clinical-stage biotechnology company with a limited operating history upon which investors can evaluate our business and prospects. Since inception, we have devoted substantially all of our financial resources and efforts to performing research and development activities. Our approach to the discovery and development of masked I-O product candidates using our proprietary platform technology is unproven, and we do not know whether we will be able to develop any approved products of commercial value. In addition, each of our product candidates is either in early clinical or preclinical development, and all of our other development programs are still in discovery stages. We have not yet demonstrated an ability to successfully complete any late-stage clinical trials, obtain regulatory approvals, manufacture a commercial-scale product, or arrange for a third party to do so on our behalf, or conduct the sales and marketing activities necessary for successful product commercialization. Consequently, any predictions made about our future success or viability may not be as accurate as they could be if we had a history of successfully developing and commercializing biopharmaceutical products.

We have incurred substantial losses during our history. As of December 31, 2025, we had federal and state net operating loss, or NOL, carryforwards of $263.5 million and $234.6 million, respectively. We do not anticipate generating revenue from sales of products for the foreseeable future, if ever, and we do not know whether or when we will generate taxable income necessary to utilize our NOLs. In general, under Sections 382 and 383 of the Internal Revenue Code of 1986, as amended, or the Code, and corresponding provisions of state law, if a corporation undergoes an "ownership change" (generally defined as a greater than 50 percentage point change (by value) in the ownership of its equity by certain stockholders over a three-year period), the corporation's ability to use its pre-change NOL carryforwards and other pre-change tax attributes to offset its post-change income is subject to limitations. In the second quarter of 2024, we had an ownership change as defined by Sections 382 and 383 of the Code. As a result, if we earn net taxable income, our ability to use our pre-change NOL carryforwards and other pre-change tax attributes to offset such taxable income may be subject to limitations, which could result in increased future tax liability to us and could have an adverse effect on our future results of operations. There is also a risk that due to regulatory changes, such as suspensions on the use of NOLs, or other unforeseen reasons, our existing NOLs could expire or otherwise become unavailable to offset future income tax liabilities. As described below in "Risks Related to Ownership of Our Common Stock-Changes in tax laws or in their implementation or interpretation may adversely affect our business and financial condition," the Tax Cuts and Jobs Act of 2017, or the Tax Act, as amended by the Coronavirus Aid, Relief, and Economic Security Act, or the CARES Act, includes changes to U.S. federal tax rates and the rules governing NOL carryforwards that may significantly impact our ability to utilize our NOLs to offset taxable income in the future. In addition, state NOLs generated in one state cannot be used to offset income generated in another state. For these reasons, even if we attain profitability, we may be unable to use a material portion of our NOLs and other tax attributes.

As of December 31, 2025, we had cash and cash equivalents of $137.5 million. In the first quarter of 2026, we received net proceeds of approximately $37.3 million, after deducting underwriting discounts and commissions and estimated offering expenses payable by us, upon the closing of a follow-on offering of prefunded warrants and a $5.0 million development milestone related to the collaboration agreement with AbbVie Group Holdings Limited, or AbbVie. Based on our current operating plans, we anticipate that our existing cash and cash equivalents will be sufficient to enable us to fund our operating expenses and capital expenditure requirements through the end of 2027. This estimate excludes any potential future milestone payments, option-related fees or other contingent payments under our existing collaboration and partnership agreements with AbbVie and Gilead Sciences, Inc., or Gilead, and excludes the potential receipt of up to $36.2 million in additional gross proceeds in the second half of 2026 if all outstanding Series C warrants are exercised at their current exercise price. In addition, we have based our estimates on assumptions that may prove to be wrong, and we could exhaust our available capital resources sooner than we anticipate and may need to seek additional capital sooner than anticipated. Our future capital requirements, both short-term and long-term, will depend on many factors, including, but not limited to: - the scope, progress, results and costs of research and development for our current and future product candidates, including our current and planned clinical trials for our clinical-stage product candidates, vilastobart and efarindodekin alfa, and ongoing preclinical development for our current and future product candidates;- our ability to maintain our collaboration and license agreements with AbbVie and Gilead;- the timing and amount of milestones, option-related fees and other contingent payments under our collaboration, license and option agreement with AbbVie for masked immunotherapies and our license agreement with Gilead for efarindodekin alfa, as well as the scope, costs and timing of our development obligations under these agreements;- the potential receipt of up to $36.2 million in additional gross proceeds in the second half of 2026 if all of the outstanding Series C common stock warrants issued in connection with our June 2025 follow-on offering are exercised at their current exercise price of $10.50 per warrant;- our ability to secure additional capital in the future;- the scope, prioritization and number of our research and development programs;- the costs of securing manufacturing materials for use in preclinical studies, clinical trials and, for any product candidates for which we receive regulatory approval, if any, commercial supply;- the costs and timing of preparing, filing and prosecuting patent applications, maintaining and enforcing our intellectual property and proprietary rights and defending any intellectual property-related claims;- the extent to which we may acquire or in-license other products, product candidates, technologies or intellectual property, as well as the terms of any such arrangements;- the scope, costs, timing and outcome of regulatory review of our product candidates;- the costs and timing of future commercialization activities for any of our product candidates for which we receive regulatory approval;- the amount and timing of revenue, if any, received from commercial sales of any product candidates for which we receive regulatory approval;- general economic conditions, including inflation and the imposition of new or revised global trade tariffs; and - the costs of maintaining our operations and continuing to operate as a public company. Our existing cash and cash equivalents will not be sufficient to complete development of any current or future product candidates, and we will require additional capital in the future to sustain our operations. We currently do not have any committed external sources of funds and will be required to obtain further funding in the future through public or private equity offerings, debt, collaborations, licensing arrangements, the conversion of common stock warrants for cash, or other sources. However, adequate additional capital may not be available to us in the future on acceptable terms, or at all. In addition, our ability to raise additional capital may be adversely impacted by potential worsening economic conditions, both inside and outside the United States, including without limitation heightened inflation, capital market volatility, interest rate and currency rate fluctuations, any potential economic slowdown or recession, future pandemics, geopolitical tensions, including trade wars or civil or political unrest, or wars or other armed conflicts. Our failure to raise additional capital in the future as and when needed to support our operations would have a material adverse effect on our financial condition, our ability to develop and commercialize our current and any future product candidates or otherwise pursue our business strategy.

Our management has broad discretion in the application of our cash and cash equivalents and could use such funds in ways that do not improve our results of operations or enhance the value of our common stock. The failure by our management to apply these funds effectively could result in financial losses that could have a material adverse effect on our business, cause the price of our common stock to decline and delay the development of our product candidates. Pending their use, we may invest these funds in a manner that does not produce income or that loses value.

From time to time, we may consider strategic transactions, such as acquisitions of companies, asset purchases and out-licensing or in-licensing of intellectual property, products or technologies. Additional potential transactions that we may consider in the future include a variety of business arrangements, including spin-offs, strategic partnerships, joint ventures, restructurings, divestitures, business combinations and investments. Any future transactions could increase our near and long-term expenditures, result in potentially dilutive issuances of our equity securities, including our common stock, or the incurrence of debt, contingent liabilities, amortization expenses or acquired in-process research and development expenses, any of which could affect our financial condition, liquidity and results of operations. Future acquisitions may also require us to obtain sufficient additional capital, which may not be available on favorable terms or at all. These transactions may not be successful and may require significant time and attention of management. In addition, the integration of any business that we may acquire in the future may disrupt our existing business and may be a complex, risky and costly endeavor for which we may never realize any or all potential benefits of the acquisition. Accordingly, although there can be no assurance that we will undertake or successfully complete any additional transactions of the nature described above, any additional transactions that we do complete could have a material adverse effect on our business, results of operations, financial condition and prospects.

As a public company, we have incurred and will continue to incur substantial legal, accounting and other expenses. The Sarbanes-Oxley Act of 2002, or the Sarbanes-Oxley Act, the Dodd-Frank Wall Street Reform and Consumer Protection Act, Nasdaq listing requirements, and other applicable securities rules and regulations impose various requirements on public companies, including establishment and maintenance of effective disclosure and financial controls and corporate governance practices. Our management and other personnel will need to devote a substantial amount of time to these compliance initiatives. Moreover, these rules and regulations will continue to increase our legal and financial compliance costs and will make some activities more time-consuming and costly. We evaluate developments in these rules and regulations as they are promulgated and cannot predict or estimate the amount of additional costs we may incur or the timing of such costs. These rules and regulations are often subject to varying interpretations, in many cases due to their lack of specificity, and, as a result, their application in practice may evolve over time as new guidance is provided by regulatory and governing bodies. This could result in continuing uncertainty regarding compliance matters and higher costs necessitated by ongoing revisions to disclosure and governance practices. We intend to continue to invest resources to comply with evolving laws, regulations and standards, and this investment may result in increased general and administrative expenses and a diversion of management's time and attention from revenue-generating activities to compliance activities. If notwithstanding our efforts to comply with new laws, regulations and standards, we fail to comply, regulatory authorities may initiate legal proceedings against us and our business may be materially adversely effected. Pursuant to Section 404, we are required to furnish a report by our management on our internal control over financial reporting. However, while we remain an EGC or a smaller reporting company with less than $100 million in annual revenue, we will not be required to include an attestation report on internal control over financial reporting issued by our independent registered public accounting firm. To comply with Section 404, we are engaged in a process to document and evaluate our internal control over financial reporting, which is both costly and challenging. In this regard, we will need to continue to dedicate internal resources, potentially engage outside consultants and adopt a detailed work plan to assess and document the adequacy of internal control over financial reporting, continue steps to improve control processes as appropriate, validate through testing that controls are functioning as documented and implement a continuous reporting and improvement process for internal control over financial reporting. Despite our efforts, there is a risk that we will not be able to conclude, within the prescribed timeframe or at all, that our internal control over financial reporting is effective as required by Section 404. If we identify one or more material weaknesses in our internal control over financial reporting, it could result in an adverse reaction in the financial markets due to a loss of confidence in the reliability of our financial statements.

In March 2024, our wholly-owned subsidiary, Xilio Development, Inc., or Xilio Development, entered into a license agreement with Gilead, pursuant to which Gilead was granted an exclusive global license to develop and commercialize efarindodekin alfa, our masked IL-12, and other specified molecules directed toward IL-12. In February 2025, Xilio Development entered into a collaboration, license and option agreement with AbbVie, pursuant to which AbbVie was granted (i) an exclusive option for (a) an initial program to discover, develop and commercialize masked T cell engager molecules for an agreed upon initial target and backup target and (b) subject to the terms of the agreement, up to two additional programs to discover, develop, and commercialize masked T cell engager molecules for an initial target and backup target determined at the time of program initiation and (ii) an exclusive license to develop and commercialize a masked antibody-based immunotherapy. We may in the future seek third-party collaborators or licensors for the research, development and commercialization of other current or future product candidates. With respect to our agreements with Gilead and AbbVie, and what we expect will be the case with any future collaboration agreements we enter into, we have and would likely have limited control over whether such collaborators pursue the development of our product candidates or the amount and timing of resources that our collaborators dedicate to the development or commercialization of our product candidates that we seek to develop with them. For example, under the license agreement with Gilead, if Gilead exercises its right to transition responsibilities for the development and commercialization of efarindodekin alfa and the rest of our IL-12 program, it will have sole decision-making authority with respect to the continued development and future commercialization of our IL-12 program and may elect to prioritize other assets that it believes are more competitive, or it may exercise its right to terminate the license and return the licensed IL-12 program assets to us. Similarly, subject to limited exceptions, AbbVie has sole decision-making authority with respect to the development and commercialization of the masked antibody-based immunotherapy program. With respect to any T cell engager program for which AbbVie exercises its option, AbbVie will have sole decision-making authority with respect to the continued development and future commercialization of such option program and may elect to prioritize other assets that it believes are more competitive, or it may exercise its right to terminate the license and return the licensed T cell engager program assets to us. As a result, there can be no assurances that any of the programs covered by our existing or future collaborations or licenses will be developed further or reach commercialization. Further, our ability to generate revenues from these existing and future arrangements will depend on our collaborators' abilities to successfully perform the functions assigned to them in these arrangements. We cannot predict the success of any collaboration that we enter into. Collaborations, licenses or similar arrangements involving our research programs or any product candidates currently pose, and will continue to pose, numerous risks to us, including the following: - collaborators or licensors have significant discretion in determining the efforts and resources that they will apply to these arrangements;- collaborators or licensors may not pursue development and commercialization of our product candidates or may elect not to continue or renew development or commercialization programs based on clinical trial results, changes in such third party's strategic focus or available funding or external factors such as an acquisition that diverts resources or creates competing priorities;- collaborators or licensors may delay programs, preclinical studies or clinical trials, provide insufficient funding for programs, preclinical studies or clinical trials, stop a preclinical study or clinical trial or abandon a product candidate, repeat or conduct new clinical trials or require a new formulation of a product candidate for clinical testing;- collaborators or licensors could independently develop, or develop with third parties, products that compete directly or indirectly with our product candidates if the collaborators believe that competitive products are more likely to be successfully developed or can be commercialized under terms that are more economically attractive than ours;- collaborators or licenses may be acquired by a third party having competitive products or different priorities;- collaborators or licensors with marketing and distribution rights to one or more product candidates may not commit sufficient resources to the marketing and distribution of such product candidate(s);- collaborators or licensors may not properly obtain, maintain, enforce or defend our intellectual property or proprietary rights or may use our proprietary information in such a way as to invite litigation that could jeopardize or invalidate our proprietary information or expose us to potential litigation;- disputes may arise between the collaborators or licensors and us that result in the delay or termination of the research, development, or commercialization of our product candidates or any of our product candidates or that result in costly litigation or arbitration that diverts management attention and resources or that jeopardize or invalidate our intellectual property or proprietary information;- we may lose certain valuable rights under certain circumstances, including if we undergo a change of control;- collaborations or licenses may be terminated and, if terminated, may result in a need for additional capital to pursue further development or commercialization of the applicable product candidates; and - collaborations or license agreements may not lead to development or commercialization of product candidates in the most efficient manner or at all. If a present or future collaborator or licensor of ours were to be involved in a business combination, the continued pursuit and emphasis on our product development or commercialization program under such collaboration could be delayed, diminished or terminated. If our current or future collaborations, licenses or similar transactions do not result in the successful development and commercialization of product candidates, including if one of our current or future collaborators or licensors terminates its agreement with us, we may not receive any future payments for which we might otherwise be eligible under such agreement or we may incur significant costs in re-establishing the development and manufacturing of such product candidates. If we do not receive the funding we expect under these agreements, our development of product candidates could be delayed, and we may need additional resources to develop such product candidates. In addition, if one of our collaborators terminates its agreement with us, we may find it more difficult to find a suitable replacement collaborator or licensor or for us to attract new collaborators or licensors, and our development programs may be delayed or the perception of us in the business and financial communities could be adversely affected. All of the risks relating to product development, regulatory approval and commercialization described in this Annual Report on Form 10-K apply to the activities of our collaborators or licensors. These relationships, or those like them, may require us to incur non-recurring and other charges, increase our near- and long-term expenditures, issue securities that dilute our existing stockholders, or disrupt our management and business. In addition, we could face significant competition in seeking appropriate collaborators, and the negotiation process is time-consuming and complex. Our ability to reach a definitive collaboration or license agreement with future partners will depend, among other things, upon our assessment of the resources and expertise of such third-party collaborator or licensor and the terms and conditions of the proposed collaboration or license. Further, if we license rights for use in any product candidates we or our collaborators may develop, we may not be able to realize the benefit of such transactions if we are unable to successfully integrate them with our existing operations and company culture.