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

Congress also recently amended the FDCA to require sponsors of a Phase 3 clinical trial, or other “pivotal study” of a new drug or biologic to support marketing authorization, to design and submit a diversity action plan for such clinical trial. The action plan must describe appropriate diversity goals for enrollment, as well as a rationale for the goals and a description of how the sponsor will meet them. Our Phase 3 REGAL trial of GPS for AML patients who have achieved CR2 was initiated before this requirement became effective, but for any future Phase 3 trials we plan to conduct, including any registrational study for SLS009, we must submit a diversity action plan to the FDA by the time we submit plans for such Phase 3, or pivotal study, protocol to the agency for review as part of an IND, unless we are able to obtain a waiver for some or all of the requirements for a diversity action plan. It is unknown at this time how the diversity action plan may affect the planning and timingInitiation of anyour future Phase 3 trial for our product candidates but initiation of such trials may be delayed if the FDA objects to our proposed diversity action plans for any future Phase 3 trial for our product candidates. We may experience difficulties recruiting a diverse population of patients in attempting to fulfill the requirements of any approved diversity action plan.

We are currently investigating SLS009 in combination with aza/ven in a Phase 2a2 clinical trial and we may continue to develop clinical candidates in combination with one or more currently approved cancer therapies or therapies currently in clinical development. Patients may not be able to tolerate our product candidates in combination with other therapies or dosing of our product candidates in combination with other therapies may have unexpected consequences. Even if any of our product candidates were to receive marketing approval or be commercialized for use in combination with other existing therapies, we would continue to be subject to the risks that the FDA, EMA or other comparable foreign regulatory authorities could revoke approval of the therapy used in combination with any of our product candidates, or safety, efficacy, manufacturing or supply issues could arise with these existing therapies. In addition, it is possible that existing therapies with which our product candidates aremay be approved for use could themselves fall out of favor or be relegated to later lines of treatment. This could result in the need to identify other combination therapies for our product candidates or our own products being less successful commercially.

The results of our operations could be adversely affected by general conditions in the global economy, the global financial markets and the global political conditions. The United States and global economies have recently faced growing inflation, higher interest rates and a potential recession. Furthermore, a prolonged economic downturn, including a recession or depression resulting from public health crises such as a pandemic or ongoing political disruption such as the war between Ukraine and RussiaRussia, the conflicts in the Middle East, tensions between China and the conflict involving IsraelTaiwan and Hamasother geopolitical events could result in a variety of risks to our business, including weakened demand for our programs and development candidates, if approved, relationships with any vendors or business partners located in affected geographies and our ability to raise additional capital when needed on acceptable terms, if at all. A weak or declining economy or political disruption, including any international trade disputes, particularly between the United States and China, could also strain our existing or future partnerships, manufacturers or suppliers, possibly resulting in disruption to our clinical trials or supply, or cause our customers to delay making payments for our potential products. Any of the foregoing could seriously harm our business, and we cannot anticipate all of the ways in which the political or economic climate and financial market conditions could seriously harm our business.

Changes in U.S. federal policy that affect the geopolitical landscapelandscape, including tariffs, quotas, trade agreements or other trade restrictions, could give rise to circumstances outside our control that could have negative impacts on our business. OnFor Februaryexample, 1,in April 2025, the UnitedU.S. Statesgovernment imposedannounced a 25%10% tariff on product imports from Canadaalmost all countries and Mexico,individualized whichhigher weretariffs subsequentlyon suspendedcertain forother countries, including a period of one month, and a 10% additional145% tariff on product imports from China. Several tariff announcements have been followed by announcements of limited exemptions and temporary pauses. Historically, tariffs have led to increased trade and political tensions, between not only the United States and China, but also between the United States and other countries in the international community. In response to tariffs, other countries have implemented retaliatory tariffs on U.S. goods. Political tensions as a result of trade policies could reduce trade volume, investment, technological exchange and other economic activities between major international economies, resulting in a material adverse effect on global economic conditions and the stability of global financial markets. Any changes in political, trade, regulatory, and economic conditions, including U.S. trade policies, could have a material adverse effect on our financial condition or results of operations.

If the equity and credit markets deteriorate, it may make any necessary equity or debt financing more difficult to secure, more costly or more dilutive. Failure to secure any necessary financing in a timely manner and on favorable terms could harm our growth strategy, financial performance and stock price and could require us to delay or abandon plans with respect to our business, including clinical development plans. Further, recent developments in the banking industry could adversely affect our business. If the financial institutions with which we do business enter receivership or become insolvent in the future, there is no guarantee that the Department of the Treasury, the Federal Reserve and the FDIC will intercede to provide us and other depositors with access to balances in excess of the $250,000 FDIC insurance limit, that we would be able to access our existing cash, cash equivalents and investments, that we would be able to maintain any required letters of credit or other credit support arrangements, or that we would be able to adequately fund our business for a prolonged period of time or at all, any of which could have a material adverse effect on our business, financial condition and results of operations. We cannot predict the impact that the high market volatility and instability of the banking sector more broadly could have on economic activity and our business in particular. In addition, there is a risk that one or more of our current service providers, manufacturers or other third parties with which we conduct business may not survive difficult economic times, the ongoing conflict between Russia and Ukraine, the warconflicts in the Middle East, tensions between IsraelChina and Hamas,Taiwan and other geopolitical events, the instability of the banking sector, and the uncertainty associated with current worldwide economic conditions, which could directly affect our ability to attain our operating goals on schedule and on budget.

We and the CMOs we rely on will need to conduct significantphase appropriate development work for each product candidate for each target indication for studies, trials and commercial launch readiness. We intend to improve the existing processes for GPS in connection with more advanced clinical trials or commercialization efforts we may undertake in the future. Developing commercially viable manufacturing processes is a difficult, expensive and uncertain task, and there are risks associated with scaling to the level required for advanced clinical trials or commercialization, including cost overruns, potential problems with process scale-up, process reproducibility, stability issues, storage issues, consistency and timely availability of reagents or raw materials. The manufacturing facilities in which our product candidates will be made could be adversely affected by infectious disease outbreaks, pandemics, earthquakes and other natural disasters, equipment failures, labor shortages, lack of adequate temperature controls, power failures, and numerous other factors. We currently estimate that we have sufficient clinical supplies to support our clinical trials, however, this estimate is dependent on patient enrollment rates and a number of other factors and, accordingly, could change. Moreover, current clinical supplies may not be adequate for future clinical studies.

•microbial, viral, or other contaminations in our product candidates or in the manufacturing facilities in which our product candidates are made, which may result in the closure of such manufacturing facilities for an extended period of time to allow for the investigation and remediation of the contamination; and

Judicial Interpretations: Court decisions, particularly those from the United States Supreme Court and the Federal Circuit, play a crucial role in shaping patent law and practice. Shifts in judicial interpretations, such as alterations to the criteria for patent eligibility or obviousness-type double patenting, or the standard for proving patent infringement, may impact prosecution, defense, and enforcement of certain patent claims in our patent portfolio.

In Europe, the European Commission has granted marketing authorizations for severalmultiple biosimilar products pursuant to a set of general and product class-specific guidelines for biosimilar approvals issued over the past few years.approvals. In addition, companies may be developing biosimilar products in other countries that could compete with our products, if approved.

We expect any product candidate which we commercialize will compete with products from other companies in the biotechnology and pharmaceutical industries. There are several biopharmaceutical companies which have approved treatments options in the United States for AML broadly, with different mechanisms of action, including AbbVie/Genentech (Venclexta), Pfizer (Mylotarg), Daiichi-Sankyo (Vanflyta), Rigel Pharmaceuticals (Rezlidhia), Syndax Pharmaceuticals (Revumenib) and Bristol Myers Squibb (Vidaza and Onureg).

Key late-stage pipeline agents that are different from GPS have been granted ODD or Fast Track designation due to the unmet need in AML. Therefore, clinical late-stage companies developing late-stage clinical candidates to treat r/r AML may enter the market before our potential products, such as Delta-Fly Pharma (DFP-10917) and AROG Pharmaceuticals (crenolanib). Actinium Pharmaceuticals, which previously announced in late 2022 / early 2023 positive results in its pivotal Phase 3 trial in adults aged 55 and above with active r/r AML, has since announced that the FDA determined that its Phase 3 trial is not adequate to support a BLA filing for Iomab-B.

With respect to our SLS009 program, we anticipate competition from companies who have been engaged in the clinical development of selective CDK9-targeting therapies. Vincerx Pharma may be a potential competitor in our other indication, PTCL, with enitociclib, its CDK9 inhibitor, as a monotherapy and in combination with venetoclax. There are other companies which are in early development stages for their CDK9 inhibitors and targeting other hematological malignancies or solid tumors, including Sumitomo Dainippon Pharma (TP-1287), Cothera Bioscience (zotiraciclib), and Prelude Therapeutics (PRT2527).

More recently, in August 2022, the IRA was signed into law. Among other things, the IRA (see above “Government Regulation—Healthcare Reform”). If a drug product is selected by CMS for negotiation, it is expected that the revenue generated from such drug will decrease. CMS has begun to implement these new authorities and entered intoannouncing the first setround of agreements with drug and biologic manufacturers for negotiated prices offor the first 10 products,drug products in August 2024, which will become applicable for payment year 2026. The second round of negotiated prices for 15 drug products was announced in November 2025. However, the IRA’s impact on the pharmaceutical industry in the United States remains uncertain, in part because multiple large pharmaceutical companies and other stakeholders (e.g., the U.S. Chamber of Commerce) have initiated federal lawsuits against CMS arguing the program is unconstitutional for a variety of reasons, among other complaints. Those lawsuits are currently ongoing.

In addition, we may be unable to transfer personal data from the EU, UK, and other jurisdictions to U.S or other countries due to limitations on cross-border data flows. In particular, the EEA and the UK have significantly regulated the transfer of personal data to the U.S and other countries whose privacy laws it believes are inadequate. Other jurisdictions may adopt similarly stringent interpretations of their data localization and cross-border data transfer laws. Although there are currently various mechanisms that may be used to transfer personal data from the EEA and the UK to the U.S. in compliance with law, such as the EEA and UK’s standard contractual clauses and the newly-adopted Data Privacy Framework, these mechanisms are subject to legal challenges, and there is no assurance that we can satisfy or rely on these measures to lawfully transfer personal data to the U.S.. If there is no lawful manner for us to transfer personal data from the EEA, the UK or other jurisdictions to the U.S., or if the requirements for a legally-compliant transfer are too onerous, we could face significant adverse consequences, including the interruption or degradation of our operations, the need to relocate part of or all of our business or data processing activities to other jurisdictions at significant expense, increased exposure to regulatory actions, substantial fines and penalties, the inability to transfer data and work with partners, vendors and other third parties, and injunctions against our processing or transferring of personal data necessary to operate our business. Additionally, companies that transfer personal data out of the EEA and the UK to other jurisdictions, particularly to the U.S., are subject to increased scrutiny from regulators, individual litigants, and activist groups.

•general market conditions and other factors unrelated to our operating performance or the operating performance of our competitors, including deteriorating market conditions due to investor concerns regarding inflation and hostilities between Russia and UkraineUkraine, the conflicts in the Middle East, tensions between China and IsraelTaiwan and Hamas.other geopolitical events.

Future legislative and regulatory proposals may materially impact the ability of the FDA and other regulatory agencies to operate as they have historically operated. We cannot be sure whether additional legislative changes or executive orders will be enacted, or whether any of the FDA’s regulations, guidance or interpretations will be changed, or what the impact of such changes on the agency and its scientific review staff, if any, may be. For example, the FDA has experienced significant and rapid fluctuations in leadership and scientific review personnel, which may be key contributing factors in multiple reported delays in agency decision making on marketing applications and agency requests for additional data that are inconsistent with prior regulatory feedback. In addition, negotiations on the next FDA user fee reauthorization package began in mid-2025, and any agreement is expected to enter stakeholder negotiations beginning in mid-2025, with any agreementbe sent to Congress in early 2027 for purposes of initiating the legislative process. Reauthorization of the prescription drug user fee program would need tomust be finalized by Congress by the end of September 2027 in order to avoid a disruption in FDA’s review goals for BLAs and other activities supported by user fees assessed against industry.

In addition, disruptions at the FDA and other agencies may slow the time necessary for new drugs to be reviewed and/or approved by necessary government agencies, which would adversely affect our business. For example, political disputes in Congress may result in a shutdown of the U.S. government and in such cases certain regulatory agencies, such as the FDA and the SEC, would have to furlough critical FDA, SEC and other government employees and stop critical activities. Moreover, government shutdowns or slowdowns can increase the time needed for an agency to complete its review or make final approvals or other administrative decisions. If a prolonged government shutdown were to occur, it could significantly impact the ability of the FDA to timely review and process our regulatory submissions, which could have a material adverse effect on our business and could impact our ability to access the public markets and obtain necessary capital in order to properly capitalize and continue our operations.

We have an ongoing open label randomized Phase 3 clinical trial, the REGAL study, for GPS monotherapy in patients with acute myeloid leukemia, or AML, in the maintenance setting after achievement of second complete remission, or CR2, following successful completion of second-line antileukemic therapy. Patients are randomized to receive either GPS or best available treatment, or BAT. We expect this study will be used as the basis for submission of a Biologics License Application, or BLA, subject to a statistically significant and clinically meaningful trial outcome and agreement with the U.S. Food and Drug Administration, or the FDA. The primary endpoint of the REGAL study is overall survival, or OS. We planned to enroll approximately 125 to 140 patients at approximately 95 clinical sites in North America, Europe and Asia with a planned interim safety, efficacy and futility analysis after 60 events (deaths). In March 2024, we announced the completion of enrollment. In December 2024, we announced that the pre-specified threshold of 60 events (deaths) per the protocol had been reached, triggering the interim analysis to be conducted by the Independent Data Monitoring Committee, or IDMC. In January 2025, we announced that the IDMC had completed pre-specified interim analysis of the REGAL study and had recommended that the study continue without modifications. The next and final analysis will be conducted once 80 events (deaths) are reached. WeIn anticipateDecember 2025, we announced that 80our contract research organization informed us that the pooled number of events willwas be72 reachedas of December 26, 2025. We remain blinded to all efficacy and survival data outcomes and, as no outcomes analyses were performed and no statistical penalty has been incurred, this year.one-time update on the aggregate number of events does not impact future statistical analyses. Because the final analysis is event driven, it is difficult to predict with any certainty and it may occur at a different time than currently expected. We will announce the 80th event when it occurs.

In December 2020, we entered into an exclusive license agreement, or the 3D Medicines Agreement, with 3D Medicines Inc., or 3D Medicines, a China-based biopharmaceutical company developing next-generation immuno-oncology drugs, for the development and commercialization of GPS, as well as the Company’s next generation heptavalent immunotherapeutic GPS+, which is at preclinical stage, across all therapeutic and diagnostic uses in mainland China, Hong Kong, Macau and Taiwan, which we refer to as Greater China. We have retained sole rights to GPS and GPS+ outside of Greater China. In November 2022, we announced that we had agreed with 3D Medicines for 3D Medicines to participate in the REGAL study through the inclusion of approximately 20 patients from mainland China. In December 2022, we entered into a Side Letter Agreement with 3D Medicines, or Side Letter, which together with the 3D Medicines Agreement, details the terms and conditions of 3D Medicines' participation in the REGAL study. Although the REGAL study has completed enrollment as announced in March 2024, in accordance with the predetermined statistical analysis plan, 3D Medicines may still enroll patients in mainland China. The timing of such participation and patient enrollment by 3D Medicines, if at all, cannot be predicted with certainty. As of MarchDecember 15,31, 2025, we have received an aggregate of $10.5 million in upfront and milestone payments under our license agreement with 3D Medicines, or the 3D Medicines Agreement, and a total of $191.5 million in potential future development, regulatory and sales milestones, not including future royalties, remains under the license agreement, which milestones are variable in nature and not under our control. In December 2023, we announced that we had commenced a binding arbitration proceeding against 3D Medicines to resolve a dispute regarding, among other things, the trigger and payment of relevant milestone payments due to us under the 3D Medicines Agreement. See Item 3. Legal Proceedings.

SLS009SLS009, or Tambiciclib: Highly Selective Next Generation CDK9 Inhibitor

We completed a Phase 1 dose-escalating clinical trial in the United States and China for SLS009 in mid-2023 and reported positive safety and efficacy data for both patient cohorts, that is relapsed and/or refractory AML and refractory lymphoma. We also established in the trial a recommended Phase 2 dose, or RP2D, of 60 mg once weekly or 30 mg twice weekly for AML and 100 mg once weekly for lymphomas.

In the second quarter of 2023, we commenced an open label, single arm, multi-center Phase 2a clinical trial with SLS009 in combination with venetoclax and azacitidine, or aza/ven, in patients with AML who failed or did not respond to treatment with venetoclax-based therapies. The trial is evaluating safety, tolerability, and efficacy at two dose levels of SLS009, 45 mg once weekly, and 60 mg once weekly or 30 mg twice a week, in combination with aza/ven. In additionDecember to2024, safetywe andannounced tolerabilitypositive ofdata SLS009from the first 3 cohorts in combination with aza/ven, the efficacyPhase endpoints2a are complete response composite rate and duration of response. Additional endpoints include event free survival, overall survival, and pharmacokinetic and pharmacodynamic assessments.trial.

Non-operating income consists of changes in fair value of our warrant liability and interest income. Interest income primarily reflects the interest earned from our cash and cash equivalents.

•$2.2$2.4 million of decreased external clinical andtrial regulatoryexpenses consultantrelated coststo GPS primarily driven by the completion of enrollment in the REGAL study in the first quarter of 2024;

•$0.6$1.0 million of decreased external clinical trial expenses related to SLS009 primarily driven by the completion of enrollment in REGAL.our Phase 2a trial in the current period;

We anticipate that our research and development expenses will increase in the future as we continue to advanceprepare for a potential BLA filing for GPS following the developmentupcoming final analysis of GPSthe REGAL study and proceed into a randomized Phase 2 clinical trial to include newly diagnosed, front-line AML patients for SLS009.

General and administrative expenses were $12.3 million for the year ended December 31, 2025 compared to $12.4 million for the year ended December 31, 2024 compared to $13.9 million for the year ended December 31, 2023.2024. The $1.5$0.1 million decrease was primarily attributable to a $1.5$0.8 million decrease in employee related expenses, including a $0.5 million decrease in non-cash stock-based compensation, primarily due to a decrease in headcount, a $0.7 million decrease in outside services and public company costs, and a $0.6 million decrease in insurance premiums,expenses which werewas partially offsetdriven by the initial recognition of a $1.1 million one-time severance charge duringin the currentprior period partially offset by a $0.3 million increase in non-cash stock-based compensation and a $0.2$0.7 million increase in legal fees.

The increase in our non-operatingNon-operating income duringof $1.4 million and $0.6 million for the yearyears ended December 31, 20242025 comparedand to2024, the year ended December 31, 2023respectively, was primarily duerelated to a $0.1 million increase in interest income earned from our cash and cash equivalents.

On January 29, 2025, we consummated a registered direct offeringoffering, or the January 2025 Registered Direct Offering, with an institutional investor priced at-the-market under Nasdaq rules, or the January 2025 Registered Direct Offering, pursuant to which we agreed to issue and sell 8,200,000 shares of common stock and 11,485,040 pre-funded warrants exercisable for shares of common stock, together with accompanying warrants to purchase up to 19,685,040 shares of common stock. Each share of common stock and accompanying common warrant were sold together at a combined offering price of $1.27, and each pre-funded warrant and accompanying common warrant were sold together at a combined offering price of $1.2699. The common warrants have an exercise price of $1.20 per share. The net proceeds to us from the January 2025 Registered Direct Offering were approximately $23.1 million, after deducting the placement agents' fees and related offering expenses.

In December 2020, together with our wholly-owned subsidiary, SLSG Limited, LLC, we entered into the 3D Medicines Agreement pursuant to which we granted 3D Medicines a sublicensable royalty-bearing license under certain intellectual property owned or controlled by us, to develop, manufacture and have manufactured, and commercialize GPS and heptavalent GPS product candidates for all therapeutic and other diagnostic uses in the 3DMed Territory. ToAs date,of December 31, 2025, we have received $10.5 million in upfront payments and certain technology transfer and regulatory milestones. A total of $191.5 million in potential future development, regulatory, and sales milestones, not including future royalties, remains under the 3D Medicines Agreement as of December 31, 2024,2025, which milestones are all variable in nature and not under our control. In December 2023, we commenced a binding arbitration proceeding against 3D Medicines, which involves, among other things, the trigger and payment of certain milestone payments due to us. See Part I, Item 3. Legal Proceedings.

As of December 31, 2024,2025, we had an accumulated deficit of $248.1$275.0 million, cash and cash equivalents of $13.9$71.8 million and restricted cash and cash equivalents of $0.1 million. In addition, we had current liabilities of $9.5$7.0 million as of December 31, 2024.2025. We expect that our cash and cash equivalentsequivalents, together with the $42.6 million in proceeds from warrant exercises received subsequent to December 31, 2025, will not be sufficient to fund our current planned operations for at least the next twelve months from the date of issuance of these financial statements.statements, These conditions give rise to a substantial doubt over our ability to continue as a going concern. This going concern assumption is based on management’s assessment of the sufficiency of our current and future sources of liquidity and whether it is probablealthough we willmay bepursue ableadditional tocapital meetresources ourthrough obligationspublic asor theyprivate becomeequity dueor fordebt atfinancings leastor oneby yearentering frominto theadditional datelicense ouragreements consolidatedor financialcollaborations statementswith areother available to be issued, and if not, whether our liquidation is imminent.companies.

We base our expenses related to clinical trials on our estimates of the services received and efforts expended pursuant to quotes and contracts with multiple research institutions and CROs that conduct and manage preclinical studies and clinical trials on our behalf. The financial terms of these agreements are subject to negotiation, vary from contract to contract and may result in uneven payment flows. There may be instances in which payments made to our vendors will exceed the level of services provided and result in a prepayment of the expense. Payments under some of these contracts depend on factors such as the successful enrollment of patients and the completion of clinical trial milestones. In accruing service fees, we estimate the time period over which services will be performed and the level of effort to be expended in each period. If the actual timing of the performance of services or the level of effort varies from the estimate, we adjust the accrual or prepaid accordingly. Although we do not expect its estimates to be materially different from amounts actually incurred, our understanding of the status and timing of services performed relative to the actual status and timing of services performed may vary and may result in reporting amounts that are too high or too low in any particular period. To date, we have not made any material adjustments to our prior estimates of accrued research and development expenses.

This management’s discussion and analysis of financial condition as of MarchJune 31,30, 2026 and results of operations for the three and six months ended MarchJune 31,30, 2026 and 2025, respectively, should be read in conjunction with Management’s Discussion and Analysis of Financial Condition and Results of Operations included in our Annual Report on Form 10-K for the year ended December 31, 2025, as filed with the Securities and Exchange Commission, or SEC, on March 19, 2026, or our 2025 Annual Report, and our other public reports filed with the SEC.

Our lead product candidate, GPS, is a cancer immunotherapeutic agent licensed from Memorial Sloan Kettering Cancer Center, or MSK, that targets the WT1 protein, which is present in 20 or more cancer types. Based on its mechanism of action as a directly immunizing agent, GPS has potential as a monotherapy or in combination with other immunotherapeutic agents to address a broad spectrum of hematologic, or blood, cancers, and solid tumor indications.

On March 31, 2022, we entered into an exclusive license agreement, or the GenFleet Agreement, with GenFleet Therapeutics (Shanghai), Inc., or GenFleet, a clinical-stage biotechnology company developing cutting-edge therapeutics in oncology and immunology, that grants rights to us for the development and commercialization of SLS009, a highly selective small molecule CDK9 inhibitor, across all therapeutic and diagnostic uses worldwide, except for Greater China.China (as defined below).

In the second quarter of 2023, we commenced an open label, single arm, multi-center Phase 2a clinical trial with SLS009 in combination with venetoclax and azacitidine, or aza/ven, in patients with AML who failed or did not respond to treatment with venetoclax-based therapies. The trial is evaluatingevaluated safety, tolerability, and efficacy at two dose levels of SLS009, 45 mg once weekly, and 60 mg once weekly or 30 mg twice a week, in combination with aza/ven. In December 2024, we announced positive data from the first 3 cohorts in the Phase 2a trial.

Following a productive end of Phase 2 meeting, the FDA recommended that we proceed into a clinical trial to include newly diagnosed, first-line AML patients eligible for aza/ven therapy, where the FDA noted clinical benefit might be greatest. The randomized 80-patient Phase 2 clinical trial is currently ongoing and began enrollment in the first quarter of 2026. As of August 10, 2026, there were 28 patients enrolled in the randomized Phase 2 clinical trial of SLS009 in the newly diagnosed, first-line AML setting and enrollment is ongoing in the U.S. The clinical trial will include two groups: predictive biomarker cohort (newly diagnosed patients unlikely to benefit from standard aza/ven therapy based on molecular profiling) and early venetoclax resistance cohort (patients who initiate treatment with aza/ven, but demonstrate confirmed lack of any response after two treatment cycles).

In January 2026, we announced that we entered into an agreement with IMPACT-AML, a European collaborative initiative dedicated to advancing innovative treatments for patients with AML. Under the agreement, the IMPACT-AML network will sponsor and conduct a clinical study evaluating SLS009, enabling access to multiple European clinical sites and patients. IMPACT-AML is a pan-European project andthat builds an inclusive clinical network (STREAM platform) that connectsconnecting patients, clinicians, and researchers to test novel AML therapies and improve patient outcomes. It is part of the prestigious EU Mission Cancer program and a top-tier scientific cluster. The IMPACT-AML project is led by a consortium of major research and clinical institutions in Europe, including IRST (IRCCS Istituto Romagnolo per lo Studio dei Tumori “Dino Amadori”), the University of Bologna, IIS LA FE (Health Research Institute Hospital La Fe), several European AML collaborative groups, and supranational organizations under the umbrella of the European Leukemia Net (ELN), as well as various university hospitals across Europe. By leveraging IMPACT-AML’s existing infrastructure and expertise, we expect to expandexpanded European patient access to SLS009 in a highly cost-efficient manner while supporting broader participation across the clinical program.

In the 2025 Annual Report, we disclosed our critical accounting policies and estimates upon which our consolidated financial statements are derived. There have been no material changes to these policies and estimates since December 31, 2025 that are not included in Note 3 of the accompanying consolidated financial statements for the threesix months ended MarchJune 31,30, 2026. Readers are encouraged to read the 2025 Annual Report in conjunction with this Quarterly Report on Form 10-Q.

Results of Operations for the Three and Six Months Ended MarchJune 31,30, 2026 and 2025

The following tables summarize our results of operations for the three and six months ended MarchJune 31,30, 2026 and 2025 (in thousands):

Research and development expenses were $5.1$6.3 million for the three months ended MarchJune 31,30, 2026 compared to $3.2$3.9 million for the three months ended MarchJune 31,30, 2025.

•$0.2 million of increased external clinical trial expenses related to GPS as we approach the upcoming final analysis of the REGAL study; and

•$0.2 million of increased employee related expenses, stock-based compensation, and facilities and other research and development costs combined; partially offset bycombined.

•$0.2$0.4 million of decreasedincreased external clinical trial expenses related to SLS009 driven by the timing of patient enrollmentGPS as we commenced a randomized Phase 2 clinical trial of newly diagnosed, front-line AML patients atapproach the endupcoming final analysis of the currentREGAL period.study;

General and administrative expenses were $4.1$4.4 million for the three months ended MarchJune 31,30, 2026 compared to $2.9$3.0 million for the three months ended MarchJune 31,30, 2025. The $1.2$1.4 million increase was primarily attributable to athe $0.6one-time recognition in the current period of approximately $1.0 million increasefor inthe reimbursement of an allocated portion of legal fees inand connectionarbitration withcosts from the 3DMed arbitration proceeding in the current period,proceeding, a $0.4 million increase in consulting and public company costs, and a $0.2 million increase in non-cash stock-based compensation driven by an increase in the grant-date fair value of annual equity awards due to an increase in our stock price.price, and a $0.2 million increase in other employee related expenses, which were partially offset by a $0.2 million decrease in facilities and other general and administrative costs.

Non-operating income of $0.8$1.9 million and $0.5 million during the six months ended June 30, 2026 and 2025, respectively, and $1.0 million and $0.3 million during the three months ended MarchJune 31,30, 2026 and 2025, respectively, was related to interest income earned from our cash and cash equivalents.

We did not generate any revenue from product sales during the threesix months ended MarchJune 31,30, 2026 and 2025. Through MarchJune 31,30, 2026, we have only generated licensing revenue from an exclusive license agreement, or the 3D Medicines Agreement.Agreement, with 3D Medicines Inc., or 3D Medicines. Since inception, we have incurred net losses, used net cash in our operations, and have funded substantially all of our operations through proceeds of the sale of equity securities and convertible notes.

During the threesix months ended MarchJune 31,30, 2026, we received approximately $44.1$82.9 million from the exercise of 28.248.8 million outstanding warrants at a weighted average exercise price of $1.56$1.70 per share. Subsequent to March 31, 2026, we received an additional $7.5 million from the exercise of 4.7 million warrants at a weighted average exercise price of $1.60 per share.

As of MarchJune 31,30, 2026, we had an accumulated deficit of $283.4$293.0 million, cash and cash equivalents of $107.1$138.3 million and restricted cash and cash equivalents of $0.1 million. We expect that our cash and cash equivalents, together with the $7.5 million in proceeds from warrant exercises subsequent to March 31, 2026,equivalents will be sufficient to fund our current planned operations for at least the next twelve months from the date of issuance of these financial statements, although we may pursue additional capital resources through public or private equity or debt financings or by entering into additional license agreements or collaborations with other companies.

Management's expectations with respect to its ability to fund current planned operations isare based on estimates that are subject to risks and uncertainties. If actual results are different from management's estimates, we may need to seek additional strategic or financing opportunities sooner than would otherwise be expected. There is no guarantee that any of these strategic or financing opportunities will be executed or executed on favorable terms, and some could be dilutive to existing stockholders. If we are unable to obtain additional funding on a timely basis, we may be forced to significantly curtail, delay, or discontinue one or more of our planned research and development programs or be unable to expand our operations or otherwise prepare for the potential regulatory approval and commercialization of itsour product candidates, assuming positive data.

The following table summarizes our cash flows from operating and financing activities for the threesix months ended MarchJune 31,30, 2026 and 2025 (in thousands):

Net cash used in operating activities of $8.8$16.4 million during the threesix months ended MarchJune 31,30, 2026 was primarily attributable to our net loss of $8.4$18.0 million and a net change in our operating assets and liabilities of approximately $1.4$0.5 million, which were partially offset by net non-cash charges of approximately $1.0$2.1 million. The net change in our operating assets and liabilities is primarily attributable to a decrease in accrued expenses and other current liabilities of approximately $1.3 million, an increase in prepaid expenses and other current assets of approximately $0.6$0.7 million, and a decrease in operating lease liabilities of approximately $0.2$0.3 million, which were partially offset by an increase in accrued expenses and other current liabilities of approximately $0.4 million and an increase in accounts payable of approximately $0.7$0.1 million. Net non-cash charges were driven by $0.8$1.8 million in non-cash stock-based compensation expense and $0.2$0.3 million in non-cash lease expense.

Net cash used in operating activities of $9.1$16.4 million during the threesix months ended MarchJune 31,30, 2025 was primarily attributable to our net loss of $5.8$12.4 million and a net change in our operating assets and liabilities of approximately $3.9$5.3 million, which were partially offset by net non-cash charges of approximately $0.6$1.3 million. The net change in our operating assets and liabilities is primarily attributable to an increase in prepaid expenses and other assets of approximately $1.1$1.4 million, a decrease in accrued expenses and other current liabilities of approximately $2.9$3.4 million, and a decrease in operating lease liabilities of approximately $0.2$0.3 million, whichand werea partially offset by an increasedecrease in accounts payable of $0.3approximately $0.2 million. Net non-cash charges were driven by $0.5$1.0 million in non-cash stock-based compensation expense and $0.1$0.3 million in non-cash lease expense.

We generated $44.2$83.0 million in net cash from financing activities during the threesix months ended MarchJune 31,30, 2026, which was due to approximately $44.1$82.9 million in proceeds from the exercise of warrants and approximately $0.1 million from the purchase of shares of common stock by employees under the amended and restated 2021 Employee Stock Purchase Plan, or the Amended and Restated 2021 ESPP.

We generated $23.6$27.8 million in net cash from financing activities during the threesix months ended MarchJune 31,30, 2025, which was due to approximately $23.0$23.1 million in net proceeds from the January 2025 Registered Direct Offering,Offering $0.5and $4.7 million in proceeds from the exercise of warrants, and $0.1 million from the purchase of shares of common stock by employees under the Amended and Restated 2021 ESPP.warrants.

We have not entered into any off-balance sheet financing arrangements as of MarchJune 31,30, 2026.