Xilio Therapeutics, Inc.

Previous wording

Our recurring losses from operations raise substantial doubt regarding our ability to continue as a going concern. If we are unable to raise sufficient additional capital in the near term, we will need to implement additional cost reduction strategies, which could include delaying, limiting, reducing or eliminating both internal and external costs related to our operations and research and development programs.

Current wording

Our recurring losses from operations raise substantial doubt regarding our ability to continue as a going concern. If we are unable to raise sufficient additional capital, we will need to implement additional cost reduction strategies, which could include delaying, limiting, reducing or eliminating both internal and external costs related to our operations and research and development programs.

Previous wording

As of March 31, 2025, we had cash and cash equivalents of $89.1 million. Based on our current operating plans, we anticipate that our cash and cash equivalents as of March 31, 2025 will be sufficient to enable us to fund our operating expenses and capital expenditure requirements into the first quarter of 2026. However, since these amounts are not expected to be sufficient to fund our operations for at least twelve months from the date of issuance of the consolidated financial statements included elsewhere in this Quarterly Report on Form 10-Q, there is substantial doubt about our ability to continue as a going concern. Our future capital requirements and the period for which we expect our existing resources to support our operations may vary from what we expect. Our management has developed plans to continue to fund our operations, which in the near term primarily consist of raising additional capital through one or more of the following: additional equity or debt financings; additional collaborations, partnerships or licensing transactions; or other sources. However, there can be no assurance that we will be able to complete any such transaction on acceptable terms or otherwise, and we may be unable to obtain sufficient additional capital in the near term. If we are not able to secure sufficient additional capital, we will need to implement additional cost reduction strategies, which could include delaying, limiting, further reducing or eliminating both internal and external costs related to our operations and research and development programs. If we are unsuccessful in our efforts in the near term to raise additional capital or in the future to engage in one or more other strategic alternatives, we could be required to liquidate, dissolve or otherwise wind down our operations. Furthermore, our cash forecasts are based on assumptions that may prove to be wrong, and we could use our available capital resources earlier than we currently expect. Please see Note 1 to our consolidated financial statements appearing elsewhere in our Quarterly Report on Form 10-Q for additional information on our assessment.

Current wording

As of June 30, 2025, we had cash and cash equivalents of $121.6 million. Based on our current operating plans, we anticipate that our existing cash and cash equivalents as of June 30, 2025 will be sufficient to enable us to fund our operating expenses and capital expenditure requirements through the end of the third quarter of 2026. However, 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. In addition, 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, tumor-activated 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. These conditions raise substantial doubt about our ability to continue as a going concern. In order to fund our operations, we will need to raise additional capital, which could be obtained through the cash exercise, if any, of the Series B warrants and Series C warrants issued in connection with our June 2025 follow-on public offering, the receipt of milestone payments, option-related fees or other contingent payments under our existing agreements with AbbVie Group Holdings Limited, or AbbVie, and Gilead Sciences, Inc., or Gilead, additional public or private equity offerings, debt financings, additional collaborations, partnerships or licensing arrangements or other sources. However, there can be no assurance that we will receive additional proceeds from the exercise of the common stock warrants or from contingent payments under our existing agreements with Gilead or AbbVie or that the we will be able to complete any such transaction on acceptable terms or otherwise. If we are not able to secure sufficient additional capital when needed, we may need to implement additional cost reduction strategies, which could include delaying, limiting, further reducing or eliminating both internal and external costs related to our operations and research and development programs. Please see Note 1 to our condensed consolidated financial statements appearing elsewhere in our Quarterly Report on Form 10-Q for additional information about our liquidity and going concern. Please see Note 8 to our condensed consolidated financial statements appearing elsewhere in our Quarterly Report on Form 10-Q for additional information about the terms of the warrants we issued in our June 2025 follow-on public offering, including certain potential adjustments to the exercise price of such warrants.

Previous wording

Our future capital requirements, both short-term and long-term, will depend on many factors, including:

Current wording

Our future capital requirements, both short-term and long-term, will depend on many factors, including, but not limited to:

Previous wording

We will require additional capital to sustain our operations. We currently do not have any committed external sources of funds and adequate additional capital may not be available to us 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. We can give no assurance that we will be able to secure additional capital to support our operations, or if such funds are available to us, that such additional funding will be sufficient to meet our needs. These factors raise substantial doubt about our ability to continue as a going concern, and our failure to raise capital, on attractive terms or at all, would have a material adverse effect on our business, results of operations and financial condition.

Current wording

As a result, we will need substantial additional capital to support our continuing operations and pursue our strategy. We currently do not have any committed external sources of funds and adequate additional capital may not be available to us 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. We can give no assurance that we will be able to secure additional capital to support our operations, or if such funds are available to us, that such additional funding will be sufficient to meet our needs. These factors raise substantial

Previous wording

Raising additional capital may cause dilution to our stockholders, restrict our operations or require us to relinquish rights to product candidates or our technology.

Current wording

Raising additional capital may cause dilution to our stockholders, restrict our operations or require us to relinquish rights to product candidates or our technology. In addition, the issuance of shares of common stock upon the exercise of our outstanding prefunded warrants or common stock warrants will result in immediate and substantial dilution to our existing stockholders.

Previous wording

Unless and until we can generate a substantial amount of product revenue, we expect to seek additional capital through a combination of public or private equity offerings, debt, collaborations, licensing arrangements or other sources. Our issuance of additional securities, whether equity or debt, or the possibility of such issuance, may cause the market price of our common stock to decline, and our stockholders may not agree with our plans for additional capital or the terms of such capital. To the extent that we raise additional capital through the sale of equity or convertible debt securities, our stockholders’ ownership interest will be diluted, and the terms of these securities may include liquidation or other preferences that adversely affect the rights of our existing stockholders. For example, when we issue shares of common stock upon the exercise of our outstanding prefunded warrants, or if we issue additional shares of our common stock in one or more “at-the-market,” or ATM, offerings, our existing stockholders will suffer dilution. In addition, as a condition to providing additional funds to us, Gilead and AbbVie received, and future investors may receive, rights superior to those of existing stockholders. To the extent that we incur additional indebtedness, we would become obligated to make payments to repay the loan balance with interest. The incurrence of any additional indebtedness would result in additional payment obligations and is likely to involve restrictive covenants limiting our flexibility in conducting future business activities, and, in the event of insolvency, would be repaid before holders of our equity securities received any distribution of our corporate assets. Additionally, in raising funds through our collaborations and licensing arrangements with third parties, we have had to, and may in the future need to, relinquish valuable rights, partially or fully, to our technologies, future revenue streams, research programs or product candidates and grant licenses on terms unfavorable to us. In addition, securing additional capital would require a substantial amount of time and attention from our management and may divert a disproportionate amount of their attention away from day-to-day activities, which may adversely affect our management’s ability to oversee the development of our product candidates.

Current wording

Unless and until we can generate a substantial amount of product revenue, we expect to seek additional capital through a combination of public or private equity offerings, debt, collaborations, licensing arrangements or other sources. Our issuance of additional securities, whether equity or debt, or the possibility of such issuance, may cause the market price of our common stock to decline, and our stockholders may not agree with our plans for additional capital or the terms of such capital. To the extent that we raise additional capital through the sale of equity or convertible debt securities, our stockholders’ ownership interest will be diluted, and the terms of these securities may include liquidation or other preferences that adversely affect the rights of our existing stockholders. In addition, the issuance of shares of common stock upon the exercise of our outstanding prefunded warrants or common stock warrants will result in immediate and substantial dilution to our existing stockholders. Similarly, if we issue additional shares of our common stock in one or more public or private offerings in the future, our existing stockholders will suffer further dilution. In addition, as a condition to providing additional funds to us, Gilead and AbbVie received rights superior to those of existing stockholders, and in connection with the issuance of prefunded warrants and common stock warrants in June 2025, we agreed to specified restrictions on our future equity issuances, such as minimum purchase price requirements, unless we obtain the requisite prior approval of the warrant holders. Future investors may similarly receive rights that are superior to those of existing investors or which place restrictions on our future equity issuances. In addition, the incurrence of any indebtedness would result in additional payment obligations and is likely to involve restrictive covenants limiting our flexibility in conducting future business activities, and, in the event of insolvency, would be repaid before holders of our equity securities received any distribution of our corporate assets. Further, in raising funds through our collaborations and licensing arrangements with third parties, we have had to, and may in the future need to, relinquish valuable rights, partially or fully, to our technologies, future revenue streams, research programs or product candidates and grant licenses on terms unfavorable to us. In addition, securing additional capital would require a substantial amount of time and attention from our management and may divert a disproportionate amount of their attention away from day-to-day activities, which may adversely affect our management’s ability to oversee the development of our product candidates.

Previous wording

If it appears to the Nasdaq Staff that we will not be able to cure the deficiency during the second compliance period 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. We expect that our common stock would remain listed pending the panel’s decision. 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.

Current wording

If it appears to the Nasdaq Staff that we will not be able to cure the deficiency during the second compliance period 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.

Previous wording

We have incurred significant operating losses since our inception and have not yet generated any revenue from the sale of products. If our product candidates are not successfully developed and approved, we may never generate any revenue from product sales. Our net losses were $13.3 million and $17.2 million for the three months ended March 31, 2025 and 2024, respectively. As of March 31, 2025, we had an accumulated deficit of $397.0 million. To date, we have financed our operations primarily from proceeds raised through private placements of preferred units, convertible preferred stock, common stock and prefunded warrants; a debt financing; our initial public offering, or IPO, of common stock in October 2021; upfront payments under our collaboration and license agreements with AbbVie and Gilead; and sales of common stock in “at-the-market” offerings. We have devoted substantially all of our financial resources and efforts to research and development. We are still in the early stages of development of our tumor-activated, or masked, product candidates, and we have not completed clinical development for our clinical-stage product candidates, vilastobart (anti-CTLA-4) and XTX301 (IL-12). We expect to continue to incur significant expenses and operating losses for the foreseeable future, particularly to the extent we:

Current wording

Since inception, we have incurred significant operating losses, including net losses of $29.1 million and $31.1 million for the six months ended June 30, 2025 and 2024, respectively, and a net loss of $58.2 million for the year ended December 31, 2024. As of June 30, 2025, we had an accumulated deficit of $412.9 million. As of June 30, 2025, we had cash and cash equivalents of $121.6 million. To date, we have financed our operations primarily from proceeds raised through private placements of preferred units, convertible preferred stock, common stock and prefunded warrants; sales of common stock in our initial public offering, or IPO, and through “at-the-market” offerings; the sale of prefunded warrants and common stock warrants in a follow-on public offering; and upfront 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. 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:

Previous wording

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.

Current wording

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

Previous wording

Our business and future success is highly dependent on our ability to obtain regulatory approval for, and if approved, successfully launch and commercialize, our current product candidates, including our clinical-stage, tumor-activated product candidates: vilastobart and XTX301. We are currently evaluating vilastobart in combination with atezolizumab (Tecentriq®) in Phase 1C combination dose escalation in patients with advanced solid tumors and in a Phase 2 clinical trial evaluating the combination in patients with metastatic microsatellite stable colorectal cancer, or MSS CRC. We are currently evaluating XTX301 in a Phase 1 clinical trial. We also have a portfolio of programs that are in even earlier stages of preclinical development and may never advance to clinical-stage development, including XTX501, our masked PD-

Current wording

Our business and future success is highly dependent on our ability to obtain regulatory approval for, and if approved, successfully launch and commercialize, our current product candidates, including our clinical-stage, tumor-activated product candidates: vilastobart and XTX301. We are currently evaluating vilastobart in combination with atezolizumab (Tecentriq®) in Phase 1C combination dose escalation in patients with advanced solid tumors and in a Phase 2 clinical

Previous wording

1/IL-2 bispecific, which is designed to selectively stimulate PD-1 positive antigen-experienced T cells and enhance their function and is currently advancing in initial IND-enabling activities, and our preclinical programs for masked T cell engagers targeting prostate-specific membrane antigen, or PSMA, claudin 18.2, or CLDN18.2, and six-transmembrane epithelial antigen of prostate 1, or STEAP1.

Current wording

trial evaluating the combination in patients with metastatic microsatellite stable colorectal cancer, or MSS CRC. XTX301 has completed enrollment in Phase 1A monotherapy dose escalation and continues to enroll patients in Phase 1B monotherapy dose expansion of our ongoing Phase 1 clinical trial in patients with advanced solid tumors under our exclusive license agreement with Gilead. We also have a portfolio of programs that are in even earlier stages of preclinical development and may never advance to clinical-stage development, including XTX501, our masked PD-1/IL-2 bispecific, which is designed to selectively stimulate PD-1 positive antigen-experienced T cells and enhance their function and is currently advancing in initial IND-enabling activities, and our wholly owned preclinical programs for masked T cell engagers targeting prostate-specific membrane antigen, or PSMA, claudin 18.2, or CLDN18.2, and six-transmembrane epithelial antigen of prostate 1, or STEAP1, as well as an additional masked T cell engager program in collaboration with AbbVie.

Previous wording

The success of our business, including our ability to finance our company and generate any revenue in the future, will primarily depend on the successful development, regulatory approval and commercialization of our current and any future product candidates, which may never occur. However, given our early stage of development, it will be years before we are able to demonstrate the safety and efficacy of a treatment sufficient to warrant approval for commercialization, and we may never be able to do so. If we are unable to develop, or obtain regulatory approval for, or, if approved, successfully commercialize our current or any future product candidates, we may not be able to generate sufficient revenue to continue our business.

Current wording

The success of our business, including our ability to finance our company and generate any revenue in the future, will primarily depend on the successful development, regulatory approval and commercialization of our current and any future product candidates, which may never occur. However, given our early stage of development, it will be years before we are able to demonstrate the safety and efficacy of a treatment sufficient to warrant approval for commercialization, and we may never be able to do so. If we are unable to develop, or obtain regulatory approval for, or, if approved, successfully

Previous wording

The risk of failure for our current and any future product candidates is high. It is impossible to predict when or if any of our product candidates will successfully complete preclinical studies or clinical trials evaluating their safety and effectiveness in humans or will ultimately receive regulatory approval. To obtain the requisite regulatory approvals to market and sell any of our product candidates, we must demonstrate through extensive preclinical studies and clinical trials that our product candidates are safe and effective in humans for use in each target indication. Preclinical and clinical testing is expensive and can take many years to complete, and the outcome is inherently uncertain. Failure can occur at any time during the preclinical or clinical trial process. The outcome of preclinical testing and early clinical trials may not be predictive of the results of later clinical trials, and interim results of a clinical trial do not necessarily predict final results. In particular, while we have conducted certain preclinical studies for each of our clinical stage product candidates, we do not know whether these product candidates will perform in our clinical trials as they have performed in these prior preclinical studies. Similarly, there can be no assurance that early, interim or preliminary clinical data or results will be predictive of or replicated in future clinical data or results, including without limitation, the Phase 2 data for vilastobart in combination with atezolizumab and the Phase 1 data for XTX301 reported to date. Many companies in the biopharmaceutical and biotechnology industries have suffered significant setbacks in late-stage clinical trials after achieving positive results in early-stage development and we cannot be certain that we will not face similar setbacks. These setbacks have been caused by, among other things, preclinical findings made while clinical trials were underway, or safety or efficacy observations made in preclinical studies and clinical trials, including previously unreported adverse events, or AEs. Moreover, preclinical and clinical data are often susceptible to varying interpretations and analyses, and many companies that have believed their product candidates performed satisfactorily in preclinical studies and clinical trials have nonetheless failed to obtain marketing approval of their products.

Current wording

The risk of failure for our current and any future product candidates is high. It is impossible to predict when or if any of our product candidates will successfully complete preclinical studies or clinical trials evaluating their safety and effectiveness in humans or will ultimately receive regulatory approval. To obtain the requisite regulatory approvals to market and sell any of our product candidates, we must demonstrate through extensive preclinical studies and clinical trials that our product candidates are safe and effective in humans for use in each target indication. Preclinical and clinical testing is expensive and can take many years to complete, and the outcome is inherently uncertain. Failure can occur at any time during the preclinical or clinical trial process. The outcome of preclinical testing and early clinical trials may not be predictive of the results of later clinical trials, and interim results of a clinical trial do not necessarily predict final results. In particular, while we have conducted certain preclinical studies for each of our clinical stage product candidates, we do not know whether these product candidates will perform in our clinical trials as they have performed in these prior preclinical studies. Similarly, there can be no assurance that early, interim or preliminary clinical data or results will be predictive of or replicated in future clinical data or results, including without limitation, the Phase 1/2 data for vilastobart in combination with atezolizumab and the Phase 1 data for XTX301 reported to date. Many companies in the biopharmaceutical and biotechnology industries have suffered significant setbacks in late-stage clinical trials after achieving positive results in early-stage development and we cannot be certain that we will not face similar setbacks. These setbacks have been caused by, among other things, preclinical findings made while clinical trials were underway, or safety or efficacy observations made in preclinical studies and clinical trials, including previously unreported adverse events, or AEs. Moreover, preclinical and clinical data are often susceptible to varying interpretations and analyses, and many companies that have believed their product candidates performed satisfactorily in preclinical studies and clinical trials have nonetheless failed to obtain marketing approval of their products.

Previous wording

cannot guarantee that any clinical trials, including our Phase 2 clinical trial evaluating vilastobart in combination with atezolizumab or our Phase 1 clinical trial evaluating XTX301 as a monotherapy, will be conducted as planned or completed on schedule, if at all. For example, in the first quarter of 2024, we announced plans to discontinue further investment in XTX202, our tumor-activated IL-2, as a monotherapy. We may experience numerous unforeseen events leading up to, during or as a result of clinical trials that could delay or prevent the initiation or completion of a clinical trial or our ability to receive marketing approval or commercialize our product candidates, including:

Current wording

Before obtaining marketing approval from regulatory authorities for the sale of our product candidates, we must conduct extensive clinical trials to demonstrate the safety and efficacy of the product candidate for its intended indications. We cannot guarantee that any clinical trials, including our Phase 2 clinical trial evaluating vilastobart in combination with atezolizumab or our Phase 1 clinical trial evaluating XTX301 as a monotherapy, will be conducted as planned or completed on schedule, if at all. We may experience numerous unforeseen events leading up to, during or as a result of clinical trials that could delay or prevent the initiation or completion of a clinical trial or our ability to receive marketing approval or commercialize our product candidates, including:

Previous wording

From time to time, we may publish interim top-line or preliminary data from our clinical trials. For example, we most recently reported initial data from our Phase 2 clinical trial for vilastobart in combination with atezolizumab in January 2025, and we plan to report additional Phase 2 data in the middle of 2025, and we most recently reported safety data from our Phase 1 clinical trial for XTX301 in December 2024. Preliminary and interim data from clinical trials that we may complete are subject to the risk that one or more of the clinical outcomes may materially change as patient enrollment continues and more patient data become available. Preliminary or “top-line” data also remain subject to audit and verification procedures that may result in the final data being materially different from the preliminary data previously published. As a result, interim and preliminary data should be viewed with caution until the final data are available. Adverse differences between preliminary or interim data and final data could significantly harm our business prospects.

Current wording

From time to time, we may publish interim top-line or preliminary data from our clinical trials. For example, we most recently reported updated data from our Phase 2 clinical trial for vilastobart in combination with atezolizumab in May 2025, and we most recently reported safety data from our Phase 1 clinical trial for XTX301 in December 2024. Preliminary and interim data from clinical trials that we may complete are subject to the risk that one or more of the clinical outcomes may materially change as patient enrollment continues and more patient data become available. Preliminary or “top-line” data also remain subject to audit and verification procedures that may result in the final data being materially different from the preliminary data previously published. As a result, interim and preliminary data should be viewed with caution until the final data are available. Adverse differences between preliminary or interim data and final data could significantly harm our business prospects.

Previous wording

We intend to develop our clinical-stage product candidates, and likely other future product candidates, in combination with third-party cancer drugs, which may be either approved or unapproved. For example, we are currently evaluating vilastobart in combination with atezolizumab (Tecentriq®) in Phase 1 combination dose escalation in patients with advanced solid tumors and in a Phase 2 clinical trial evaluating the combination in patients with MSS CRC. Our ability to develop and ultimately commercialize our current product candidates, and any future product candidates, used in combination with third-party drugs will depend on our ability to access such drugs on commercially reasonable terms for clinical trials and their availability for use with our commercialized product, if approved. We cannot be certain that current or potential future commercial relationships will provide us with a steady supply of such drugs on commercially reasonable terms or at all. Any failure to maintain or enter into new successful commercial relationships, or the expense of purchasing such third-party drugs in the market, may delay our development timelines, increase our costs and jeopardize our ability to develop our current product candidates and any future product candidates as commercially viable therapies. If any of these occur, our business, financial condition, operating results or prospects may be materially harmed.

Current wording

We intend to develop our clinical-stage product candidates, and likely other future product candidates, in combination with third-party cancer drugs, which may be either approved or unapproved. For example, we are currently evaluating vilastobart in combination with atezolizumab (Tecentriq®) in Phase 1 combination dose escalation in patients with advanced solid tumors and in a Phase 2 clinical trial evaluating the combination in patients with metastatic MSS CRC. Our ability to develop and ultimately commercialize our current product candidates, and any future product candidates, used in combination with third-party drugs will depend on our ability to access such drugs on commercially reasonable terms for clinical trials and their availability for use with our commercialized product, if approved. We cannot be certain that current or potential future commercial relationships will provide us with a steady supply of such drugs on commercially reasonable terms or at all. Any failure to maintain or enter into new successful commercial relationships, or the expense of purchasing such third-party drugs in the market, may delay our development timelines, increase our costs and jeopardize our ability to develop our current product candidates and any future product candidates as commercially viable therapies. If any of these occur, our business, financial condition, operating results or prospects may be materially harmed.

Previous wording

If we are able to obtain marketing approval, the FDA or comparable foreign regulatory authorities may require that products used in conjunction with each other be cross labeled for combined use. To the extent that we do not have rights to the third-party drug, this may require us to work with such third party to satisfy such a requirement. We would also continue to be subject to the risks that the FDA or comparable foreign regulatory authorities could revoke approval of the third-party drug used in combination with our product candidate or that safety, efficacy, manufacturing or supply issues

Current wording

If we are able to obtain marketing approval, the FDA or comparable foreign regulatory authorities may require that products used in conjunction with each other be cross labeled for combined use. To the extent that we do not have rights to the third-party drug, this may require us to work with such third party to satisfy such a requirement. We would also continue to be subject to the risks that the FDA or comparable foreign regulatory authorities could revoke approval of the third-party drug used in combination with our product candidate or that safety, efficacy, manufacturing or supply issues could arise with such drug. Similarly, if the third-party drugs we use in combination with our product candidates are replaced as the standard of care for the indications we choose for any of our product candidates, the FDA or comparable foreign regulatory authorities may require us to conduct additional clinical trials. The occurrence of any of these risks could result in our own products, if approved, being removed from the market or being less successful commercially.

Previous wording

The success of our business depends primarily upon our ability to discover, develop and commercialize products based on our technological approaches. While we have had favorable preclinical and early clinical results related to our clinical-stage product candidates, vilastobart and XTX301, we have not yet succeeded and may not succeed in demonstrating efficacy and safety for any product candidates in current or future clinical trials or in obtaining marketing approval thereafter. We rely on matrix metalloproteases, or MMPs, to activate our molecules within the tumor microenvironment. If MMP activity in human tumors is not sufficient to cleave the masking protein domain, the potential efficacy of our

Current wording

The success of our business depends primarily upon our ability to discover, develop and commercialize products based on our technological approaches. While we have had favorable preclinical and early clinical results related to our clinical-stage product candidates, vilastobart and XTX301, we have not yet succeeded and may not succeed in demonstrating efficacy and safety for any product candidates in current or future clinical trials or in obtaining marketing approval thereafter. We rely on matrix metalloproteases, or MMPs, to activate our molecules within the tumor microenvironment. If MMP activity in human tumors is not sufficient to cleave the masking protein domain, the potential efficacy of our product candidates would be limited. We have no assurance that our product candidates will successfully progress through clinical development and ultimately marketing approval. We have invested substantially all of our efforts and financial resources in developing our initial product candidates and our future success is highly dependent on the outcome of our ongoing clinical trials and the successful development of our technology and product candidates.

Previous wording

Although the clinical trial process is designed to identify and assess potential side effects, it is always possible that a drug, even after regulatory approval, may exhibit unforeseen side effects. If any of our product candidates were to cause adverse side effects during clinical trials or after approval thereof, we may be exposed to substantial liabilities. Physicians and patients may not comply with any warnings that identify known potential adverse effects and patients who should not use our product candidates. If we cannot successfully defend ourselves against product liability claims, we may incur substantial liabilities or be required to limit or cease the development or commercialization of our product candidates or

Current wording

side effects during clinical trials or after approval thereof, we may be exposed to substantial liabilities. Physicians and patients may not comply with any warnings that identify known potential adverse effects and patients who should not use our product candidates. If we cannot successfully defend ourselves against product liability claims, we may incur substantial liabilities or be required to limit or cease the development or commercialization of our product candidates or any products for which we may have received marketing approval. Even a successful defense would require significant financial and management resources. Regardless of the merits or eventual outcome, liability claims may result in:

Previous wording

Given the nature of biologics manufacturing, there is a risk of contamination during manufacturing. Any contamination could materially harm our ability to produce product candidates on schedule and could harm our results of operations and cause reputational damage. In the event that raw materials required in our manufacturing process need to be derived from biologic sources, they may be difficult to procure and may be subject to contamination or recall.

Current wording

Given the nature of biologics manufacturing, there is a risk of contamination during manufacturing. Any contamination could materially harm our ability to produce product candidates on schedule and could harm our results of operations and

Previous wording

claims, insufficient inventory or potentially delay progression of our preclinical or clinical development of any product candidates we may develop. If we successfully develop product candidates, we may encounter problems achieving adequate quantities and quality that meet FDA, European Medicines Agency, or EMA, or other comparable applicable foreign standards or specifications with consistent and acceptable production yields and costs. The ability to scale our manufacturing and maintain the manufacturing process at the same levels of quality and efficiency that we are currently manufacturing is yet to be tested. If we or our third-party CDMO is unable to scale our manufacturing and meet the same levels of quality and efficiency, or provide sufficient manufacturing campaign slots to generate materials, we may not be able to supply the required number of doses for clinical trials or commercial supply. A material shortage, contamination event or manufacturing failure in the manufacture of any product candidate we may develop or other adverse impact or disruption in the commercial manufacturing or the production of clinical material could materially harm our development timelines and our business, financial condition, results of operations and prospects.

Current wording

Problems with the manufacturing process, even minor deviations from the normal process, could result in product defects, out-of-specification analytical results or manufacturing failures that result in lot failures, product recalls, product liability claims, insufficient inventory or potentially delay progression of our preclinical or clinical development of any product candidates we may develop. If we successfully develop product candidates, we may encounter problems achieving adequate quantities and quality that meet FDA, European Medicines Agency, or EMA, or other comparable applicable foreign standards or specifications with consistent and acceptable production yields and costs. The ability to scale our manufacturing and maintain the manufacturing process at the same levels of quality and efficiency that we are currently manufacturing is yet to be tested. If we or our third-party CDMO is unable to scale our manufacturing and meet the same levels of quality and efficiency, or provide sufficient manufacturing campaign slots to generate materials, we may not be able to supply the required number of doses for clinical trials or commercial supply. A material shortage, contamination event or manufacturing failure in the manufacture of any product candidate we may develop or other adverse impact or disruption in the commercial manufacturing or the production of clinical material could materially harm our development timelines and our business, financial condition, results of operations and prospects.

Previous wording

Currently, we depend on WuXi Biologics (Hong Kong) Limited, or WuXi Biologics, for developing the manufacturing processes required to supply our product candidates. We cannot ensure that this manufacturer will remain in business or have sufficient capacity or supply to meet our needs. Our use of a single manufacturer exposes us to several risks, including price increases or manufacturing delays beyond our control. WuXi Biologics is based in and has significant operations in

Current wording

Currently, we depend on WuXi Biologics (Hong Kong) Limited, or WuXi Biologics, for developing the manufacturing processes required to supply our product candidates. We cannot ensure that this manufacturer will remain in business or have sufficient capacity or supply to meet our needs. Our use of a single manufacturer exposes us to several risks, including price increases or manufacturing delays beyond our control. WuXi Biologics is based in and has significant operations in China, where our product candidates are manufactured, which subjects us to additional risks including those related to U.S. export control laws, potential sanctions or other trade restrictions imposed by the U.S. government. Moreover, reliance on third-party manufacturers generally entails risks to which we would not be subject if we manufactured the product candidates ourselves, including:

Previous wording

These factors could cause the delay of clinical trials, regulatory submissions, required approvals or commercialization of our product candidates, cause us to incur higher costs and prevent us from commercializing our products successfully. Furthermore, if our suppliers fail to meet contractual requirements, and we are unable to secure one or more replacement suppliers capable of production at a substantially equivalent cost, our clinical trials may be delayed, or we could lose potential revenue or market share with respect to any product that has received marketing approval.

Current wording

These factors could cause the delay of clinical trials, regulatory submissions, required approvals or commercialization of our product candidates, cause us to incur higher costs and prevent us from commercializing our products successfully. Furthermore, if our suppliers fail to meet contractual requirements, and we are unable to secure one or more replacement

Previous wording

including the passage of the People’s Republic of China Biosecurity law, which became effective on April 15, 2021, and subsequent legislation that China or the United States may adopt in the future, or other events in China could disrupt our ability to continue to rely upon CROs, CDMOs, collaborators, manufacturers or other third parties with whom we conduct business now or in the future. Any disruption in China or the United States that significantly impacts such third parties, including services provided by CROs for our research and development programs, or our manufacturers’ ability to produce and export raw or manufactured materials in adequate quantities to meet our needs, could impair our ability to operate our business on a day-to-day basis and impede, delay, limit or prevent the research, development or commercialization of our current and future products or product candidates. In addition, for any activities conducted in China, we are exposed to the possibility of product supply disruption and increased costs in the event of changes in the policies of the U.S. or Chinese governments, political unrest or unstable economic or geopolitical conditions, including sanctions in China or against certain Chinese companies; changes in U.S. export laws or the imposition by the United States of trade barriers; sanctions; limitations on uses of U.S. government executive agency contract, grant or loan funds; or other restrictions on doing business with certain Chinese companies, including WuXi Biologics, which could have a material adverse effect on our business. Additionally, we may be exposed to fluctuations in the value of the local currency in China for goods and services. Our costs for any of these services or activities could also increase as a result of future appreciation of the local currency in China or increased labor costs if the demand for skilled laborers increases and/or the availability of skilled labor declines in China.

Current wording

We have relied on WuXi Biologics in China to manufacture and supply certain raw materials used in our product candidates, and we expect to continue to use WuXi Biologics as our CDMO for such purposes. A natural disaster, epidemic or pandemic, such as the COVID-19 pandemic, trade war, political unrest, economic conditions, changes in legislation, including the passage of the People’s Republic of China Biosecurity law, which became effective on April 15, 2021, and subsequent legislation that China or the United States may adopt in the future, or other events in China could disrupt our ability to continue to rely upon CROs, CDMOs, collaborators, manufacturers or other third parties with whom we conduct business now or in the future. Any disruption in China or the United States that significantly impacts such third parties, including services provided by CROs for our research and development programs, or our manufacturers’ ability to produce and export raw or manufactured materials in adequate quantities to meet our needs, could impair our ability to operate our business on a day-to-day basis and impede, delay, limit or prevent the research, development or commercialization of our current and future products or product candidates. In addition, for any activities conducted in China, we are exposed to the possibility of product supply disruption and increased costs in the event of changes in the policies of the U.S. or Chinese governments, political unrest or unstable economic or geopolitical conditions, including sanctions in China or against certain Chinese companies; changes in U.S. export laws or the imposition by the United States of trade barriers; sanctions; limitations on uses of U.S. government executive agency contract, grant or loan funds; or other restrictions on doing business with certain Chinese companies, including WuXi Biologics, which could have a material adverse effect on our business. Additionally, we may be exposed to fluctuations in the value of the local currency in China for goods and services. Our costs for any of these services or activities could also increase as a result of future appreciation of the local currency in China or increased labor costs if the demand for skilled laborers increases and/or the availability of skilled labor declines in China.

Previous wording

Any third-party CDMOs and suppliers we engage will also be subject to these and other environmental, health and safety laws and regulations. Liabilities they incur pursuant to these laws and regulations could result in significant costs or an

Current wording

Any third-party CDMOs and suppliers we engage will also be subject to these and other environmental, health and safety laws and regulations. Liabilities they incur pursuant to these laws and regulations could result in significant costs or an interruption in operations, which could have a material adverse effect on our business, financial condition, results of operations and prospects.

Previous wording

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 XTX301, our tumor activated 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 XTX301 and the rest of our IL-12 program, it will have sole decision-making authority with respect to the continued development and future

Current wording

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 XTX301, our tumor activated 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

Previous wording

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.

Current wording

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 XTX301 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.

Previous wording

We are developing our most advanced clinical-stage, tumor-activated product candidates for the treatment of cancer and have not completed clinical development or received marketing approval for either vilastobart or XTX301. There are already a variety of available therapies marketed for cancer and some of the currently approved therapies are branded and subject to patent protection, and others are available on a generic basis. Many of these approved therapies are well-established and widely accepted by physicians, patients and third-party payors. Insurers and other third-party payors may also encourage the use of generic products. We expect that if our product candidates are approved, they will be priced at a significant premium over competitive generic products. This may make it difficult for us to achieve our business strategy of using our product candidates in combination with existing therapies or replacing existing therapies with our product candidates. Competition may further increase with advances in the commercial applicability of technologies and greater availability of capital for investment in these industries.

Current wording

We are developing our most advanced clinical-stage, tumor-activated product candidates for the treatment of cancer and have not completed clinical development or received marketing approval for either vilastobart or XTX301. There are already a variety of available therapies marketed for cancer and some of the currently approved therapies are branded and subject to patent protection, and others are available on a generic basis. Many of these approved therapies are well-established and widely accepted by physicians, patients and third-party payors. Insurers and other third-party payors may also encourage the use of generic products. We expect that if our product candidates are approved, they will be priced at a significant premium over competitive generic products. This may make it difficult for us to achieve our business strategy of using our product candidates in combination with existing therapies or replacing existing therapies with our product

Previous wording

With respect to XTX301, currently there are no IL-12 therapies approved for the treatment of cancer. However, we are aware of several other companies that have modified IL-12 delivery programs in development, including Cullinan Management Inc., Dragonfly Therapeutics, Inc., ImmunityBio, Inc., Mural Oncology, Inc., PDS Biotechnology Corporation, Philogen S.p.A., Sonnet BioTherapeutics, Werewolf Therapeutics, Inc., Xencor Inc. and Zymeworks Inc.

Current wording

With respect to XTX301, currently there are no IL-12 therapies approved for the treatment of cancer. However, we are aware of several other companies that have modified IL-12 delivery programs in development, including Cullinan Management Inc., Dragonfly Therapeutics, Inc., ImmunityBio, Inc., Shanghai KangaBio Co., Ltd., Mural Oncology, Inc., PDS Biotechnology Corporation, Philogen S.p.A., Sonnet BioTherapeutics, Werewolf Therapeutics, Inc., Xencor Inc. and Zymeworks Inc.

Previous wording

With respect to our most advanced research-stage product candidate, XTX501, currently, there are no bispecific PD-1 targeted IL-2 therapies approved for the treatment of cancer. However, if we continue to advance development of XTX501, we are aware of several other companies that have modified PD-1 targeted IL-2 bispecific antibodies in development, including Anaveon AG, Bright Peak Therapeutics, Inc., Innovent Biologics, Inc., Regeneron Pharmaceuticals, Inc. and Roche.

Current wording

With respect to our most advanced research-stage product candidate, XTX501, currently, there are no bispecific PD-1 targeted IL-2 therapies approved for the treatment of cancer. However, if we continue to advance development of XTX501, we are aware of several other companies that have modified PD-1 targeted IL-2 bispecific antibodies in development, including Anaveon AG, Bright Peak Therapeutics, Inc., Innovent Biologics, Inc., Regeneron Pharmaceuticals, Inc., Roche, and Teva Pharmaceutical Industries, Ltd.

Previous wording

With respect to our masked T cell engager programs, currently there are no T cell engager therapies targeting PSMA, CLDN18.2 or STEAP1 approved for the treatment of cancer. We are aware of several other companies that have masked T cell engager programs in development for PSMA, including Janux Therapeutics, Inc. and Vir Biotechnology, Inc. To our knowledge, there are no companies currently developing masked T cell engager programs for CLDN18.2 or STEAP1. However, we are aware of several companies developing non-masked T cell engager programs for CLDN18.2, including Amgen Inc., Innovent Biologics, Inc., Transcenta Holding Ltd. and Zai Lab Limited, and for STEAP1, including Amgen Inc., Nutcracker Therapeutics and Xencor Inc.

Current wording

With respect to our masked T cell engager programs, currently there are no T cell engager therapies targeting PSMA, CLDN18.2 or STEAP1 approved for the treatment of cancer. We are aware of several other companies that have masked T cell engager programs in development for PSMA, including Janux Therapeutics, Inc. and Vir Biotechnology, Inc. We are aware of one other company, Werewolf Therapeutics, Inc., currently developing a masked T cell engager program for STEAP1. To our knowledge, there are no companies currently developing a masked T cell engager program for CLDN18.2. However, we are aware of several companies developing non-masked T cell engager programs for CLDN18.2, including Amgen Inc., Innovent Biologics, Inc., Transcenta Holding Ltd. and Zai Lab Limited, and for STEAP1, including Amgen Inc., Nutcracker Therapeutics and Xencor Inc.

Previous wording

For planning purposes, we sometimes estimate the timing of the accomplishment of various scientific, clinical, regulatory and other product development objectives. These milestones may include our expectations regarding the commencement or completion of scientific studies and clinical trials, the submission of regulatory filings or commercialization objectives. From time to time, we may publicly announce the expected timing of some of these milestones, such as the release of clinical trial data, the completion of an ongoing clinical trial, the initiation of other clinical trials, receipt of regulatory approval or the commercial launch of a product. The achievement of many of these milestones may be outside of our control. All of these milestones are based on a variety of assumptions which may cause the timing of achievement of the milestones to vary considerably from our estimates, including:

Current wording

or completion of scientific studies and clinical trials, the submission of regulatory filings or commercialization objectives. From time to time, we may publicly announce the expected timing of some of these milestones, such as the release of clinical trial data, the completion of an ongoing clinical trial, the initiation of other clinical trials, receipt of regulatory approval or the commercial launch of a product. The achievement of many of these milestones may be outside of our control. All of these milestones are based on a variety of assumptions which may cause the timing of achievement of the milestones to vary considerably from our estimates, including:

Previous wording

Third-party payors increasingly are challenging prices charged for pharmaceutical products and services, and many third-party payors may refuse to provide coverage and reimbursement for particular drugs or biologics when an equivalent generic drug, biosimilar or a less expensive therapy is available. It is possible that a third-party payor may consider our product candidates as substitutable and only offer to reimburse patients for the less expensive product. Even if we show improved efficacy or improved convenience of administration with our product candidates, pricing of existing third-party therapeutics may limit the amount we will be able to charge for our product candidates. These payors may deny or revoke the reimbursement status of a given product or establish prices for new or existing marketed products at levels that are too low to enable us to realize an appropriate return on our investment in our product candidates, if approved. Even if our product candidates are approved and we obtain coverage for our product candidates by a third-party payor, such products may not be considered cost-effective and/or the resulting reimbursement payment rates may be insufficient or may require co-payments that patients find unacceptably high. Interim reimbursement levels for new medicines, if applicable, may also not be sufficient to cover our costs and may not be made permanent. Net prices for medicines may be reduced by mandatory discounts or rebates required by government healthcare programs or private payors and by any future relaxation of laws that presently restrict imports of medicines from countries where they may be sold at lower prices than in the United States. If reimbursement is not available or is available only at limited levels, we may not be able to successfully commercialize our product candidates, if approved, and may not be able to obtain a satisfactory financial return on our product candidates.

Current wording

Third-party payors increasingly are challenging prices charged for pharmaceutical products and services, and many third-party payors may refuse to provide coverage and reimbursement for particular drugs or biologics when an equivalent generic drug, biosimilar or a less expensive therapy is available. It is possible that a third-party payor may consider our product candidates as substitutable and only offer to reimburse patients for the less expensive product. Even if we show improved efficacy or improved convenience of administration with our product candidates, pricing of existing third-party therapeutics may limit the amount we will be able to charge for our product candidates. These payors may deny or revoke the reimbursement status of a given product or establish prices for new or existing marketed products at levels that are too low to enable us to realize an appropriate return on our investment in our product candidates, if approved. Even if our product candidates are approved and we obtain coverage for our product candidates by a third-party payor, such products may not be considered cost-effective and/or the resulting reimbursement payment rates may be insufficient or may require co-payments that patients find unacceptably high. Interim reimbursement levels for new medicines, if applicable, may also not be sufficient to cover our costs and may not be made permanent. Net prices for medicines may be reduced by mandatory discounts or rebates required by government healthcare programs or private payors and by any future relaxation of laws that presently restrict imports of medicines from countries where they may be sold at lower prices than in the United States.

Previous wording

Patent positions of life sciences companies can be uncertain and involve complex factual and legal questions and have in recent years been the subject of much litigation. No consistent policy governing the scope of claims allowable in the field of engineered therapeutic proteins has emerged in the United States. The scope of patent protection in jurisdictions outside of the United States is also uncertain. Changes in either the patent laws or their interpretation in any jurisdiction that we seek patent protection may diminish our ability to protect our inventions, maintain and enforce our intellectual property rights; and, more generally, may affect the value of our intellectual property, including the narrowing of the scope of our patents and any that we may license. Under the Leahy-Smith America Invents Act enacted in 2011, or the AIA, the United States moved to a first-to-file system in early 2013 (whereby, assuming the other requirements for patentability are met, the first to file a patent application is entitled to the patent), from the previous system under which the first to make a claimed invention was entitled to the patent. Publications of discoveries in the scientific and academic literature often lag behind the actual discoveries, and patent applications in the United States and other jurisdictions are typically not published until 18 months after filing, or in some cases not at all. Therefore, we cannot be certain that we were the first to file for patent protection on the inventions claimed in our patents or pending patent applications. Furthermore, for U.S.

Current wording

Patent positions of life sciences companies can be uncertain and involve complex factual and legal questions and have in recent years been the subject of much litigation. No consistent policy governing the scope of claims allowable in the field of engineered therapeutic proteins has emerged in the United States. The scope of patent protection in jurisdictions outside of the United States is also uncertain. Changes in either the patent laws or their interpretation in any jurisdiction that we seek patent protection may diminish our ability to protect our inventions, maintain and enforce our intellectual property rights; and, more generally, may affect the value of our intellectual property, including the narrowing of the scope of our patents and any that we may license. Under the Leahy-Smith America Invents Act enacted in 2011, or the AIA, the United States moved to a first-to-file system in early 2013 (whereby, assuming the other requirements for patentability are met, the first to file a patent application is entitled to the patent), from the previous system under which the first to make a claimed invention was entitled to the patent. Publications of discoveries in the scientific and academic literature often lag behind the actual discoveries, and patent applications in the United States and other jurisdictions are typically not published until 18 months after filing, or in some cases not at all. Therefore, we cannot be certain that we were the first to file for patent protection on the inventions claimed in our patents or pending patent applications. Furthermore, for U.S. applications in which all claims are entitled to a priority date before March 16, 2013, an interference proceeding can be provoked by a third-party or instituted by the USPTO to determine who was the first to invent any of the subject matter covered by the patent claims of our applications. We cannot be certain that we are the first to invent the inventions covered by pending patent applications and, if we are not, we may be subject to priority disputes. We may be required to disclaim part or all of the term of certain patents or all of the term of certain patent applications.

Previous wording

Despite the measures we take to obtain and maintain patent and other intellectual property rights with respect to our product candidates, our intellectual property rights could be challenged or invalidated. If we or one of our licensors initiate legal proceedings against a third party to enforce a patent covering one of our product candidates or our technology, the defendant could counterclaim that the patent covering our product candidate or technology, as applicable, is invalid and/or unenforceable. In patent litigation in the United States, defendant counterclaims alleging invalidity and/or unenforceability are commonplace, and there are numerous grounds upon which a third party can assert invalidity or unenforceability of a patent. Third parties may also raise similar claims before administrative bodies in the United States or abroad, even outside the context of litigation. Such mechanisms include re-examination,inter partes review, post-grant review and equivalent proceedings in foreign jurisdictions (such as opposition proceedings). Such proceedings could result in revocation or amendment to our patents in such a way that they no longer cover our product candidates or technology. The outcome following legal assertions of invalidity and unenforceability is unpredictable. With respect to the validity question, for example, we cannot be certain that there is no invalidating prior art, of which we, our patent counsel and the patent examiner were unaware during prosecution. If a defendant were to prevail on a legal assertion of invalidity and/or unenforceability, or if we are otherwise unable to adequately protect our rights, we would lose at least part, and perhaps all, of the patent protection on our product candidates or technology. Such a loss of patent protection could have a material adverse impact on our business and our ability to commercialize or license our technology and product candidates.

Current wording

Despite the measures we take to obtain and maintain patent and other intellectual property rights with respect to our product candidates, our intellectual property rights could be challenged or invalidated. If we or one of our licensors initiate legal proceedings against a third party to enforce a patent covering one of our product candidates or our technology, the defendant could counterclaim that the patent covering our product candidate or technology, as applicable, is invalid and/or unenforceable. In patent litigation in the United States, defendant counterclaims alleging invalidity and/or unenforceability are commonplace, and there are numerous grounds upon which a third party can assert invalidity or unenforceability of a patent. Third parties may also raise similar claims before administrative bodies in the United States or abroad, even outside the context of litigation. Such mechanisms include re-examination,inter partes review, post-grant review and equivalent proceedings in foreign jurisdictions (such as opposition proceedings). Such proceedings could result in revocation or amendment to our patents in such a way that they no longer cover our product candidates or technology. The outcome following legal assertions of invalidity and unenforceability is unpredictable. With respect to the validity question, for

Previous wording

Court rulings have narrowed the scope of patent protection available in certain circumstances and weakened the rights of patent owners in certain situations. In addition to increasing uncertainty regarding our ability to obtain patents in the future, this combination of events has created uncertainty with respect to the value of patents, once obtained. Depending on new legislation and decisions by the federal courts, and the USPTO, the laws and regulations governing patents could change in unpredictable ways that would weaken our ability to obtain new patents or to enforce our existing patents and patents that we might obtain in the future. For example, the U.S. Supreme Court, in the caseAmgen v. Sanofi, held that broad functional antibody claims are invalid for lack of enablement. In addition, inJuno v. Kite, the Federal Circuit held claims reciting broad antibody genus based on function invalid for lack of written description. Recently, the Federal Circuit issued precedential decisions inIn re Cellect andAllergan v. MSN that could shorten or eliminate an extended patent term awarded under patent term adjustment in certain patent family members if challenged on the basis of obviousness-type double patenting. While we do not believe that any of the patents owned or licensed by us will be found invalid based on these decisions, we cannot predict how future decisions by the courts, Congress or the USPTO may impact the value of our patents. Similarly, changes in the patent laws of other jurisdictions could adversely affect our ability to obtain and effectively enforce our patent rights, which would have a material adverse effect on our business and financial condition.

Current wording

As is the case with other biotechnology companies, our success is heavily dependent on intellectual property, particularly patents. Obtaining and enforcing patents in the biopharmaceutical industry involve both technological and legal complexity, and is therefore costly, time-consuming and inherently uncertain. In addition, the United States continues to adapt to wide-ranging patent reform legislation that became effective starting in 2012. Moreover, recent U.S. Supreme Court rulings have narrowed the scope of patent protection available in certain circumstances and weakened the rights of patent owners in certain situations. In addition to increasing uncertainty regarding our ability to obtain patents in the future, this combination of events has created uncertainty with respect to the value of patents, once obtained. Depending on new legislation and decisions by the federal courts, and the USPTO, the laws and regulations governing patents could change in unpredictable ways that would weaken our ability to obtain new patents or to enforce our existing patents and patents that we might obtain in the future. For example, the U.S. Supreme Court, in the caseAmgen v. Sanofi, held that broad functional antibody claims are invalid for lack of enablement. In addition, inJuno v. Kite, the Federal Circuit held claims reciting broad antibody genus based on function invalid for lack of written description. Recently, the Federal Circuit issued precedential decisions inIn re Cellect andAllergan v. MSN that could shorten or eliminate an extended patent term awarded under patent term adjustment in certain patent family members if challenged on the basis of obviousness-type double patenting. While we do not believe that any of the patents owned or licensed by us will be found invalid based on these decisions, we cannot predict how future decisions by the courts, Congress or the USPTO may impact the value of our patents. Similarly, changes in the patent laws of other jurisdictions could adversely affect our ability to obtain and effectively enforce our patent rights, which would have a material adverse effect on our business and financial condition.

Previous wording

It is possible that defects of form in the preparation or filing of our patents or patent applications may exist, or may arise in the future, for example with respect to proper priority claims, inventorship, claim scope, or requests for patent term adjustments. If we or our partners, collaborators, licensees or licensors fail to establish, maintain or protect such patents and other intellectual property rights, such rights may be reduced or eliminated. If our partners, collaborators, licensees or licensors are not fully cooperative or disagree with us as to the prosecution, maintenance or enforcement of any patent rights, such patent rights could be compromised. If there are material defects in the form, preparation, prosecution, or

Current wording

It is possible that defects of form in the preparation or filing of our patents or patent applications may exist, or may arise in the future, for example with respect to proper priority claims, inventorship, claim scope, or requests for patent term adjustments. If we or our partners, collaborators, licensees or licensors fail to establish, maintain or protect such patents and other intellectual property rights, such rights may be reduced or eliminated. If our partners, collaborators, licensees or licensors are not fully cooperative or disagree with us as to the prosecution, maintenance or enforcement of any patent rights, such patent rights could be compromised. If there are material defects in the form, preparation, prosecution, or enforcement of our patents or patent applications, such patents may be invalid and/or unenforceable, and such applications may never result in valid, enforceable patents. Any of these outcomes could impair our ability to prevent competition from third parties, which may have an adverse impact on our business.

Previous wording

Composition of matter patents for biological and pharmaceutical products are generally considered to be the strongest form of intellectual property protection for those types of products, as such patents provide protection without regard to any method of making or method of use. We cannot be certain, however, that the claims in our pending patent applications, including those claims covering the composition of matter of our product candidates, will be considered patentable by the USPTO or by patent offices in foreign countries, or that the claims in any of our patents that have issued or may issue will be considered valid and enforceable by courts in the United States or foreign countries. Furthermore, in some cases, we may not be able to obtain issued claims covering compositions of matter relating to our product candidates, and instead may need to rely on secondary intellectual property, including patents or patent applications with claims covering formulations, methods of use and/or methods of manufacture. Method of use patents protect a specified method of using a product, such as a method of treating a particular medical indication. This type of patent may only be enforced against a competitor through indirect infringement,i.e., inducement or contributory infringement, which is more difficult to prove than direct infringement. A competitor may be able to circumvent this type of patent by skinny labelling. Furthermore,

Current wording

Composition of matter patents for biological and pharmaceutical products are generally considered to be the strongest form of intellectual property protection for those types of products, as such patents provide protection without regard to any method of making or method of use. We cannot be certain, however, that the claims in our pending patent applications, including those claims covering the composition of matter of our product candidates, will be considered patentable by the USPTO or by patent offices in foreign countries, or that the claims in any of our patents that have issued or may issue will be considered valid and enforceable by courts in the United States or foreign countries. Furthermore, in some cases, we may not be able to obtain issued claims covering compositions of matter relating to our product candidates, and instead may need to rely on secondary intellectual property, including patents or patent applications with claims covering formulations, methods of use and/or methods of manufacture. Method of use patents protect a specified method of using a product, such as a method of treating a particular medical indication. This type of patent may only be enforced against a competitor through indirect infringement,i.e., inducement or contributory infringement, which is more difficult to prove than direct infringement. A competitor may be able to circumvent this type of patent by skinny labelling. Furthermore, this type of patent does not prevent a competitor from making and marketing a product that is identical to our product for an indication that is outside the scope of the patented method. Moreover, even if competitors do not actively promote their products for our targeted indications, physicians may prescribe these products “off-label” for those uses that are covered by our method of use patents. Although off-label prescriptions may infringe or contribute to the infringement of method of use patents, the practice is common and such infringement is difficult to prevent by enforcing patent rights or otherwise.

Previous wording

Our commercial success depends in part on our avoiding infringement of the patents and violation of other proprietary rights of third parties. There is a substantial amount of litigation involving patents and other intellectual property rights in the biotechnology and pharmaceutical industries, as well as administrative proceedings for challenging patents, including interference, reexamination, and post-grant review proceedings before the USPTO or oppositions and other comparable proceedings in foreign jurisdictions. We may be exposed to, or threatened with, future litigation or other adversarial proceedings by third parties having patent or other intellectual property rights alleging that our product candidates and/or proprietary technologies infringe their intellectual property rights. Numerous U.S. and foreign issued patents and pending patent applications, which are owned by third parties, exist in the fields in which we are developing our product candidates. As the biotechnology and pharmaceutical industries expand and more patents are issued, the risk increases that our product candidates may give rise to claims of infringement of the patent rights of others. Moreover, it is not always clear to industry participants, including us, which patents may ultimately issue because many patent filings cover various types of drugs,

Current wording

Our commercial success depends in part on our avoiding infringement of the patents and violation of other proprietary rights of third parties. There is a substantial amount of litigation involving patents and other intellectual property rights in the biotechnology and pharmaceutical industries, as well as administrative proceedings for challenging patents, including interference, reexamination, and post-grant review proceedings before the USPTO or oppositions and other comparable proceedings in foreign jurisdictions. We may be exposed to, or threatened with, future litigation or other adversarial proceedings by third parties having patent or other intellectual property rights alleging that our product candidates and/or proprietary technologies infringe their intellectual property rights. Numerous U.S. and foreign issued patents and pending patent applications, which are owned by third parties, exist in the fields in which we are developing our product candidates. As the biotechnology and pharmaceutical industries expand and more patents are issued, the risk increases that our product candidates may give rise to claims of infringement of the patent rights of others. Moreover, it is not always clear to industry participants, including us, which patents may ultimately issue because many patent filings cover various types of drugs, products or their methods of use or manufacture. Thus, because of the large number of patents issued and patent applications filed in our fields, there may be a risk that third parties may allege they have patent rights encompassing our product candidates, technologies or methods.

Previous wording

Third parties may assert that we are employing their proprietary technology without authorization. Generally, conducting preclinical and clinical trials and other development activities in the United States is not considered an act of infringement. If any of our product candidates is approved by the FDA, a third party may then seek to enforce its patent by filing a patent infringement lawsuit against us. While we do not believe that any claims that could otherwise have a materially adverse effect on the commercialization of our product candidates are valid and enforceable, we may be incorrect in this belief, or we may not be able to prove it in litigation. In this regard, patents issued in the United States by law enjoy a presumption of validity that can be rebutted only with evidence that is “clear and convincing,” a heightened standard of proof. There may be issued third-party patents of which we are currently unaware with claims to compositions, formulations, methods of manufacture or methods for treatment related to the use or manufacture of our product candidates. Patent applications can take many years to issue.

Current wording

Third parties may assert that we are employing their proprietary technology without authorization. Generally, conducting preclinical and clinical trials and other development activities in the United States is not considered an act of infringement. If any of our product candidates is approved by the FDA, a third party may then seek to enforce its patent by filing a patent infringement lawsuit against us. While we do not believe that any claims that could otherwise have a materially adverse effect on the commercialization of our product candidates are valid and enforceable, we may be incorrect in this belief, or we may not be able to prove it in litigation. In this regard, patents issued in the United States by law enjoy a presumption of validity that can be rebutted only with evidence that is “clear and convincing,” a heightened standard of proof. There may be issued third-party patents of which we are currently unaware with claims to compositions, formulations, methods