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

Since our formation in 2015 and our initial funding in 2016, our operations to date have been limited primarily to organizing and staffing our company, business planning, raising capital, researching and developing our drug discovery technology, developing our pipeline, building our intellectual property portfolio, undertaking preclinical studies and conducting Phase 1 clinical trials of our product candidates. We have never generated any revenue from drug sales. We have not obtained regulatory approvals for any of our current product candidates. Any predictions we make about our future success or viability may not be as accurate as they could be if we had a longer operating history. In addition, as a business with a limited operating history, we may encounter unforeseen expenses, difficulties, complications, delays and other known and unknown factors, such as developments relating to macroeconomic conditions. We will need to transition from a company with a research and development focus to a company capable of supporting late-stage development and commercial activities. We may not be successful in such a transition.

Since inception, we have incurred significant operating losses. To date, we have financed our operations primarily through the issuance and sale of our convertible preferred stock to outside investors, collaborators in private equity financings, upfront payments under our collaborations and sales of our common stock in our initial public offeringoffering, (IPO)or IPO, and multiple public and private offerings of common stock and our at-the market sales program. As of December 31, 2024,2025, our cash and cash equivalents and marketable securities were $850.9$1,619.4 million. We have incurred net losses in each year since our inception, and we had an accumulated deficit of $754.6$1,066.0 million as of December 31, 2024.2025. For the years ended December 31, 2024,2025, 20232024 and 2022,2023, we reported net losses of $223.9$311.4 million, $223.9 million and $147.0 million, $154.8 million, respectively. Substantially all of our operating losses have resulted from costs incurred in connection with our research and development programs and from general and administrative costs associated with our operations. We expect to continue to incur significant expenses and increasing operating losses over the next several years and for the foreseeable future. We expect our expenses to significantly increase in connection with our ongoing activities, as we:

As of December 31, 2024,2025 we had approximately $850.9$1,619.4 million of cash and cash equivalents and investments,marketable securities, which we expect will be sufficient to fund our operations into mid-2027.2029. We have based this estimate on assumptions that may prove to be wrong, and we could use our capital resources sooner than we currently expect. This estimate also assumes that we do not obtain any additional funding through collaborations or other strategic alliances. Our future capital requirements will depend on, and could increase significantly as a result of, many factors, including:

We are very early in our development efforts and our IRAK4STAT6 and STAT6IRF5 programs are in early clinical development with additional programs in preclinical development. If we are unable to advance themour programs into and through the clinic for safety or efficacy reasons or commercialize our product candidates or experience significant delays in doing so, our business will be materially harmed.

Our ability to become profitable depends upon our ability to generate revenue. To date, while we have generated collaboration revenue, we have not generated any revenue from our product candidates, and we do not expect to generate any revenue from the sale of drugs in the near future. We do not expect to generate revenue from product sales unless and until we can advance and complete the development of, obtain marketing approval for, and begin to sell, one or more of our product candidates. We are also unable to predict when, if ever, we will be able to generate revenue from such product candidates due to the numerous risks and uncertainties associated with drug development, including the uncertainty of:

the results of preclinical studies and timing of IND clearances of current and future product candidates, and/or clinical trial costs for current and future product candidates;

Because we have limited financial and management resources, weWe focus on a limited number of research programs and product candidates. We are currently focused on our immunology portfolio, consisting of our STAT6, TYK2IRF5 and IRAK4 programs, which target key signaling pathways implicated in multiple inflammatory and autoimmune diseases.diseases, as well our CDK2 program in oncology. In some instances, we may decide to discontinue our investment in programs. For example, in NovemberMay 2023,2025 we made the strategic decision to not advance KT-295 (TYK2) into further clinical development. Additionally, in June 2025, we announced theour decisionpartner Sanofi’s decisions to discontinue the development of our KT-413KT-474 (IRAKIMIDIRAK4) and in October 2024, we announced the decisionorder to discontinueprioritize the development of oura KT-333second (STAT3)generation andIRAK4 KT-253degrader, (MDM2) programs in order to focus resources to support our growing immunology pipeline.KT-485. As a result, we or our collaborators may forego or delay pursuit of opportunities with other current or future product candidates or for other indications that later prove to have greater commercial potential. Our resource allocation decisions may cause us to fail to capitalize on viable commercial drugs or profitable market opportunities. Our spending on current and future research and development programs and current or future product candidates for specific indications may not yield any commercially viable drugs. If we do not accurately evaluate the commercial potential or target market for a particular product candidate, we may relinquish valuable rights to that product candidate through future collaboration, licensing or other royalty arrangements in cases in which it would have been more advantageous for us to retain sole development and commercialization rights to such product candidate.

Positive results from our preclinical studies of our current or future product candidates, and any positive results we may obtain from our early clinical trials of our current or future product candidates, including the preclinical results that supported IND clearance for KT-579, ongoing clinical trial of KT-621 and planned clinical trials of KT-474KT-485 and KT-621,KT-579, may not necessarily be predictive of the results from required later preclinical studies and clinical trials. Similarly, even if we are able to complete our planned preclinical studies or clinical trials of our current or future product candidates according to our current development timeline, the positive results from such preclinical studies and/or clinical trials of our current or future product candidates, including KT-474, KT-621 and KT-295,KT-579, may not be replicated in subsequent preclinical studies or clinical trials. In particular, while we have conducted certain preclinical studies of KT-621 and KT-295,KT-579, we do not know whether eitherany of these product candidates will perform in our planned clinical trials as it has performed in these prior preclinical studies. For example, in preclinical studies, (i)studies KT-621 demonstrated full inhibition of IL-4/IL-13 pathway in all relevant human cell contexts with picomolar potency that wasexceeded superiorpublished todata for dupilumab, and equivalent or superior activity to dupilumab, and (ii) KT-295 demonstrated picomolar to nanomolar potencies across all relevant human cell types evaluated.dupilumab. However, there is no guarantee these preclinical results will be replicated in clinical trials. Many companies in the pharmaceutical 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. Moreover, preclinical and clinical data are often susceptible to varying interpretations and analyses, and many companies that believed their product candidates performed satisfactorily in preclinical studies and clinical trials nonetheless failed to obtain approval from the FDA or comparable foreign regulatory authority. If we fail to produce positive results in our planned preclinical studies or clinical trials of any of our current or future product candidates, the development timeline and regulatory approval and commercialization prospects for our current or future product candidates, and, correspondingly, our business and financial prospects, would be materially adversely affected.

Additionally, our planned or future clinical trials may utilize an “open-label” trial design, such as the open-label patient portion of our completed Phase 1 clinical trial of KT-474.design. An “open-label” clinical trial is one where both the patient and investigator know whether the patient is receiving the investigational product candidate or either an existing approved drug or placebo. Most typically, open-label clinical trials test only the investigational product candidate and sometimes may do so at different dose levels. Open-label clinical trials are subject to various limitations that may exaggerate any therapeutic effect as patients in open-label clinical trials are aware when they are receiving treatment. Open-label clinical trials may be subject to a “patient bias” where patients perceive their symptoms to have improved merely due to their awareness of receiving an experimental treatment. In addition, open-label clinical trials may be subject to an “investigator bias” where those assessing and reviewing the physiological outcomes of the clinical trials are aware of which patients have received treatment and may interpret the information of the treated group more favorably given this knowledge. The results from an open-label trial, including our completed Phase 1 trial of KT-474, may not be predictive of future clinical trial results with any of our product candidates for which we include an open-label clinical trial when studied in a controlled environment with a placebo or active control.

The precise incidence and prevalence for the indications being pursued by our current and future product candidates are currently unknown. Our projections of both the number of people who have these diseases, as well as the subset of people with these diseases who have the potential to benefit from treatment with our product candidates, are based on estimates. We are developing KT-474 for the treatment of a broad set of immunology-inflammation diseases, such as HS, an inflammatory skin disease, AD, and rheumatoid arthritis. We are developing KT-621 for a broad set of immunology indications, with potential indications to include AD, asthma, COPD, CRSwNP, EoE, PN and others. We are developing KT-295KT-579 for immunology indications, with such potential indications to include inflammatorylupus, bowel disease, orSjögren's, IBD, psoriasis, or PsO, psoriatic arthritis, or PsA, lupusRA and others. The total addressable market opportunity for our product candidates will ultimately depend upon, among other things, their proven safety and efficacy, the diagnosis criteria included in the final label for each, whether our product candidates are approved for sale for these indications, acceptance by the medical community and patient access, product pricing and reimbursement. The number of patients for our product candidates in the United States and elsewhere may turn out to be lower than expected, patients may not be otherwise amenable to treatment with our products, or new patients may become increasingly difficult to identify or gain access to, all of which would adversely affect our results of operations and our business.

the potential negative affect on the operations of our third-party manufacturers and the supply chain for our product candidates.candidates;

Legislative proposalsand areregulatory pendingactions that,have ifbeen enacted,taken couldthat have the potential to negatively impact U.S. companies and institutions that accept U.S. funding for projects that utilize biotechnology equipment and services produced or provided by certain biotechnology providers having relationships with foreign adversaries and which pose a threat to national security. ThisOn December 18, 2025, for example, the National Defense Authorization Act for Fiscal Year 2026 (“NDAA”) was enacted, which includes proposedSection legislation851, currentlycommonly pendingreferred to as the “BIOSECURE Act.” The BIOSECURE Act restricts U.S. government agencies from procuring certain biotechnology equipment or services from, or entering into contracts with, entities that use biotechnology equipment or services from designated “biotechnology companies of concern,” and from expending certain federal loan or grant funds for such equipment or services. While the BIOSECURE Act is primarily directed at U.S. government procurement and funding and has not yet been fully implemented through final regulations, there remains a continued policy interest in thelimiting U.S. Senatecompanies’ andrelationships Housewith ofbiotechnology Representatives.providers with relationships with foreign adversaries. The potential downstream adverse impacts on entities having only commercial relationships with any impacted biotechnology providers is unknown but may include supply chain disruptions or delays. Though we do not currently receive U.S. government funding, we arerely currentlyon evaluatingthird-party service providers and may have collaborators, investors, customers, or future commercial partners that receive U.S. government funding and could be subject to BIOSECURE-related restrictions. We regularly evaluate steps to mitigate any potential impact of any future stricterexpanded or modified legislation or regulatory or administrative actions towards foreign entities providing services to U.S. based companies. Depending on the terms of theany final legislation or administrative actions that may be enacted, these steps could result in additional costs and potential delays in development timelines resulting from related transition efforts.

If any CMO with whom we contract fails to perform its obligations, we may be forced to enter into an agreement with a different CMO, which we may not be able to do on reasonable terms, if at all. This could significantly delay our clinical trials supply as we establish alternative supply sources. In some cases, the technical skills required to manufacture our product candidates or products, if approved, may be unique or proprietary to the original CMO and we may have difficulty, or there may be contractual restrictions prohibiting us from, transferring such skills to a back-up or alternate supplier, or we may be unable to transfer such skills at all. In addition, if we are required to change CMOs for any reason, we will be required to verify that the new CMO maintains facilities and procedures that comply with quality standards and with all applicable regulations. We will also need to verify, such as through a manufacturing comparability study, that any new manufacturing process will produce our product candidate according to the specifications previously submitted to the FDA or another regulatory authority. The delays associated with the verification of a new CMO could negatively affect our ability to develop product candidates or commercialize our products in a timely manner or within budget. Furthermore, a CMO may possess technology related to the manufacture of our product candidate that such CMO owns independently. This would increase our reliance on such CMO or require us to obtain a license from such CMO in order to have another CMO manufacture our product candidates. In addition, as our current or future product candidates progress through preclinical studies and clinical trials towards potential approval and commercialization, it is expected that various aspects of the manufacturing process will be altered in an effort to optimize processes and results. Such changes may require amendments to be made to regulatory applications which may further delay the timeframestime frames under which modified manufacturing processes can be used for any of our current or future product candidates and additional bridging studies or trials may be required between our prior clinical supply used in our clinical trials and that of any new manufacturer. We may be unsuccessful in demonstrating the comparability of clinical supplies which could require the conduct of additional clinical trials. Any such delay could have a material adverse impact on our business, results of operations and prospects.

Our current or future product candidates and the activities associated with their development and commercialization, including their design, testing, manufacture, safety, efficacy, recordkeeping,record keeping, labeling, storage, approval, advertising, promotion, sale, distribution, import, and export, are subject to comprehensive regulation by the FDA and other regulatory agencies in the U.S. and by comparable authorities in other countries. Before we can commercialize any of our current and future product candidates, we must obtain marketing approval from the regulatory authorities in the relevant jurisdictions. We have not received approval to market any of our current product candidates from regulatory authorities in any jurisdiction, and it is possible that none of our current product candidates, nor any product candidates we may seek to develop in the future, will ever obtain regulatory approval. As a company, we have only limited experience in filing and supporting the applications necessary to gain regulatory approvals and expect to rely on third-party CROs and/or regulatory consultants to assist us in this process. Securing regulatory approval requires the submission of extensive preclinical and clinical data and supporting information to the various regulatory authorities for each therapeutic indication to establish the product candidate’s safety and efficacy. Securing regulatory approval also requires the submission of information about the drug manufacturing process to, and inspection of manufacturing facilities and often clinical sites by, the relevant regulatory authority. Our current or future product candidates may not be effective, may be only moderately effective or may prove to have undesirable or unintended side effects, toxicities or other characteristics that may preclude our obtaining marketing approval or prevent or limit commercial use.

With the change in presidential administrations in 2025, thereThere is substantial uncertainty as to how,whether ifand at all,how the newcurrent administration will seek to modify or revise the requirements and policies of the FDA and other regulatory agencies with jurisdiction over our product candidates. The impending uncertainty could present new challenges or potential opportunities as we navigate the clinical development and approval process for our product candidates.

If a drug is intended for the treatment of a serious or life-threatening condition and the drug demonstrates the potential to address unmet medical needs for this condition, the drug sponsor may apply for Fast Track Designation. The FDA has broad discretion whether or not to grant this designation, so even if we believe a particular current or future product candidate is eligible for this designation, we cannot assure you that the FDA would decide to grant it. In December 2025 we received Fast Track Designation for KT-621 for atopic dermatitis and we may in the future pursue Fast Track Designation for additional uses or other candidates. Even if we do receive Fast Track Designation for certain current or future product candidates, we may not experience a faster development process, review or approval compared to conventional FDA procedures. TheAdditionally, the FDA may withdraw Fast Track Designation if it believes that the designation is no longer supported by data from our clinical development program. Fast Track Designation alone does not guarantee qualification for the FDA’s priority review procedures.procedures

We or our collaborators may seek approval of KT-474, KT-621, KT-295,KT-579 or any other future product candidate, where applicable, under the FDA’s accelerated approval pathway. This pathway may not lead to a faster development or regulatory review or approval process and it does not increase the likelihood that our product candidates will receive marketing approval.

We or our collaborators may seek accelerated approval of KT-474, KT-621, KT-295,KT-579, or future product candidates. A product may be eligible for accelerated approval if it treats a serious or life-threatening condition and generally provides a meaningful advantage over available therapies. In addition, it must demonstrate an effect on a surrogate endpoint that is reasonably likely to predict clinical benefit or on a clinical endpoint that can be measured earlier than irreversible morbidity or mortality, or IMM, that is reasonably likely to predict an effect on IMM or other clinical benefit. As a condition of accelerated approval, the FDA likely would require that we perform adequate and well-controlled post-marketing clinical trials, and under FDORA the FDA is now permitted to require, as appropriate, that such trials be underway prior to approval or within a specific time period after the date of approval for a product granted accelerated approval. FDORA also gives the FDA increased authority to withdraw approval of a drug or biologic granted accelerated approval on an expedited basis if the sponsor fails to conduct such studies in a timely manner, send the necessary updates to the FDA, or if such post-approval studies fail to verify the drug’s predicted clinical benefit. Under FDORA, the FDA is empowered to take action, such as issuing fines, against companies that fail to conduct with due diligence any post-approval confirmatory study or submit timely reports to the agency on their progress. In the Consolidated Appropriations Act, Congress provided FDA with additional authorities to help prevent such delays, including that FDA may, when appropriate, require a confirmatory study or studies to be underway prior to approval. In addition, the FDA currently requires, unless otherwise informed by the Agency, pre-approval of promotional materials for products receiving accelerated approval, which could adversely impact the timing of the commercial launch of the product. Thus, even if we seek to utilize the accelerated approval pathway, we may not be able to obtain accelerated approval and, even if we do, we may not experience a faster development, regulatory review or approval process for that product. In addition, receiving accelerated approval does not assure that the product’s accelerated approval will eventually be converted to a traditional approval.

The criteria for orphan designation in the European UnionEU are similar in principle to the U.S. -– see the section of this Annual Report on Form 10-K titledentitled “Business - Government Regulation - Government Regulation of Drugs Outside of the United States” for additional information. In the European Union,EU, orphan designation entitles a party to financial incentives such as reduction of fees or fee waivers.

Inadequate funding for the FDA, the SEC and other government agencies, including from government shutdowns, or other disruptions to these agencies’ staffing and operations, could hinder their ability to hire and retain key leadership and other personnel, delay the review and approval of regulatory submissions, limit the development or implementation of regulatory programs, prevent new products and services from being developed or commercialized in a timely manner or otherwise prevent those agencies from performing normal business functions on which the operation of our business may rely, which could negatively impact our business.

Currently, federal agencies in the U.S. are operating under a continuing resolution that is set to expire on March 14, 2025. Without appropriation of additional funding to federal agencies, our business operations related to our product development activities for the U.S. market could be impacted. The ability of the FDA to review and approve new products can be affected by a variety of factors, including government budget and funding levels, the ability to hire and retain key personnel and accept the payment of user fees, and statutory, regulatory and policy changes. Average review times at the agency have fluctuated in recent years as a result.result and may continue to fluctuate as a result of these factors. In addition, government funding of the SEC and other government agencies on which our operations may rely, including those that fund research and development activities, is subject to the political process, which is inherently fluid and unpredictable. For example, the current administration has issued executive orders seeking to greatly reduce the size of the federal workforce, including through layoffs and severance packages offered to employees of federal agencies within the executive branch and independent agencies, including the FDA. Any such reduction in personnel may result in longer review times by the FDA and other agencies.

Disruptions at the FDA and other agencies may also slow the time necessary for new product candidates to be reviewed and/or approved by necessary government agencies, which would adversely affect our business. If a prolonged government shutdownshut occurs,down occurs again or if the FDA, NIH, SEC or the USPTO experiences significant decreases in funding or personnel, it could significantly impact the ability of the FDA to issues licenses needed for conduct of our clinical trials, the NIH to conduct research or provide grants, and the abilities of the FDA and the USPTO to timely review and process our regulatory submissions, which could have a material adverse effect on our business. Further, future government shutdowns could impact our ability to access the public markets and obtain necessary capital in order to properly capitalize and continue our operations.

We may in the future choose to conduct one or more clinical trials outside the U.S., including in Europe and other geographies. The acceptance of study data from clinical trials conducted outside the U.S. or another jurisdiction by the FDA or comparable foreign regulatory authority may be subject to certain conditions or may not be accepted at all. In cases where data from foreign clinical trials are intended to serve as the basis for marketing approval in the U.S., the FDA will generally not approve the application on the basis of foreign data alone unless (i) the data are applicable to the U.S. population and U.S. medical practice, (ii) the trials were performed by clinical investigators of recognized competence and (iii) the data may be considered valid without the need for an on-site inspection by the FDA or, if the FDA considers such an inspection to be necessary, the FDA is able to validate the data through an on-site inspection or other appropriate means. Additionally, the FDA’s clinical trial requirements, including sufficient size of patient populations and statistical powering, must be met. Many foreign regulatory authorities have similar approval requirements. In addition, such foreign trials would be subject to the applicable local laws of the foreign jurisdictions where the trials are conducted. There can be no assurance that the FDA or any comparable foreign regulatory authority will accept data from trials conducted outside of the U.S. or the applicable jurisdiction.jurisdiction and FDA has discussed proposals to increase user fees for marketing applications containing certain foreign clinical data. If the FDA or any comparable foreign regulatory authority does not accept such data, it would result in the need for additional trials, which could be costly and time-consuming, and which may result in current or future product candidates that we may develop not receiving approval for commercialization in the applicable jurisdiction.

The regulations that govern marketing approvals, pricing, coverage and reimbursement for new drug products vary widely from country to country. Current and future legislation may significantly change the approval requirements in ways that could involve additional costs and cause delays in obtaining approvals. Some countries require approval of the sale price of a drug before it can be marketed. In many countries, the pricing review period begins after marketing or product licensing approval is granted. In some foreign markets, prescription pharmaceutical pricing remains subject to continuing governmental control even after initial approval is granted. As a result, we might obtain marketing approval for a product in a particular country, but then be subject to price regulations that delay our commercial launch of the product, possibly for lengthy time periods, and negatively impact the revenues we are able to generate from the sale of the product in that country. Adverse pricing limitations may hinder our ability to recoup our investment in one or more product candidates, even if our product candidates obtain marketing approval. See the section of this Annual Report on Form 10-K entitled, “Business –- Government Regulation –- Other Healthcare Laws” and the section of this reportAnnual Report entitled, “Business –- Government Regulation –- Current and Future Healthcare Reform Legislation” for more information.

In the United States and some foreign jurisdictions, there have been a number of legislative and regulatory changes and proposed changes regarding the healthcare system that could prevent or delay marketing approval of our product candidates, restrict or regulate post-approval activities and affect our ability to profitably sell any product candidates for which we obtain marketing approval. The pharmaceutical industry has been a particular focus of these efforts and has been significantly affected by legislative initiatives. Current laws, as well as other healthcare reform measures that may be adopted in the future, may result in more rigorous coverage criteria and in additional downward pressure on the price that we receive for any FDA approved product. If reimbursement of our products is unavailable or limited in scope, our business could be materially harmed. See the section of this reportAnnual Report on Form 10-K entitled, “Business –- Government Regulation –- Current & Future Healthcare Reform Legislation” for more information.

Healthcare providers, physicians and third-party payors will play a primary role in the recommendation and prescription of any current or future product candidates for which we obtain marketing approval. Our business operations and any current or future arrangements with third-party payors and customers may expose us to broadly applicable federal and state laws relating to fraud and abuse, as well as other healthcare laws and regulations. Pharmaceutical companies are subject to additional healthcare regulation and enforcement by the federal government and by authorities in the states and foreign jurisdictions in which they conduct their business that may constrain the financial arrangements and relationships through which we research, as well as sell, market and distribute any products for which we obtain marketing authorization. Such laws include, without limitation, state and federal anti-kickback, fraud and abuse, false claims, and transparency laws and regulations related to drug pricing and payments and other transfers of value made to physicians and other healthcare providers. If our operations are found to be in violation of any of such laws or any other governmental regulations that apply, we may be subject to penalties, including, without limitation, administrative, civil and criminal penalties, damages, fines, disgorgement, the curtailment or restructuring of operations, integrity oversight and reporting obligations, exclusion from participation in federal and state healthcare programs and responsible individuals may be subject to imprisonment. These laws may impact, among other things, the business or financial arrangements and relationships through which we market, sell and distribute any current or future product candidates for which we obtain marketing approval. See the section of this Annual Report on Form 10-K titledentitled “Business - Government Regulation - Other Regulatory Matters - Other Healthcare Laws” for additional information.

Companies developing small molecule protein degraders therapies for patients, include, but are not limited to, Arvinas, Inc., C4 Therapeutics, Inc., Nurix Therapeutics, Inc., and Foghorn Therapeutics, Inc. Further, several large pharmaceutical companies have disclosed preclinical investments in this field. In particular, several pharmaceutical companies have announced partnerships around programs targeting STAT6, including Sanofi, Johnson & Johnson and Gilead Sciences, Inc.Gilead. Our competitors will also include companies that are or will be developing other targeted protein degradation methods as well as small molecule, antibody, or gene therapies for the same indications that we are targeting. In addition to the competitors we face in developing small molecule protein degraders, we will also face competition in the indications we expect to pursue with our IRAK4, STAT6STAT6, IRF5, and TYK2CDK2 programs. Many of these indications already have approved standards of care which may include more traditional therapeutic modalities. In order to compete effectively with these existing therapies, we will need to demonstrate that our protein degrader therapies are favorable to existing therapeutics.

Although we designed the Phase 1 and 2 trials of KT-474KT-621 and KT-621Phase 1 trial of KT-579, and intend to design other clinical trials for our current or future product candidates, or be involved in the design when other parties sponsor the trials, we anticipate that third parties will conduct all of our clinical trials. As a result, many important aspects of our clinical development, including their conduct and timing will be outside of our direct control. Our reliance on third parties to conduct clinical trials will also result in less direct control over the management of data developed through clinical trials than would be the case if we were relying entirely upon our own staff. Communicating with outside parties can also be challenging, potentially leading to mistakes as well as difficulties in coordinating activities. Outside parties may:

Regional or single-source dependencies may in some cases accentuate these risks. For example, the pharmaceutical industry generally and in some instances we or our collaborators or other third parties on which we rely on depend on China-based suppliers or services providers for certain raw materials, products and services and other activities. Our ability or the ability of our collaborators or such other third parties to continue to engage these China-based suppliers or service providers for certain preclinical research programs and clinical development programs could be restricted due to developments between the United States and China, including as a resultsresult of the escalation of tariffs or other trade restrictions or if the previously proposed federal legislation known as the BIOSECURE Act or a similar law were to be enacted.restrictions.

Recently,BIOSECURE-related thererestrictions, hasand beenany legislationfuture proposedlegislative, that,regulatory, ifor enacted,administrative actions expanding or modifying these restrictions, could negatively impact U.S. companies and institutions that accept U.S. funding for projects that utilize biotechnology equipment andor services produced or provided by certain biotechnology providers having relationships with foreign adversaries and which pose a threat to national security.adversaries. The potential downstream adverse impacts on entities having only commercial relationships with any impacted biotechnology providers is unknown but may include supply chain disruptions or delays. Though we do not currently receive U.S. government funding, BIOSECURE-related restrictions could indirectly affect our collaborators, customers, investors, or suppliers that receive U.S. government funding, and we are currently evaluating steps to mitigate any potential impact of any future stricterexpanded or modified legislation towardsor regulatory or administrative actions applicable to foreign entities providing services to U.S. based companies. Depending on the terms of the final legislationBIOSECURE enacted,Act, its implementing regulations, or any related future actions, these steps could result in additional costs and potential delays in development timelines resulting from related transition efforts For all of our current or future product candidates, we intend to identify and qualify additional manufacturers to provide such API, drug product and drug substance prior to submission of an NDA to the FDA and/or an MAA to the EMA. We are not certain, however, that our single-source and dual source suppliers will be able to meet our demand for their products. It may be difficult for us to assess their ability to timely meet our demand in the future based on past performance.

We have entered into a collaboration and licensing arrangement with Sanofi with respect to our IRAK4 program and Gilead with respect to our CDK2 program and we may in the future form or seek strategic alliances or acquisitions, create joint ventures, or enter into additional collaboration and licensing arrangements with third parties that we believe will complement or augment our development and commercialization efforts with respect to our current product candidates and any future product candidates that we may develop. Any of these relationships 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.

AsFor discussedexample, elsewherewe in this Annual Report on Form 10-K,granted our collaboration partner,partner Sanofi,Gilead isan conductingexclusive aoption randomizedfor Phasean 2exclusive clinicallicense trialwith evaluatingrespect KT-474to inour HSCDK2 program, and afuture secondpayments randomizedunder Phaseour 2licensing trialarrangement inwith AD.Gilead are contingent upon Gilead’s exercise of this option. In addition, Sanofi will havehas significant discretion in determining the efforts and resources that it will apply to advance those clinical trials.trials of KT-485. As a result of the factors noted above, we may not be able to realize the benefit of our existing collaboration and licensing arrangements or any future strategic partnerships or acquisitions, collaborations or license arrangements we may enter into, which could delay our timelines or otherwise adversely affect our business.

Our commercial success depends in part on our ability to obtain and maintain patent or other intellectual property protection in the U.S. and other countries for our current or future product candidates and our core technologies, including our proprietary TPD expertise, our,and our STAT6, TYK2IRAK4, IRF5, and IRAK4CDK2 programs, which are our most advanced development programs, as well as our proprietary compound library, and other know-how. We seek to protect our proprietary and intellectual property position by, among other methods, filing patent applications in the U.S. and abroad related to our proprietary technology, inventions and improvements that are important to the development and implementation of our business. We also rely on trade secrets, know-how and continuing technological innovation to develop and maintain our proprietary and intellectual property position.

Even if we acquire patent protection that we expect should enable us to establish and/or maintain a competitive advantage, third parties may challenge the validity, enforceability or scope thereof, which may result in such patents being narrowed, invalidated or held unenforceable. The issuance of a patent is not conclusive as to its inventorship, scope, patent term adjustments, validity or enforceability, and our patents may be challenged in the courts or patent offices in the U.S. and abroad. We may become involved in opposition, derivation, reexamination, inter partes review, or post-grant review proceedings challenging our patent rights or the patent rights of others from whom we may in the future obtain licenses to such rights, in the U.S. Patent and Trademark Office, or USPTO, the European Patent Office, or EPO, the Unified Patent Court, or UPC, or in other countries.countries or jurisdictions. In addition, we may be subject to third-party submissions to the USPTO, the EPO, or elsewhere, that may reduce the scope or preclude the granting of claims from our pending patent applications. Competitors may challenge our issued patents or may file patent applications before we do. Competitors may also claim that we are infringing their patents and that we therefore cannot practice our technology as claimed under our patents or patent applications. Competitors may also contest our patents by showing an administrative patent authority or judge that the invention was not patent-eligible, was not novel, was obvious, and/or lacked inventive step, and/or that the patent application failed to meet relevant requirements relating to description, basis, enablement, and/or support; in litigation, a competitor could assert that our patents are not valid or are unenforceable for a number of reasons. If a court or administrative patent authority agrees, we would lose our protection of those challenged patents.

We are highly dependent on the research and development, clinical and business development expertise of Nello Mainolfi, Ph.D., our President and Chief Executive Officer, Jared Gollob, M.D., our Chief Medical Officer, Bruce Jacobs, our Chief Financial Officer, EllenBrian Chiniara,Adams, our Chief Legal Officer andOfficer, Jeremy Chadwick, our Chief Operating Officer and Noah Goodman, our Chief Business Officer, as well as the other principal members of our management, scientific and clinical teams. Although we have entered into employment letter agreements with our executive officers, each of them may terminate their employment with us at any time. We do not maintain “key person” insurance for any of our executives or other employees. In addition, we rely on consultants and advisors, including scientific and clinical advisors, to assist us in formulating our research and development and commercialization strategy. Our consultants and advisors may be employed by employers other than us and may have commitments under consulting or advisory contracts with other entities that may limit their availability to us. If we are unable to continue to attract and retain high quality personnel, our ability to pursue our growth strategy will be limited.

We rely on information technology systems that we or our third-party providers operate to process, transmit and store electronic information in our day-to-day operations. In connection with our product discovery efforts, we may collect and use a variety of personal data, such as names, mailing addresses, email addresses, phone numbers and clinical trial information. A successful cyberattack, security incident, or compromise could result in the theft or destruction of intellectual property, data or other misappropriation of assets, or otherwise compromise our confidential or proprietary information and disrupt our operations. Cyberattacks are increasing in their frequency, sophistication and intensity, and have become increasingly difficult to detect. Cyberattacks could include wrongful conduct by hostile foreign governments, employee error or malfeasance, industrial espionage, wire fraud and other forms of cyber fraud, the deployment of harmful malware, denial-of-service, social engineering fraud(including successful phishing attacks) or other means to threaten data security, confidentiality, integrity and availability. AThese successfulattacks cyberattackand couldactivity causeare seriousalso negativebeing consequencesfacilitated foror us,enhanced including,by withoutevolving limitation, the disruption of operations, the misappropriation of confidential business information,technologies, including financialartificial information, trade secrets, financial loss and the disclosure of corporate strategic plans. Although we devote resources to protect our information systems, we realize that cyberattacks are a threat, and there can be no assurance that our efforts will prevent information security breaches that would result in business, legal, financial or reputational harm to us, or would have a material adverse effect on our results of operations and financial condition. Any failure to prevent or mitigate security breaches or improper access to, use of, or disclosure of our clinical data or patients’ personal data could result in significant liability under state (e.g., state breach notification laws), federal (e.g., HIPAA, as amended by HITECH), and international law (e.g., the EU General Data Protection Regulation, or GDPR) and may cause a material adverse impact to our reputation, affect our ability to use collected data, conduct new studies and potentially disrupt our business.intelligence.

WeLike other companies in our industry, we and certain of our service providers have experienced and may in the future experience cyberattacks.cyberattacks and other attempts to disrupt or gain unauthorized access to our and our third-party vendors’ information systems. We rely on our third-party providers to implement effective security measures and identify and correct for any such failures, deficiencies or breaches. We also rely on our employees and consultants to safeguard their security credentials and follow our policies and procedures regarding use and access of computers and other devices that may contain our sensitive information. If we or our third-party providers fail to maintain or protect our information technology systems and data integrity effectively or fail to anticipate, plan for or manage significant disruptions to our information technology systems, we or our third-party providers could have difficulty preventing, detecting and controlling such cyber-attacks and any such attacks could result in losses described above, as well as disputes with physicians, patients and our partners, regulatory sanctions or penalties, increases in operating expenses, expenses or lost revenues or other adverse consequences, any of which could have a material adverse effect on our business, results of operations, financial condition, prospects and cash flows. Any failure by such third parties to prevent or mitigate security incidents, data breaches or improper access to or disclosure of such information could have similarly adverse consequences for us. If we are unable to prevent or mitigate the impact of such security or data privacy breaches, we could be exposed to litigation and governmental investigations, which could lead to a potential disruption to our business. Our contracts may not contain limitations of liability, and even where they do, there can be no assurance that limitations of liability in our contracts are sufficient to protect us from liabilities, damages, or claims related to our privacy and data security obligations. Further, although we maintain cyber liability insurance, this insurance may not provide adequate coverage against potential liabilities related to any experienced security incident or data breach.

For example, with respect to the collection and processing of personal data relating to the European Union (“EU”),EU, European Economic Area (“EEA”) and United Kingdom (“UK”), we are subject to the EU General Data Protection Regulation (EU GDPR), the UK General Data Protection Regulation (UK GDPR), as well as applicable data protection laws in effect in the Member States of the EEA and in the UK (including the UK Data Protection Act 2018) which govern the processing of personal data in connection with (a) the offering of goods or services to/the monitoring of the behavior of individuals in the UK and EEA; or (b) the activities of our establishments in the UK and any EEA Member State. The UK’s data protection regime is independent from but aligned to the EU’s data protection regime. In this Form 10-K, “GDPR” refers to both the EU GDPR and the UK GDPR, unless specified otherwise. The GDPR is wide-ranging in scope and imposes numerous requirements on companies that process personal data, including imposing special requirements in respect of the processing of health and other sensitive data, requiring that consent of individuals to whom the personal data relates is obtained in certain circumstances, requiring additional disclosures to individuals regarding data processing activities, requiring that safeguards are implemented to protect the security and confidentiality of personal data, limiting retention periods for personal data, creating mandatory data breach notification requirements in certain circumstances, and requiring that certain measures (including contractual requirements) are put in place when engaging third-party service providers. The GDPR also imposes strict rules on the transfer of personal data to countries outside of the UK and EEA that do not ensure an adequate level of protection, including the United States in certain circumstances, unless derogation exists or a valid GDPR transfer mechanism (for example, the European Commission approved Standard Contractual Clauses (SCCs) and the UK International Data Transfer Agreement or Addendum (UK IDTA)) have been put in place, and transfer impact assessments conducted. Any inability to transfer personal data from the UK or EEA to the United States in compliance with data protection laws may impede our operations and may adversely affect our business and financial position. Following the UK’s exit from the EU, or Brexit, there will be increasing scope for divergence in application, interpretation and enforcement of the data protection laws between these territories. For example, the UK has introduced the Data Reform Bill into the UK legislative process with the intention for this bill to reform the UK’s data protection regime following Brexit. If passed, the final version of the Data Reform Bill may have the effect of further altering the similarities between the UK and EEA data protection regimes and threaten the UK adequacy decision from the EU Commission allowing the free flow of personal data from the UK to the EEA, which may lead to additional compliance costs and could increase our overall risk. This lack of clarity on future UK laws and regulations and their interaction with those of the EEA could add legal risk, uncertainty, complexity, and cost to our handling of European personal data and our privacy and security compliance programs, and could require us to implement different compliance measures for the UK and EEA. Failure to comply with the requirements of the GDPR and the related national data protection laws of the EEA Member States and the UK may result in fines up to €20 million (17.5 million for the UK GDPR) or 4% of a company’s global annual revenues for the preceding financial year, whichever is higher. The GDPR also confers a private right of action on data subjects and consumer associations to lodge complaints with supervisory authorities, seek judicial remedies, and obtain compensation for damages resulting from violations of the GDPR. Complying with these European data protection laws may impose significant costs or otherwise require us to divert resources or implement changes to our business processes, and any actual or perceived non-compliance could result in significant penalties, claims and reputational damage.

In the United States, several layers of federal and state data protection laws and regulations may apply to our business, including HIPAA, the Federal Trade Commission (“FTC”) Act and state consumer privacy and health data privacy laws. For example, the California Consumer Privacy Act (“CCPA”) is a comprehensive privacy law that creates individual privacy rights and increased privacy and security obligations on businesses handling the personal data of California residents. The CCPA requires covered businesses to provide certain disclosures to consumers about data collection, use and sharing practices, to allow California residents to opt out of certain sales and disclosures of personal information, and to opt out of certain uses of sensitive personal information, including health information. The law also created a regulatory agency in California, and that agency’s finalized and proposed regulations are continuing to change the standard of privacy protection we may be required to meet. Numerous other states have passed similar consumer privacy laws that are or will be implemented and enforced by various state regulators. Like the CCPA, these laws grant consumers rights in relation to their personal information and impose new obligations on regulated businesses, including, in some instances, broader data security requirements. These laws may add additional complexity, variation in requirements, restrictions and potential legal risk, require additional investment of resources in compliance programs, impact strategies and the availability of previously useful data and could result in increased compliance costs and/or changes in business practices and policies. The existence of comprehensive privacy laws in more than a dozen states will make our compliance obligations more complex and costly and may increase the likelihood that we may be subject to enforcement actions or otherwise incur liability for noncompliance.

In addition, federal and state legislators and regulators are imposing new and heightened protections for health and other sensitive information that could impact our business. For example, the Federal Trade Commission (“FTC”) has imposed stringent requirements on the collection and disclosure of sensitive categories of personal information, including health information, and has expanded the application of its Health Breach Notification Rule. ThroughFurther, through executive and legislative action, the federal government has also taken steps to restrictrestricts data transactions involving certain sensitive data categories – including health data, genetic data, and biospecimens – with persons affiliated with China, Russia, and other countries of concern.concern, Washington’sincluding Mythrough Healththe MyDepartment of Justice’s January 8, 2025, rule on “Preventing Access to U.S. Sensitive Personal Data Act,and whichGovernment-Related wentData intoby effectCountries of Concern or Covered Persons”. The rule also prohibits covered businesses from engaging in March 2024, requires regulated entities to obtain consent to collect health information, grants consumers certain rights,investment includingagreements, toemployment requestagreements deletion,or vendor agreements involving such data and provides for robust enforcement mechanisms, including enforcement by the state attorney-general and by litigants through a private rightcountries of actionconcern, forabsent consumerspecified claims.cybersecurity Thesecontrols. currentActual andor futurealleged dataviolations privacyof these laws and regulations may requirebe uspunishable toby modify our data collection or processing practices and policies, incur substantial costs and expenses in an effort to comply and increase our potential exposure to regulatory enforcement, reputational damage,criminal and/or litigation.civil sanctions, result in exclusion from participation in federal and state programs or restrict our ability to use certain vendors, sites, investigators, or service providers in global clinical trials.

We are a clinical-stage biopharmaceutical company dedicated to reinventing the treatment of human disease through the development of innovative, highly differentiated oral medicines that address significant health problems and that meaningfully improve patients’ lives. We are committed to advancing novel technologies to address targets that have known disease-causing biology, but which have not been drugged, or have been inadequately drugged, often based on limitations of existing technologies. Our approach is intended to discover and develop a new generation of medicines in a disease-agnostic manner.

We are a leader in targeted protein degradation,degradation or TPD,(TPD), a next-generation small molecule therapeutic modality that engages the body’s natural cellular recycling system to selectively eliminate disease-causing proteins. Our objective is to develop molecules that are both potent and highly selective, creating the unique potential for our medicines to uniquely address diseases that are poorly served by current treatment options. To date, we have progressed fivemultiple programs into clinical development and expect to advance at least one new molecular entity into clinical testing annually. We intend to leverage our drug development expertise to become a fully integrated biopharmaceutical company with an industry-leading pipeline of novel medicines.

Our current focusdiscovery isand development efforts are primarily directed at high-value targets in immunology. We believe there are more than 160 million patients in the United States, Europe and Japan that are diagnosed with some of the most prevalent immune-inflammatory diseases that our programs arehave designedthe potential to address, nearly half of whom remain untreated. Of those treated, most patients are treated with therapies that do not treat the underlying diseases but mostly their symptoms. As a result, only a small percentage of patients, which we believe to be approximately 3% of the diagnosed population with moderate to severe inflammatory diseases, are currently treated with systemic advanced therapies, mostly injectable biologics. While generally efficacious, biologics have drawbacks. Biologics tend to be more expensive to manufacture, and the cost isburden typicallyultimately passedfalls on to patients and payors. Patient access to therapy can also be a challenge, as biologics arecan be more complex to prescribe and reimburse than small molecule medicines. Additionally, biologics are administered as injections,injections - which may result in injection site reactions or pain - a less preferred route of administration for patients as compared to oral medications, which offer greater flexibility for patients. We believe we have the potential to deliver a compelling value proposition to a significant underserved patient population: small molecule medicines with biologics-like activity through the convenience of a daily, oral administration of a pill.

Our publicly disclosed immunology programs target STAT6, TYK2IRF5 and IRAK4, each of which addresses targets within validated pathways, providing the opportunity to treat a broad range of diseases. We are developing KT-621 as part of our STAT6 program, whichand isrecently currentlyinitiated beingthe evaluatedBROADEN2 Phase 2b clinical trial in adult and adolescent patients with moderate to severe Atopic Dermatitis (AD) and the BREADTH Phase 2b clinical trial in adult patients with moderate to severe asthma. We are also developing KT-579 as part of our oral IRF5 degrader program, and we recently initiated a Phase 1 clinical trial in healthy volunteers. Our lead molecule in our TYK2 program is KT-295, which we anticipate will enter the clinic in the second quarter of 2025. We are collaborating with Sanofi S.A.,S.A. or Sanofi,(“Sanofi”) on the development of drugour candidatesIRAK4 targetingdegrader, IRAK4,KT-485/SAR447971, including KT-474/SAR444656, outside of oncology and immuno-oncology fields.which Sanofi hasplans initiatedto twoadvance Phase 2binto clinical trials of KT-474testing in patients2026. In June 2025, we announced a strategic collaboration with hidradenitisGilead suppurativaSciences, Inc. (HS“Gilead”) andto indevelop patientsnovel withoral atopicmolecular dermatitisglue (AD).degraders for CDK2. Our additional early undisclosed pipeline focusesprograms focus on addressing high impact targets that have been elusive to conventional modalities and that drive the pathogenesis of multiple serious diseases with significant unmet medical needs.

In addition to our immunology focus, we also have research initiatives in other therapeutic areas. Additionally, we believe many of our key discovery and development capabilities have broad applicability, creating an opportunity for us to develop impactful therapeuticstherapies leveraging small-molecule modalities in addition to TPD.

As of December 31, 2024,2025, we had cash, cash equivalents and marketable securities of $850.9$1,619.4 million. We believe the existing cash, cash equivalents and marketable securities on hand will be sufficient to fund our operations into mid 2027, which will enable us to execute on multiple data readouts across our programs.2029. We have based this estimate on assumptions that may prove to be wrong, and we could exhaust our available capital resources sooner than we expect. See “Liquidity and capital resources” below.

To date, we have not generated any revenue from product sales and do not expect to generate any revenue from the sale of products in the foreseeable future. Our only revenues have been derived from research collaboration arrangements with Vertex Pharmaceuticals Incorporated, or Vertex,Vertex,, Sanofi and Sanofi.Gilead. We expect that our revenue for the next several years will be derived primarily from our current collaboration agreements and any additional collaborations that we may enter into in the future. To date, we have not received any royalties under any of the collaboration agreements.

On July 7, 2020, we entered into a collaboration agreement, or the Sanofi Agreement, with Sanofi to co-develop drug candidates directed to two biological targets. Under the Sanofi Agreement, we granted to Sanofi a worldwide exclusive license to develop, manufacture and commercialize certain lead compounds generated during the collaboration directed against IRAK4 and one additional undisclosed target in an undisclosed field of use. Such license is exercisable on a collaboration target-by-collaboration target basis only after a specified milestone. For compounds directed against IRAK4, the field of use includes diagnosis, treatment, cure, mitigation or prevention of any diseases, disorders or conditions, excluding oncology and immuno-oncology. We are responsible for discovery and preclinical research and conducting a phase 1 clinical trial for at least one degrader directed against IRAK4 plus up to three backup degraders. With respect to both targets, Sanofi is responsible for development, manufacturing, and commercialization of product candidates after a specified development milestone occurs with respect to each collaboration candidate.immune-oncology.

WeIn haveaddition, pursuant to the Sanofi Agreement, Sanofi will grant to us an exclusive option, or Opt-In Right, exercisableexercisable, at our sole discretion, on a collaboration-target-by-collaboration-targetcollaboration target-by-collaboration target basis that will include the right to (i) to fund 50% of the United States development costs for collaboration products directed against such target in the applicable field of use and (ii) share equally in the net profits and net losses of commercializing collaboration products directed against such target in the applicable field of use in the United States. In addition, if we exercise theour Opt-In Right, Sanofi will grant to us an exclusive option, applicable to each collaboration target, which upon exercise will allow us to conduct certain co-promotion activities in the field in the United States.

In September 2023, the Company and Sanofiwe mutually agreed to cease activities related to Collaborationthe Targetundisclosed 2.target and we are no longer eligible for the milestone and royalty payments associated with the second target.

We recognize revenue under each of our collaboration agreements based on our pattern of performance related to the respective identified performance obligation,obligations, which is the period over which we will perform research services under each of the respective agreements.

Research and development expenses were $240.2 million for the year ended December 31, 2024, compared to $189.1 million for the year ended December 31, 2023. The increase of $51.2 million was primarily due to an increase of $58.4$30.1 million in costs related to our STAT6, TYK2clinical and MDM2preclinical programs, asand well as an increaseincreases of $21.1$10.9 million and $10.1 million respectively in personnel,personnel and stock-based compensation costs, and occupancy and overhead costs due to increases in employee headcount in our research and development functions. These increases were partially offset by a $10.9 million reduction in activities related to our IRAK4 and STAT3 programs and a $17.4 million reduction in our other research and development costs due to stage progression and breakout of STAT6 and TYK2 programs.headcount.

General and administrative expenses were $63.5 million for the year ended December 31, 2024, compared to $55.0 million for the year ended December 31, 2023. The $8.5 million increase was primarily due to a $7.0 million increase in personnel, stock-based compensation and occupancy costs due to increases in employee headcount in the general and administrative functions,headcount, and a $1.5 million increase in legal and professional services expenses to support our operations as a public company.

In October 2021, we entered into a sales agreement, or Cowen Sales Agreement, with Cowen, pursuant to which we were able to offer and sell shares of our common stock having aggregate gross proceeds of up to $250.0 million from time to time in “at-the-market” offerings through Cowen, as our sales agent. We agreed to pay Cowen a commission of up to 3.0% of the gross proceeds of any shares sold by Cowen under the Sales Agreement. AsThrough ofOctober December 31,30, 2024, we have sold 1,519,453 shares of common stock under the Sales Agreement resulting in gross proceeds of approximately $50 million. On October 30, 2024, Cowen acknowledged and accepted our prior written notice to terminate the Cowen Sales Agreement, which termination was effective on October 30, 2024. As a result of such termination, we will not offer or sell any additional shares of common stock under the Cowen Sales Agreement.

We believe the existing cash, cash equivalents and marketable securities of $850.9$1,619.4 million as of December 31, 2024,2025, will be sufficient to fund our operations into mid 2027.2029. We have based this estimate on assumptions that may prove to be wrong, and we could use our capital resources sooner than we currently expect. We expect that we will require additional funding to continue the clinical development of our clinical programs, commercialize our product candidates if we receive regulatory approval, and pursue in-licenses or acquisitions of other product candidates. If we receive regulatory approval for any of our product candidates, we expect to incur significant commercialization expenses related to product manufacturing, sales, marketing and distribution, depending on where we choose to commercialize our product candidates.

We measure equity-based awards granted to employees, directors, and nonemployees based on their fair value on the date of the grant and recognize compensation expense for those awards over the requisite service period, which is generally the vesting period of the respective award. The equity-based payments include grants of stock options and grants of common stock, including commonrestricted stock subject to vesting.units. The measurement date for equity awards is the date of grant, and equity-based compensation costs are recognized as expense over the requisite service period, which is the vesting period, on a straight-line basis. The fair value of each stock option grant is estimated on the date of grant using the Black-Scholes option-pricing model, which requires inputs based on certain subjective assumptions, including the expected stock price volatility, the expected term of the option, the risk-free interest rate for a period that approximates the expected term of the option, and our expected dividend yield. Expected volatility is calculated based on reported volatility data for a representative group of publicly traded companies for which historical information is available. We select companies with comparable characteristics to us with historical share price information that approximates the expected term of the equity-based awards. We compute the historical volatility data using the daily closing prices for the selected companies’ shares during the equivalent period that approximates the calculated expected term of our stock options. We will continue to apply this method until a sufficient amount of historical information regarding the volatility of our stock price becomes available. The risk-free interest rate is based on the U.S. Treasury yield curve in effect at the time of grant commensurate with the expected term assumption. We use the simplified method, under which the expected term is presumed to be the midpoint between the vesting date and the end of the contractual term. We utilize this method due to lack of historical exercise data. The expected dividend yield is assumed to be zero as we have no current plans to pay any dividends on common stock.

Since inception, we have incurred significant operating losses. To date, we have financed our operations primarily through the issuance and sale of our convertible preferred stock to outside investors, collaborators in private equity financings, upfront payments under our collaborations and sales of our common stock in our initial public offering, or IPO, and multiple public and private offerings of common stock and our at-the market sales program. As of MarchJune 31,30, 2026, our cash and cash equivalents and marketable securities were $1,546$1,505 million. We have incurred net losses in each year since our inception, and we had an accumulated deficit of $1,135$1,196.4 million as of MarchJune 31,30, 2026. For the years ended December 31, 2025, 2024 and 2023, we reported net losses of $311.4 million, $223.9 million and $147.0 million, respectively. We reported net losses of $69.2$61.2 million and $65.6$130.4 million for the three and six months ended MarchJune 31,30, 2026 respectively, and $76.6 million and $142.2 million for the three and six months ended June 30, 2025, respectively. Substantially all of our operating losses have resulted from costs incurred in connection with our research and development programs and from general and administrative costs associated with our operations. We expect to continue to incur significant expenses and increasing operating losses over the next several years and for the foreseeable future. We expect our expenses to significantly increase in connection with our ongoing activities, as we:

As of MarchJune 31,30, 2026 we had approximately $1,546$1,505 million of cash and cash equivalents and marketable securities, which we expect will be sufficient to fund our operations into 2029. We have based this estimate on assumptions that may prove to be wrong, and we could use our capital resources sooner than we currently expect. This estimate also assumes that we do not obtain any additional funding through collaborations or other strategic alliances. Our future capital requirements will depend on, and could increase significantly as a result of, many factors, including:

We are very early in our development efforts and our STAT6 and IRF5 programs are in early clinical development with additional programs in preclinical development or early clinical development. If we or our collaborators are unable to advance our programs into and through the clinic for safety or efficacy reasons or commercialize our product candidates or experience significant delays in doing so, our business will be materially harmed.

There may be delays in trial initiation, including due to clinical holds or site activation delays, and we may not be able to locate and enroll a sufficient number of eligible patients to participate in these trials as required by the FDA or similar regulatory authorities outside the U.S. Moreover, some of our competitors have ongoing clinical trials for current or future product candidates that treat the same patient populations as our current or future product candidates, and patients who would otherwise be eligible for our clinical trials or those trials conducted by our collaborators, may instead enroll in clinical trials of our competitors’ current or future product candidates.

Positive results from our preclinical studies of our current or future product candidates, and any positive results we may obtain from our early clinical trials of our current or future product candidates, including the preclinical results that supported IND clearance for KT-579, ongoing clinical trials of KT-621 andKT-621, KT-579 and planned clinical trials of KT-485, may not necessarily be predictive of the results from required later preclinical studies and clinical trials. Similarly, even if we are able to complete our planned preclinical studies or clinical trials of our current or future product candidates according to our current development timeline, the positive results from such preclinical studies and/or clinical trials of our current or future product candidates, including KT-621 and KT-579, may not be replicated in subsequent preclinical studies or clinical trials. In particular, while we have conducted certain preclinical studies of KT-621 and KT-579, we do not know whether any of these product candidates will perform in our planned clinical trials as it has performed in these prior preclinical studies. For example, in preclinical studies KT-621 demonstrated full inhibition of IL-4/IL-13 pathway in all relevant human cell contexts with picomolar potency that exceeded published data for dupilumab, and equivalent or superior activity to dupilumab. However, there is no guarantee these preclinical results will be replicated in clinical trials. Many companies in the pharmaceutical 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. Moreover, preclinical and clinical data are often susceptible to varying interpretations and analyses, and many companies that believed their product candidates performed satisfactorily in preclinical studies and clinical trials nonetheless failed to obtain approval from the FDA or comparable foreign regulatory authority. If we fail to produce positive results in our planned preclinical studies or clinical trials of any of our current or future product candidates, the development timeline and regulatory approval and commercialization prospects for our current or future product candidates, and, correspondingly, our business and financial prospects, would be materially adversely affected.

the potential negative affecteffect on the operations of our third-party manufacturers and the supply chain for our product candidates;

The process of obtaining regulatory approvals, both in the U.S. and abroad, is expensive, may take many years if additional clinical trials are required, if approval is obtained at all, and can vary substantially based upon a variety of factors, including the type, complexity and novelty of the product candidates involved. Changes in marketing approval policies during the development period, changes in or the enactment of additional statutes or regulations, changes in leadership, or changes in regulatory review for each submitted NDA or equivalent application type outside the U.S., may cause delays in the approval or rejection of an application. The FDA and comparable authorities in other countries have substantial discretion in the approval process and may refuse to accept any application or may decide that our data are insufficient for approval and require additional preclinical, clinical or other studies. The U.S. Supreme Court’s decision in July 2024 to overturn established case law giving deference to regulatory agencies’ interpretations of ambiguous statutory language has introduced uncertainty regarding the extent to which FDA’s regulations, policies and decisions may become subject to increasing legal challenges, delays or changes. Our current or future product candidates could be delayed in receiving, or fail to receive, regulatory approval for many reasons, including the following:

There is substantial uncertainty as to whetherthe extent and howmanner in which the current administration will seek to modify or revise the requirements and policies of the FDA and other regulatory agencies with jurisdiction over our product candidates. The impending uncertainty could present new challenges or potential opportunities as we navigate the clinical development and approval process for our product candidates.

We may seek Breakthrough Therapy Designation and/or Fast Track Designation for any of our current or future product candidates. These designations, even if granted by the FDA, may not lead to a faster development, regulatory review or approval process, and such designations do not increase the likelihood that any of our product candidates will receive marketing approval in the United States. Even if we receive a designation for one or more of our product candidates, we may be unable to maintain the designation if FDA believes the conditions for the designation are no longer supported.

If the FDA or a comparable foreign regulatory authority approves any of our current or future product candidates, the manufacturing processes, labeling, packaging, distribution, tracking and tracing, adverse event reporting, storage, advertising, promotion and recordkeeping for the drug will be subject to extensive and ongoing regulatory requirements. These requirements include submissions of safety and other post-marketing information and reports, registration requirements, and continued compliance with cGMPs and Good Clinical Practices, or GCPs, for any clinical trials that we conduct post-approval. For certain commercial prescription drug products, manufacturers and other parties involved in the supply chain must also meet chain of distribution requirements and build electronic, interoperable systems for product tracking and tracing and for notifying the FDA of counterfeit, diverted, stolen and intentionally adulterated products or other products that are otherwise unfit for distribution in the United States. Any regulatory approvals that we receive for our current or future product candidates may also be subject to limitations on the approved indicated uses for which the drug may be marketed or to the conditions of approval, or contain requirements for potentially costly post-marketing testing, including Phase 4 clinical trials, and surveillance to monitor the safety and efficacy of the drug. If we or a regulatory agency discover problems with any of our future approved drugs, such as adverse events of unanticipated severity or frequency, or problems with the facility where such drug products are manufactured, a regulatory agency may impose restrictions on such drug products, the manufacturer or us, including requiring withdrawal of the product from the market or suspension of manufacturing. Additionally, under FDORA, sponsors of approved drugs and biologics must provide 6 months’ notice to the FDA of any changes in marketing status, or for discontinuing or interrupting supply of certain drugs, including the withdrawal of a drug, and failure to do so could result in a letter citing such failure to comply and public posting of such letter and redacted company response which could damage the company’sour reputation. The FDA closely regulates the post-approval marketing and promotion of pharmaceutical and biological products to ensure such products are marketed only for the approved indications and in accordance with the provisions of the approved labeling. Later discovery of previously unknown problems with a drug, including adverse events of unanticipated severity or frequency, or with our third-party manufacturers or manufacturing processes, or failure to comply with regulatory requirements, may result in, among other things:

The ability of the FDA to review and approve new products can be affected by a variety of factors, including government budget and funding levels, the ability to hire and retain key personnelpersonnel, and the ability to accept the payment of user fees, and statutory, regulatory and policy changes. Average review times at the agency have fluctuated in recent years as a result and may continue to fluctuate as a result of these factors. In addition, government funding of the SEC and other government agencies on which our operations may rely, including those that fund research and development activities, is subject to the political process, which is inherently fluid and unpredictable. For example, the current administration has issued executive orders seeking to greatly reduce the size of the federal workforce, including through layoffs and severance packages offered to employees of federal agencies within the executive branch and independent agencies, including the FDA. Any such reduction in personnel may result in longer review times by the FDA and other agencies.

Disruptions at the FDA and other federal agencies, including from federal government shutdowns like the one that occurred in October 2025, and the partial government shutdown that occurred in January and February 2026, substantial leadership departures, personnel cuts, and policy changes, may also slow the time necessary for new drugs to be reviewed and/or approved, which would harm our business. These changes have been reported by some within the pharmaceutical industry as creatingresulting in instances of delays in the FDA’s responsiveness or in its ability to review IND submissions or applications, issue regulations or guidance, or implement or enforce regulatory requirements in a timely fashion or at all.

If a prolonged government shut down occurs again or if the FDA, NIH, SEC or the USPTO experiences significant decreases in funding or personnel, it could significantly impact the ability of the FDA to issuesissue licenses needed for the conduct of our clinical trials, the NIH to conduct research or provide grants, and the abilities of the FDA and the USPTO to timely review and process our regulatory submissions, which could have a material adverse effect on our business. Further, future government shutdowns could impact our ability to access the public markets and obtain necessary capital in order to properly capitalize and continue our operations.

There is substantial uncertainty as to whetherthe extent and howmanner in which the current administration will seek to modify or revise the requirements and policies of the FDA and other regulatory agencies with jurisdiction over our product candidates and any products for which we obtain approval. Additionally, the current administration could also issue or promulgate executive orders, regulations, policies or guidance that adversely affect us or create a more challenging or costly environment to pursue the development of new therapeutic candidates or delay the review or effectiveness of required regulatory or securities filings. Also, state governments may seek to address or react to changes at the federal level with changes to their regulatory frameworks in a manner that could impact our operations.

We have conducted and may in the future conduct clinical trials for current or future product candidates outside the U.S., and the FDA and comparable foreign regulatory authorities may not accept data from such trials.

We are conducting and may in the future choose to conduct one or more clinical trials outside the U.S., including in EuropeEurope, Asia and other geographies. The acceptance of study data from clinical trials conducted outside the U.S. or another jurisdiction by the FDA or comparable foreign regulatory authority may be subject to certain conditions or may not be accepted at all. In cases where data from foreign clinical trials are intended to serve as the basis for marketing approval in the U.S., the FDA will generally not approve the application on the basis of foreign data alone unless (i) the data are applicable to the U.S. population and U.S. medical practice, (ii) the trials were performed by clinical investigators of recognized competence and (iii) the data may be considered valid without the need for an on-site inspection by the FDA or, if the FDA considers such an inspection to be necessary, the FDA is able to validate the data through an on-site inspection or other appropriate means. Additionally, the FDA’s clinical trial requirements, including sufficient size of patient populations and statistical powering, must be met. Many foreign regulatory authorities have similar approval requirements. In addition, such foreign trials would be subject to the applicable local laws of the foreign jurisdictions where the trials are conducted. There can be no assurance that the FDA or any comparable foreign regulatory authority will accept data from trials conducted outside of the U.S. or the applicable jurisdiction and FDA has discussed proposals to increase user fees for marketing applications containing certain foreign clinical data. If the FDA or any comparable foreign regulatory authority does not accept such data, it would result in the need for additional trials, which could be costly and time-consuming, and which may result in the failure to receive approval for commercialization for the current or future product candidates that we may develop not receiving approval for commercialization in the applicable jurisdiction or in the delay or halt in development of such candidates.

Factors that may inhibit our or our third-party collaborators' efforts to commercialize our current or future product candidates on our own include:

our inabilityability to recruit and retain adequate numbers of effective sales and marketing personnel;

the inabilityability of sales personnel to obtain access to physicians or persuade adequate numbers of physicians to prescribe any future drugs;

As of MarchJune 31,30, 2026, we had 253273 full-time employees, and we expect to increase our number of employees and the scope of our operations. To manage our anticipated development and expansion, we must continue to implement and improve our managerial, operational and financial systems, expand our facilities and continue to recruit and train additional qualified personnel. Our management may need to divert a disproportionate amount of its attention away from its day-to-day activities and devote a substantial amount of time to managing these development activities. Due to our limited resources, we may not be able to effectively manage the expansion of our operations or recruit and train additional qualified personnel. This may result in weaknesses in our infrastructure, give rise to operational mistakes, loss of business opportunities, loss of employees and reduced productivity among remaining employees. The expansion of our operations may lead to significant costs and may divert management’s time and financial resources from other projects, such as the development of our current or future product candidates. If our management is unable to effectively manage our expected development and expansion, our expenses may increase more than expected, our ability to generate or increase our revenue could be reduced and we may not be able to implement our business strategy. Our future financial performance and our ability to commercialize our current or future product candidates, if approved, and compete effectively will depend, in part, on our ability to effectively manage the future development and expansion of our company.

For example, with respect to the collection and processing of personal data relating to the EU, European Economic Area (“EEA”) and United Kingdom (“UK”), we are subject to the EU General Data Protection Regulation (EU GDPR), the UK General Data Protection Regulation (UK GDPR), as well as applicable data protection laws in effect in the Member States of the EEA and in the UK (including the UK Data Protection Act 2018) which govern the processing of personal data in connection with (a) the offering of goods or services to/the monitoring of the behavior of individuals in the UK and EEA; or (b) the activities of our establishments in the UK and any EEA Member State. The UK’s data protection regime is independent from but aligned to the EU’s data protection regime. In this Form 10-K,10-Q, “GDPR” refers to both the EU GDPR and the UK GDPR, unless specified otherwise. The GDPR is wide-ranging in scope and imposes numerous requirements on companies that process personal data, including imposing special requirements in respect of the processing of health and other sensitive data, requiring that consent of individuals to whom the personal data relates is obtained in certain circumstances, requiring additional disclosures to individuals regarding data processing activities, requiring that safeguards are implemented to protect the security and confidentiality of personal data, limiting retention periods for personal data, creating mandatory data breach notification requirements in certain circumstances, and requiring that certain measures (including contractual requirements) are put in place when engaging third-party service providers.

As of MarchJune 31,30, 2026, the existing holdings of our executive officers, directors, principal stockholders and their affiliates represent beneficial ownership, in the aggregate, of approximately 26%20% of our outstanding common stock. As a result, these stockholders, if they act together, will be able to influence our management and affairs and the outcome of matters submitted to our stockholders for approval, including the election of directors and any merger, consolidation or sale of all or substantially all of our assets. This may prevent or discourage unsolicited acquisition proposals or offers for our common stock that you may feel are in your best interest as one of our stockholders. Some of these persons or entities may have interests different than yours. For example, because many of these stockholders purchased their shares at prices substantially below the current trading price of our stock and have held their shares for a longer period, they may be more interested in selling our Company to an acquirer than other investors or they may want us to pursue strategies that deviate from the interests of other stockholders. Additionally, from time to time, any of our non-affiliated shareholders may accumulate or acquire significant positions in our common stock and may similarly be able to influence our business or matters submitted to our stockholders for approval. The concentration of voting power among these stockholders may also have an adverse effect on the price of our common stock by delaying, deferring or preventing a change of control of us; 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.

As of MarchJune 31,30, 2026, approximately 15,815,253 shares of our common stock were reserved for issuance upon exercise of pre-funded warrants. Additionally, 10,891,45210,514,579 shares of our common stock were reserved for issuance upon exercise of outstanding stock options and vested restricted stock units. The exercise or conversion of these securities will result in a significant increase in the number of outstanding shares and substantially dilute the ownership interests of our existing stockholders. The shares underlying the equity awards from our equity plans are registered on a Form S-8 registration statement. As a result, upon vesting these shares can be freely exercised and sold in the public market upon issuance, subject to volume limitations applicable to affiliates. The exercise of options and the subsequent sale of the underlying common stock could cause a decline in our stock price.

On February 26, 2026, we entered into a Sales Agreement, or the Cowen Sales Agreement, with TD Securities (USA) LLC, or Cowen, pursuant to which we may offer and sell our common stock, subject to certain limitations in the sales agreement and compliance with applicable law, at any time throughout the term of the Cowen Sales Agreement. The number of shares that are sold by Cowen after delivering a placement notice will fluctuate based on the market price of the common stock during the sales period and limits we set with Cowen. Because the price per share of each share sold will fluctuate based on the market price of our common stock during the sales period, it is not possible at this stage to predict the number of shares that will be ultimately issued. Sales to, or through, Cowen by us could result in substantial dilution to the interests of other holders of our common stock. Additionally, the sale of a substantial number of shares of our common stock, or the anticipation of such sales, could make it more difficult for us to sell equity or equity-related securities in the future at a time and at a price that we might otherwise wish to effect sales. ThereAs of June 30, 2026, there have not yet been any sales made pursuant to the Cowen Sales Agreement.

Pursuant to our amended and restated bylaws, unless we consent in writing to the selection of an alternative forum, the Court of Chancery of the State of Delaware is the sole and exclusive forum for any state law claims for (1) any derivative action or proceeding brought on our behalf; (2) any action asserting a claim of or based on a breach of a fiduciary duty owed by any director, officer or other employee of ours to us or our stockholders; (3) any action asserting a claim pursuant to any provision of the DGCL, our amended and restated certificate of incorporation or our amended and restated bylaws; or (4) any action asserting a claim governed by the internal affairs doctrine, or the Delaware Forum Provision. The Delaware Forum Provision will not apply to any causes of action arising under the Securities Act or the Exchange Act. Our amended and restated bylaws further provide that unless we consent in writing to the selection of an alternative forum, the federal district courts of the United States District Court for the District of MassachusettsAmerica shall be the sole and exclusive forum for resolving any complaint asserting a cause of action arising under the Securities Act, or the Federal Forum Provision. In addition, our amended and restated bylaws provide that any person or entity purchasing or otherwise acquiring any interest in shares of our capital stock is deemed to have notice of and consented to the Delaware Forum Provision and the Federal Forum Provision; provided, however, that stockholders cannot and will not be deemed to have waived our compliance with the federal securities laws and the rules and regulations thereunder.

We recognize that the Delaware Forum Provision and the Federal Forum Provision in our amended and restated bylaws may impose additional litigation costs on stockholders in pursuing any such claims, particularly if the stockholders do not reside in or near the State of Delaware or the Commonwealth of Massachusetts, as applicable.Delaware. Additionally, the forum selection clauses in our amended and restated bylaws may limit our stockholders’ ability to bring a claim in a judicial forum that they find favorable for disputes with us or our directors, officers or employees, which may discourage the filing of lawsuits against us and our directors, officers and employees, even though an action, if successful, might benefit our stockholders. In addition, while the Delaware Supreme Court ruled, and other state courts have upheld the validity of, that federal forum selection provisions purporting to require claims under the Securities Act be brought in federal court, there is uncertainty as to whether other courts will enforce our Federal Forum Provision. If the Federal Forum Provision is found to be unenforceable, we may incur additional costs associated with resolving such matters. The Federal Forum Provision may also impose additional litigation costs on stockholders who assert that the provision is not enforceable or invalid. The Court of Chancery of the State of Delaware and the federal district courts of the United States District Court for the District of MassachusettsAmerica may also reach different judgments or results than would other courts, including courts where a stockholder considering an action may be located or would otherwise choose to bring the action, and such judgments may be more or less favorable to us than our stockholders.

Our publicly disclosed oral immunology programs target STAT6, IRF5 and IRAK4, each of which addresses targets within validated pathways, providing the opportunity to treat a broad range of diseases. We are developing KT-621 as part of our STAT6 program, which is currently being evaluated in the BROADEN2 Phase 2b clinical trial in adult and adolescent patients with moderate to severe Atopic Dermatitis (AD) and the BREADTH Phase 2b clinical trial in adult patients with moderate to severe asthma. We are also developing KT-579 as part of our oral IRF5 degrader program, which is being evaluated in a Phase 1 clinical trial in healthy volunteers. We are collaborating with Sanofi S.A. (“Sanofi”) on the development of our IRAK4 degrader, KT-485/SAR447971, which Sanofiis plansbeing toevaluated advancein intoa Phase 1 clinical testingtrial. inWe 2026.are Inalso June 2025, we announced a strategic collaborationcollaborating with Gilead Sciences, Inc. (“Gilead”) toon developthe noveldevelopment oralof molecular glue degraders for CDK2. In April 2026, Gilead exercised its option to exclusively license KT-200, a first-in-class,our oral CDK2 molecular glue degrader.degrader, GileadKT-200, which is expectedcurrently to progress the program intoin IND-enabling studies to support an IND filing in 2027.studies. Our additional early undisclosed pipeline programs focus on addressing high impact targets that have been elusive to conventional modalities and that drive the pathogenesis of multiple serious diseases with significant unmet medical needs.

Since our inception in 2015, we have devoted substantially all our efforts to organizing and staffing our company, research and development activities, business planning, raising capital, building our intellectual property portfolio and providing general and administrative support for these operations. ToThrough date,June 30, 2026, we have received gross proceeds of $2.75 billion from sales of our convertible preferred stock, the sale of common stock including our August 2020 initial public offering, or IPO, and concurrent private placement, our subsequent follow-on offerings and private placement offering, our prior sales agreement with Cowen and through our corporate collaborations.

We have incurred significant operating losses since inception. Our ability to generate product revenue sufficient to achieve profitability will depend heavily on the successful development and eventual commercialization of one or more of our current product candidates or any future product candidates. Our net losses were $311.4 million and $223.9 million for the years ended December 31, 2025 and 2024, respectively. We reported net losses of $69.2$61.2 million and $65.6$130.4 million for the three and six months ended MarchJune 31,30, 2026 respectively, and $76.6 million and $142.2 million for the three and six months ended June 30, 2025, respectively. In addition, as of MarchJune 31,30, 2026 and December 31, 2025, we had an accumulated deficit of $1,135$1,196 million and $1,066.0$1,066 million, respectively. We expect that our expense and capital requirements will increase substantially in connection with our ongoing activities, particularly if and as we:

As of MarchJune 31,30, 2026, we had cash, cash equivalents and marketable securities of $1,546$1,505 million. We believe the existing cash, cash equivalents and marketable securities on hand will be sufficient to fund our operations into 2029, beyond multiple clinical inflection points in our pipeline. We have based this estimate on assumptions that may prove to be wrong, and we could exhaust our available capital resources sooner than we expect. See “Liquidity and capital resources” below.

To date, we have not generated any revenue from product sales and do not expect to generate any revenue from the sale of products in the foreseeable future. Our only revenues have been derived from research collaboration arrangements with VertexVertex, Sanofi, and Sanofi.Gilead. We expect that our revenue for the next several years will be derived primarily from our current collaboration agreements and any additional collaborations that we may enter into in the future. To date, we have not received any royalties under any of the collaboration agreements.

Pursuant to the Gilead Agreement, wethe areCompany was responsible for all discovery and preclinical research activities through the delivery of a complete data package as defined in the agreement. If, afterAfter receiving the complete data package, Gilead exercisesexercised its option to license the program,program Gileadand willnow havehas global rights to develop, manufacture and commercialize all products resulting from the collaboration.

If Gilead does not exercise the option during the option period defined in the agreement, then the Gilead Agreement will terminate. Following option exercise, the Gilead Agreement will expire on a product-by-product and country-by-country basis upon the expiration of all royalty obligations under the agreement. Gilead may terminate the agreement for convenience upon advance written notice. Each party may also terminate the agreement for material breach, insolvency, and the agreement may be terminated for certain other customary reasons, including Gilead’s right to terminate certain provisions of the agreement following a change of control of our company.

In consideration for the exclusive option and rights granted under the Gilead Agreement, we received a non-refundable upfront payment of $40.0 million. Further in April 2026, Gilead exercised its exclusive option to license KT-200,an oral CDK2 molecular glue degrader as a development candidate. As a result, we earned an option exercise milestonepayment of $45.0 million, expected to bemillion received and recognized as revenue in the second quarter of 2026. We remain eligible to receive up to an additional $665.0 million upon the achievement of certain development, regulatory and commercial milestones. We are also eligible to receive tiered royalties on net sales by Gilead ranging from high single-digit to mid-teen percentages, subject to customary reductions in certain circumstances.

In consideration for the exclusive licenses granted to Sanofi under the Sanofi Agreement, Sanofi paid to us an upfront payment of $150.0 million. In addition to the upfront payment, under the agreement we were eligible to receive certain development milestone payments of up to $1.48 billion, and commercial milestone payments of up to $700.0 million, in the aggregate. We will further be eligible to receive tiered royalties on net sales ranging from the high single digits to high teens, subject to low-single digits upward adjustments in certain circumstances. As of MarchJune 31,30, 2026, we have achieved $75.0$95.0 million of milestones under the Sanofi Agreement related to certain IRAK4 clinical and preclinical milestones.

Additionally with respect to Sanofi, on December 2, 2022, Sanofi provided the Companyus with written notice of its intention to advance the collaboration target 1 candidate, KT-474, into Phase 2 clinical trials for which the Companywe received milestone payments as further set forth in the Amended Sanofi Agreement. Phase 2 clinical trials of KT-474 are initially investigating its potential in HS and AD with the clinical trial for both indications having been initiated and commenced dosing in 2023.

In June 2025, Sanofi communicated its decision to exercise its full participation election under the terms of the companies’ collaboration agreement, and to advance KT-485/SAR447971, into clinical testing. As a result, Sanofi stopped development of KT-474. In connectionJune with2026, Sanofi informed us that the IRAK4first program,participant wewas remain eligible to receive up to $975 milliondosed in developmentthe andfirst-in-human commercialPhase milestones1 uponclinical trial evaluating KT-485/SAR447971, resulting in the achievement of certaina developmental$20 ormillion regulatory events and upon the achievement of certain net sales thresholds.milestone.

In September 2023, we mutually agreed to cease activities related to the undisclosed second target and we are no longer eligible for the milestone and royalty payments associated with the second target.

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

The following table summarizes our results of operations for the three months ended MarchJune 31,30, 2026 and 2025:

Collaboration revenues were $34.4$65.0 million and $22.1$11.5 million for the three months ended MarchJune 31,30, 2026 and 2025, respectively. All of the revenue recognized for the three months ended MarchJune 31,30, 2026 is attributable to payments achieved under our collaboration agreementagreements with Gilead,Gilead and allSanofi. All of the revenue recognized for the three months ended MarchJune 31,30, 2025 is attributable to our collaboration agreement with Sanofi.

Research and development expenses were $98.2$119.5 million for the three months ended MarchJune 31,30, 2026, compared to $80.3$78.4 million for the three months ended MarchJune 31,30, 2025. The increase of $17.9$41.1 million was primarily due to a $6.7$23.5 million increase in costs related to our STAT6 program, a $8.9 million increase in personnel, equity-based compensation, occupancy, and other internal costs due to increased investment in employee talent and facilities in the research and development functionsfunctions, and a $12.6$8.7 million increase in costs related to our STAT6 program. These increases were partially offset by a $1.4 million reduction in activities related to our non-STAT6 programs.

General and administrative expenses were $20.4$21.1 million for the three months ended MarchJune 31,30, 2026, compared to $16.3$17.6 million for the three months ended MarchJune 31,30, 2025. This increase of $4.1$3.5 million was primarily due to an increase in legal and professional service fees, personnel, facility, occupancy, and other expenses to support our growth. Equity-based compensation expenses included in general and administrative expenses were $7.4$8.6 million and $6.7$7.4 million for the three months ended MarchJune 31,30, 2026 and 2025, respectively.

Other income, net was $14.9$14.4 million for the three months ended MarchJune 31,30, 2026, compared to $8.8$7.9 million for the three months ended MarchJune 31,30, 2025. The $6.1$6.5 million increase was primarily due to an increase in the cash, cash equivalents, and investmentsmarketable securities balances resulting in higher interest income.

We have not yet generated any revenue from any product sales, and we have incurred significant operating losses since our inception. We have not yet commercialized any products and we do not expect to generate revenue from sales of products for several years, if at all. ToThrough date,June 30, 2026, we have received gross proceeds of $2.75 billion from sales of our convertible preferred stock, the sale of common stock including our August 2020 initial public offering, or IPO, and concurrent private placement, our follow-on offerings and private placement offering, our prior sales agreement with TD Securities (USA) LLC, or Cowen, and through our corporate collaborations. As of MarchJune 31,30, 2026, we had cash and cash equivalents and marketable securities of $1,546$1,505 million.

In October 2021, we entered into a sales agreement, or Prior Cowen Sales Agreement, with Cowen, pursuant to which we were able to offer and sell shares of our common stock having aggregate gross proceeds of up to $250.0 million from time to time in “at-the-market” offerings through Cowen, as our sales agent. We agreed to pay Cowen a commission of up to 3.0% of the gross proceeds of any shares sold by Cowen under the Prior Cowen Sales Agreement. As of MarchJune 31,30, 2026, we have sold 1,519,453 shares of common stock under the Prior Cowen Sales Agreement resulting in gross proceeds of approximately $50 million. On October 30, 2024, Cowen acknowledged and accepted our prior written notice to terminate the Prior Cowen Sales Agreement, which termination was effective on October 30, 2024. As a result of such termination, we will not offer or sell any additional shares of common stock under the Prior Cowen Sales Agreement.

On October 31, 2024, we entered into an Open Market Sale AgreementSM, or Jefferies Sales Agreement, with Jefferies LLC, or Jefferies, pursuant to which we were able to offer and sell shares of our common stock having aggregate gross proceeds of up to $300.0 million from time to time in “at-the-market” offerings through Jefferies, as our sales agent. We agreed to pay Jefferies a commission of up to 3.0% of the gross proceeds of any shares sold by Jefferies under the Sales Agreement. As of March 31, 2026, we have not sold any shares of common stock under the Jefferies Sales Agreement. On February 26, 2026, Jefferies acknowledged and accepted our prior written notice to terminate the Jefferies Sales Agreement, which termination was effective on February 26, 2026. As a result of such termination, we will not offer or sell any additional shares of common stock under the Jefferies Sales Agreement and as of its termination, we had not sold any shares of its common stock under the Jefferies Sales Agreement.

On February 26, 2026, we entered into a sales agreement, or Cowen Sales Agreement, with Cowen, pursuant to which we may offer and sell shares of our common stock having aggregate gross proceeds of up to $500.0 million from time to time in “at-the-market” offerings through Cowen, as our sales agent. We agreed to pay Cowen a commission of up to 3.0% of the gross proceeds of any shares sold by Cowen under the Cowen Sales Agreement. As of MarchJune 31,30, 2026, we have not sold any shares of common stock under the Cowen Sales Agreement.

During the threesix months ended MarchJune 31,30, 2026, cash used in operating activities was $88.8$142.9 million, primarily resulting from our net loss of $69.2$130.4 million during the period and a $34.9$46.4 million net decrease in other operating assets and liabilities primarily driven by changes in contract assets, deferred revenue, accounts payable, accrued expenses and operating lease liabilities. This was partially offset by adjustments for non-cash items of $15.3$33.9 million primarily consisting of stock-based compensation, depreciation & amortization and premiums & discounts on available- foravailable-for sale-securities.

During the threesix months ended MarchJune 31,30, 2025, cash used in operating activities was $79.2$139.0 million, primarily resulting from our net loss of $65.6$142.2 million during the period and a $27.3$26.0 million net decrease in other operating assets and liabilities primarily driven by changes in contract assets, deferred revenue, accounts payable, accrued expenses and operating lease liabilities. This was partially offset by adjustments for non-cash items of $13.8$29.1 million (primarily consisting of stock-based compensation, depreciation & amortization and premiums & discounts on available-available-for-sale for sale-securitiessecurities).

During the threesix months ended MarchJune 31,30, 2026, cash used in investing activities was $142.8$122.8 million comprised of purchases of marketable securities of $276.3$390.9 million, partially offset by maturities of marketable securities of $133.9$269.0 million and purchases of property and equipment of $0.4$0.9 million.

During the threesix months ended MarchJune 31,30, 2025, cash provided by investing activities was $48.6$108.6 million comprised of maturities of marketable securities of $132.7$251.7 million, partially offset by purchases of marketable securities of $83.7$141.9 million and purchases of property and equipment of $0.5$1.2 million.

During the threesix months ended MarchJune 31,30, 2025,2026, net cash provided by financing activities was $0.3$33.2 million, consisting of $0.6$32.6 million in proceeds from the exercise of employee stock options and $1.5 million from issuance of shares under our employee stock purchase plan, partially offset by finance lease payments of $0.3$0.9 million.

We believe the existing cash, cash equivalents and marketable securities of $1,546$1,505 million as of MarchJune 31,30, 2026, will enable us to fund our operating expenses and capital expenditure requirements into 2029. We have based this estimate on assumptions that may prove to be wrong, and we could exhaust our available capital resources sooner than we expect. We expect that we will require additional funding to continue the clinical development of our clinical programs, commercialize our product candidates if we receive regulatory approval, and pursue in-licenses or acquisitions of other product candidates. If we receive regulatory approval for any of our product candidates, we expect to incur significant commercialization expenses related to product manufacturing, sales, marketing and distribution, depending on where we choose to commercialize our product candidates.

As of MarchJune 31,30, 2026, the Companywe had outstanding pre-funded warrants to purchase 15,815,253 shares of common stock, each with an exercise price of $0.0001 per share. These warrants can be exercised at any time at the discretion of the holders, subject to certain ownership limitations. While the potential exercise of these pre-funded warrants would result in the issuance of additional shares, thus increasing the total shares outstanding, their nominal exercise price means they are already considered outstanding for purposes of calculating the Company’sour weighted average common stock outstanding and earnings per share. Due to the minimal exercise price, thewe Companydo doesn'tnot anticipate significant additional cash proceeds upon exercise and consequently does not expect the exercise of these warrants to materially affect its liquidity, capital resources, or overall financial condition.

Our management’s discussion and analysis of our financial condition and results of operations is based on our consolidated financial statements, which have been prepared in accordance with generally accepted accounting principles in the United States. The preparation of these consolidated financial statements requires us to make estimates and assumptions that affect the reported amounts of assets and liabilities and the disclosure of contingent assets and liabilities at the date of the consolidated financial statements, as well as the reported expenses incurred during the reporting periods. Our estimates are based on our historical experience and on various other factors that we believe are reasonable under the circumstances, the results of which form the basis for making judgments about the carrying value of assets and liabilities that are not readily apparent from other sources. Actual results may differ from these estimates under different assumptions or conditions. During the threesix months ended MarchJune 31,30, 2026, there were no material changes to our critical accounting policies from those described in our Annual Report Form 10-K filed with the SEC on February 26, 2026.