NASDAQ: SNDX

We licensed the global rights to revumenib and axatilimab, the first two FDA approved medicines to emerge from our pipeline. We are leading the commercialization and further development of revumenib and working closely with our collaboration partner, Incyte, on the commercialization and further development of axatilimab. We plan to continue to leverage the technical and business expertise of our management team and scientific collaborators to license, acquire and develop additional therapeutics to expand our pipeline.

Our Strategy

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Successfully commercialize Revuforj in the U.S. for R/R acute leukemia patients with a KMT2A translocation and R/R AML patients with an NPM1 mutation; establish Revuforj as the preferred menin inhibitor, leveraging our first mover advantage and robust clinical data supporting the product's profile.

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Advance a robust pipeline of frontline trials of revumenib in combination with standard-of-care therapies to support potential additional listings in the NCCN Clinical Practice Guidelines in Oncology, or NCCN Guidelines®, and/or label expansion opportunities.

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Evaluate opportunities to commercialize Revuforj outside of the United States, potentially on our own or in collaboration with partners who have operations and expertise outside the United States.

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Successfully commercialize Niktimvo in the U.S, in partnership with Incyte, for the treatment of cGVHD patients who have failed at least two prior lines of systemic therapy.

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Continue to advance clinical development programs designed to unlock the opportunity for Niktimvo to address newly diagnosed patients with cGVHD and other diseases, starting with IPF.

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Leverage the technical, clinical, regulatory and business expertise of our management team, scientific collaborators, and organization and network of advisors to license, acquire and develop additional cancer therapies to expand our pipeline and development plans.

We believe that strong execution of our strategy will position us to realize our mission to extend and improve the lives of cancer patients.

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Our Products & Ongoing Development Programs

We have a product portfolio consisting of two FDA-approved products, Revuforj (revumenib) and Niktimvo (axatilimab-csfr), and a robust slate of clinical development programs designed to expand the opportunities for both medicines.

Revuforj (revumenib)

Revuforj in R/R Acute Leukemia with a KMT2A translocation

Revuforj is our oral, first-in-class menin inhibitor that was approved by the FDA in November 2024 for the treatment of R/R acute leukemia with a KMT2A translocation in adult and pediatric patients one year and older. The approval was based on an FDA analysis of 104 patients with R/R acute leukemia with a KMT2A translocation who were treated with Revuforj in the Phase 1/2 AUGMENT-101 trial. In the efficacy population, the rate of complete remission, or CR, plus CR with partial hematological recovery, or CRh, was 21% (22/104 pts; 95% confidence interval [CI]: 13.8%, 30.3%). The median duration of CR+CRh was 6.4 months (95% CI: 2.7, not estimable) and the median time to CR or CRh was 1.9 months (range: 0.9, 5.6 months). 23% (24/104 pts) of patients underwent hematopoietic stem cell transplantation, or HSCT, following treatment with Revuforj. Results from the 104-patient efficacy analysis are consistent with the previously reported, protocol-defined Phase 2 interim analysis of patients with R/R KMT2Ar acute leukemia in the AUGMENT-101 trial (n=57) which were published in the Journal of Clinical Oncology in August 2024.

The original safety evaluation of Revuforj was based on an FDA analysis of 135 patients with R/R acute leukemia with a KMT2A translocation who were treated with Revuforj. The most common adverse reactions (≥20%) including laboratory abnormalities were hemorrhage, nausea, phosphate increased, musculoskeletal pain, infection, aspartate aminotransferase increased, febrile neutropenia, alanine aminotransferase increased, parathyroid hormone intact increased, bacterial infection, diarrhea, differentiation syndrome, electrocardiogram QT prolonged, phosphate decreased, triglycerides increased, potassium decreased, decreased appetite, constipation, edema, viral infection, fatigue, and alkaline phosphatase increased.  Adverse reactions leading to dose reduction or permanent discontinuation were low at 10% and 12% of patients, respectively.

In late November 2024, we launched Revuforj for commercial sale in the United States. In December 2024, revumenib was added to the NCCN Guidelines for AML and acute lymphoblastic leukemia, or ALL, as a category 2A recommendation for R/R acute leukemia with a KMT2A rearrangement. In October 2025, the indication for Revuforj in R/R acute leukemia with a KMT2A translocation was updated to include language referring to the use of an FDA-authorized test to detect KMT2A translocations.

Revuforj in R/R AML with an NPM1 mutation

In September 2025, revumenib was added to the NCCN Guidelines for R/R AML with an NPM1 mutation.

In October 2025, Revuforj received a second approval from the FDA for the treatment of R/R AML with a susceptible NPM1 mutation in adult and pediatric patients one year and older who have no satisfactory alternative treatment options.

The approval of Revuforj in R/R NPM1m AML was based on efficacy data from patients with R/R NPM1m AML in the Phase 2 portion of the pivotal AUGMENT-101 trial. The rate of CR plus CRh was 23% (15/65 pts; 95% CI: 14%, 35%). The median time to CR or CRh response was 2.8 months and the median duration of CR or CRh was 4.5 months. Results from the R/R NPM1m AML cohort in the Phase 2 portion of the AUGMENT-101 trial were published in the journal Blood and presented at the 2025 European Hematology Association, or EHA, Annual Congress.

In connection with the approval of Revuforj in R/R NPM1m AML, the Revuforj U.S. Prescribing Information was updated to include safety data from 241 patients (207 adult and 34 pediatric patients) with R/R acute leukemia with an NPM1 mutation or a KMT2A translocation who were treated with Revuforj in clinical trials. The most common adverse reactions in this combined population were consistent with the previously reported known safety profile of Revuforj. The updated Prescribing Information contains a boxed warning for differentiation syndrome, QTc prolongation, and Torsades de Pointes.

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Revumenib Development Programs

We are studying the use of revumenib in multiple genetic subtypes of acute leukemia across the treatment continuum, including in combination with standard-of-care therapies in newly diagnosed patients with NPM1m and KMT2Ar AML.

Overview of revumenib trials and development pipeline

Multiple trials evaluating revumenib across the acute leukemia treatment continuum are ongoing, such as:

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EVOLVE-2: In the first quarter of 2025, we initiated a pivotal, Phase 3, randomized, double-blind, placebo-controlled trial of revumenib in combination with venetoclax and azacitidine in newly diagnosed NPM1m (primary efficacy analysis population) and KMT2Ar patients who are unfit for intensive chemotherapy. The trial is being conducted in collaboration with the HOVON network, a leading cooperative clinical trial group with extensive experience studying novel therapies for hematologic malignancies. The trial has dual primary endpoints of CR and overall survival, both in NPM1m patients only, to support the potential for accelerated and full approval, respectively.

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REVEAL-ND: In November 2025, we initiated a pivotal, Phase 3, randomized, double-blind, placebo-controlled trial of revumenib in combination with intensive chemotherapy in newly diagnosed NPM1m AML patients. The trial has dual primary endpoints of measurable residual disease, or MRD, negative CR and event free survival to support the potential for accelerated approval and full approval, respectively.

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SAVE: A Phase 1/2 trial evaluating an all-oral combination of revumenib with venetoclax and decitabine/cedazuridine in pediatric and adult patients with newly diagnosed and R/R AML or mixed-lineage acute leukemia harboring either NPM1m, KMT2Ar, or NUP98r alterations. The trial is being conducted by investigators from MD Anderson Cancer Center. New data presented at the 2025 American Society of Hematology, or ASH, Annual Meeting from the first cohort of newly diagnosed patients showed a CR rate of 76% (16/21), an overall response rate, or ORR, of 86% (18/21), and a MRD negativity rate among responders of 100% (18/18).

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Intensive chemotherapy: Two ongoing Phase 1 trials, referred to as the 708 and NCI trial, are evaluating the combination of revumenib with intensive chemotherapy (7+3) in newly diagnosed NPM1m or KMT2Ar acute leukemia patients. Preliminary data presented from both trials at the 2025 ASH Annual Meeting showed that the safety profile of the combination was consistent with the profile for intensive chemotherapy alone, along with high rates of response and MRD negativity.

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BEAT AML: A Phase 1 trial evaluating the combination of revumenib with venetoclax and azacitidine in newly diagnosed older adults (≥60 years) with NPM1m or KMT2Ar AML. The trial is being conducted as part of the Leukemia & Lymphoma Society's Beat AML® Master Clinical Trial. Data presented at the

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2025 EHA Annual Congress and simultaneously published in the Journal of Clinical Oncology showed a CR rate of 67% (29/43), an ORR of 88% (38/43), and a MRD negativity rate of 100% (37/37) among responders.

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Post-transplant maintenance: A Phase 1 trial, referred to as the Ball study, is evaluating the safety and preliminary efficacy of revumenib as post-transplant maintenance after HSCT in patients with KMT2Ar or NPM1m acute leukemia. The trial is being conducted by investigators from the City of Hope Medical Center.

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Break Through Cancer: A Phase 2 trial studying whether the combination of revumenib and venetoclax can eliminate MRD in patients with AML and extend progression-free survival. The trial is being conducted by Break Through Cancer, a collaboration between leading U.S. cancer research centers.

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INTERCEPT: A Phase 1 trial evaluating the use of novel therapies, including revumenib, to target MRD and early relapse in AML. The trial is being conducted by the Australasian Leukaemia and Lymphoma Group as part of the INTERCEPT AML master clinical trial. Data presented at the 2024 ASH Annual Meeting showed that 54% (6/11) of patients had MRD reduction at any time, including 36% (4/11) who achieved MRD negativity.

In addition to the ongoing trials described above, we expect to initiate the RAVEN trial in the second half of 2026. RAVEN is a Phase 2 collaborative trial of revumenib in combination with venetoclax and azacitidine in newly diagnosed KMT2Ar patients who would be considered eligible, or fit, for intensive chemotherapy. The RAVEN trial seeks to explore if the combination can provide high rates of clinical activity without the toxicity associated with intensive chemotherapy.

Revumenib in MF

We plan to initiate a program in 2026 designed to generate proof-of-principle clinical data with revumenib in MF. This program builds on preclinical data presented at the 2025 ASH Annual Meeting which showed that menin inhibition has the potential for disease-modifying activity by reversing key pathologic features of myeloproliferative neoplasms, or MPNs, including those seen in MF.

Revumenib in colorectal cancer (CRC)

In January 2026, we reported Phase 1 results from a Phase 1/2 proof-of-concept trial designed to assess the safety, tolerability, and anti-tumor activity of revumenib in patients with advanced CRC and other solid tumors at the ASCO Gastrointestinal Cancer Symposium. The study met the Phase 1 primary endpoint, demonstrating that revumenib was well tolerated. Limited anti-tumor efficacy was observed, with no patients achieving a clinical response and a 10.5% disease control rate. We have decided not to pursue further development of revumenib in CRC.

Niktimvo (axatilimab)

Niktimvo (axatilimab-csfr) is our first-in-class CSF-1R-blocking antibody that was approved by the FDA in August 2024 for the treatment of cGVHD after failure of at least two prior lines of systemic therapy in adult and pediatric patients weighing at least 40 kg.

The FDA approval was based on data from the global AGAVE-201 study evaluating the safety and efficacy of Niktimvo in 241 adult and pediatric patients with refractory cGVHD who received at least two prior lines of systemic therapy. The trial met the primary endpoint across all cohorts receiving Niktimvo. Results from the study showed durable responses across all organs studied and patient subgroups. Among patients who received Niktimvo at the approved dose of 0.3 mg/kg every two weeks (n=79), 75% achieved an overall response rate (ORR) within the first six months of treatment, with a median time to response of 1.5 months. Additionally, 60% maintained a response at 12 months (measured from first response to new systemic therapy or death, based on the Kaplan Meier estimate). The trial also met a key exploratory endpoint, with a majority (56%) of patients achieving a ≥7-point improvement in the modified Lee Symptom Scale score. Organ-specific complete and partial responses were demonstrated across all organs studied that are affected by cGVHD, including lower gastrointestinal, or GI, upper GI, esophagus, joints/fascia, mouth, lungs, liver, eyes and skin. The most common (≥15%) adverse reactions,

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including laboratory abnormalities, were increased aspartate aminotransferase, infection (pathogen unspecified), increased alanine aminotransferase, decreased phosphate, decreased hemoglobin, viral infection, increased gamma glutamyl transferase, musculoskeletal pain, increased lipase, fatigue, increased amylase, increased calcium, increased creatine phosphokinase, increased alkaline phosphatase, nausea, headache, diarrhea, cough, bacterial infection, pyrexia and dyspnea.

In September 2024, the pivotal data from the AGAVE-201 trial were published in the New England Journal of Medicine. In August 2024, axatilimab-csfr was added to the latest NCCN Guidelines as a category 2A recommendation for the treatment of chronic GVHD after the failure of at least two prior lines of systemic therapy in adult and pediatric patients weighing at least 40 kg.

In late January 2025, we launched Niktimvo for commercial sale in the U.S. in partnership with Incyte and in accordance with the collaboration agreement and license agreement with Incyte described below under the heading “Collaborations - Incyte Collaboration and License Agreement.” Under the agreement, we are co-commercializing Niktimvo along with Incyte.

Axatilimab Development Programs

Axatilimab is in development for the treatment of newly diagnosed chronic GVHD patients and for other fibrotic diseases, such as IPF.

Axatilimab is a monoclonal antibody targeting CSF-1R, a cell surface protein thought to control the survival and function of monocytes and macrophages. Axatilimab binds with high affinity to CSF-1R and blocks the binding of the two known CSF-1R ligands CSF-1 and IL-34. CSF-1R is expressed on the surface of specific immune cells known as macrophages and their precursor cells known as monocytes. CSF-1R signaling on these cells has been demonstrated in preclinical studies conducted in animal models of skin and lung cGVHD to be the key regulatory pathway involved in the expansion and infiltration of the macrophages that mediate fibrosis and the cGVHD disease process. Blocking CSF-1R activity with an experimental CSF-1R antibody in these studies was shown to prevent and treat the symptoms of cGVHD. We believe that by inhibiting CSF-1R activation on monocytes and macrophages, axatilimab also has the potential to be used to treat other fibrotic diseases where monocyte-derived macrophages have been shown to play a significant role.

Our near-term focus is to investigate the potential for axatilimab to provide meaningful clinical benefit earlier in the treatment of cGVHD and to establish proof-of-concept for the use of axatilimab to treat other fibrotic diseases where monocyte-derived macrophages have been shown to play a role.

Overview of axatilimab trials and development pipeline

*Trials led by Incyte. List is not inclusive of ongoing ex-U.S. trials.

Axatilimab for the treatment of newly diagnosed cGVHD patients

Our partner, Incyte, has initiated two clinical trials studying the use of axatilimab in combination with standard of care cGVHD therapies in the frontline setting.

One trial is a Phase 2, open-label, randomized, multicenter trial of axatilimab in combination with ruxolitinib in patients 12 years of age and older with newly diagnosed cGVHD. Interim safety data presented at the 2025 ASH Annual Meeting showed that the combination was well tolerated. Topline data from the trial is anticipated in early 2027.

The second trial, referred to as AXemplify-357, is a Phase 3, randomized, double-blind, placebo-controlled, multi-center trial that will investigate the use of axatilimab in combination with corticosteroids as initial treatment for cGVHD. Topline data from the trial is anticipated in early 2028.

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Axatilimab for the treatment of IPF

In the first quarter of 2026, we completed enrollment in MAXPIRe, our randomized, double-blind, placebo-controlled, 26-week, Phase 2 trial of axatilimab on top of standard-of-care therapies in patients with IPF. The ongoing trial will assess the efficacy, safety and tolerability of axatilimab. We expect to report topline data from the trial in the fourth quarter of 2026.

Entinostat

Entinostat is our oral, small molecule product candidate that has direct effects on both cancer cells and immune regulatory cells, potentially enhancing the body’s immune response to tumors. In March 2007, we entered into a license agreement with Bayer Schering Pharma AG, or Bayer, for a worldwide, exclusive license to develop and commercialize entinostat and any other products containing the same active ingredient. We have deprioritized the development of entinostat, but maintain a license, development and commercialization agreement, or the Eddingpharm License Agreement, with Eddingpharm Investment Company Limited, or Eddingpharm, under which we granted Eddingpharm an exclusive license under our intellectual property rights to develop and commercialize entinostat in China and certain other Asian countries. In April 2024, entinostat received marketing approval in China.

Disease and Market Overviews

KMT2A-Rearranged (KMT2Ar) Acute Leukemia

KMT2Ar, also known as mixed lineage leukemia rearranged, acute leukemias arise by rare, spontaneous translocations at the MLL1 locus (11q23). It is estimated that approximately 10% of AML and ALL harbor a KMT2A rearrangement with a worldwide incidence of approximately 5,000 to 7,000 cases per year. KMT2Ar acute leukemia is routinely diagnosed through currently available cytogenetic or molecular diagnostic techniques.

KMT2A-rearrangements give rise to an aggressive form of acute leukemia that is associated with a very poor prognosis and high relapse rates. It is estimated that more than 95% of patients with KMT2Ar acute leukemia have a KMT2A translocation, a type of rearrangement that occurs when part of one chromosome breaks and fuses to a different chromosome. More than half of patients with KMT2Ar acute leukemia will relapse after receiving conventional frontline therapies, with a median overall survival, or OS, of less than one year. With third line treatment or beyond, only 5% of patients achieve complete remission, and the median OS is less than three months.

Revuforj is the first and only FDA-approved treatment for R/R acute leukemia with a KMT2A translocation. Currently there are several other clinical-stage menin inhibitors in development for the treatment of KMT2Ar acute leukemias.

Mutant NPM1 (NPM1m) Acute Myeloid Leukemia (AML)

Mutations in the NPM1 gene are the most common genetic alteration in adult AML and are observed in approximately 30% of cases. Patients with R/R NPM1m AML have a poor prognosis and high unmet need.

Like KMT2Ar acute leukemia, NPM1m is readily diagnosed as part of the standard AML patient work-up today. Revuforj is the first and only treatment FDA approved in both adults and children with R/R NPM1m AML. There is one other menin inhibitor, Komzifti™ (ziftomenib), that is FDA approved in adults only with R/R NPM1m AML. There are several additional clinical stage agents currently advancing as potential treatments for NPM1m AML.

Myelofibrosis (MF)

MF is a subtype of a group of blood cancers called MPNs. MF affects the bone marrow and the production of blood cells. It is characterized by bone marrow fibrosis, extramedullary hematopoiesis, splenomegaly, cytopenias, and systemic symptoms. MF is estimated to affect approximately 16,000 to 20,000 patients in the United States.

There are currently four FDA approved therapies for MF, Jakafi® (ruxolitinib), Inrebic® (fedratinib), Vonjo® (pacritinib), and Ojjaara® (momelotinib), all of which are JAK inhibitors. While these drugs reduce symptom burden and spleen volume, they do not substantially reduce the degree of bone marrow fibrosis, and most patients stop responding to JAK inhibitors within two to three years. Therefore, new therapeutic strategies are needed.

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Preclinical data presented at the 2025 ASH Annual Meeting showed that menin inhibition has the potential for disease-modifying activity by reversing key pathologic features of MPNs, including those seen in MF. In vitro studies showed that revumenib caused a decrease in megakaryocyte progenitor cells and led to fewer mature megakaryocytes without affecting other blood cell lineages. In vivo data from MPN mouse models showed that revumenib lowered leukocyte and platelet counts, reduced megakaryocyte numbers in the bone marrow, ablated bone marrow fibrosis, normalized hemoglobin and hematocrit levels, and reduced spleen size. Certain effects were enhanced when revumenib was combined with ruxolitinib. These preclinical data provide rationale for the further investigation of menin inhibition in the treatment of MF.

Chronic Graft-Versus-Host Disease (cGVHD)

cGVHD, an immune response of the donor-derived hematopoietic cells against recipient tissues, is a serious, potentially life-threatening complication of allogeneic HSCT that can last for years. cGVHD is a leading cause of significant morbidity and mortality after HSCT and is estimated to develop in approximately 42% of transplant recipients, affecting approximately 17,000 patients in the U.S. Of those patients who develop chronic GVHD, nearly 50% require at least three lines of treatment, emphasizing the need for additional effective treatment options. cGVHD typically manifests across multiple organ systems, with the skin and mucosa being commonly involved, and is characterized by the development of fibrotic tissue.

cGVHD has historically been managed by off-label treatments. However, in the past several years, the FDA has approved three drugs, Imbruvica® (ibrutinib), Rezurock® (belomosidil) and Jakafi® (ruxolitinib), for use in patients with cGVHD after failure of one or more prior lines of systemic therapy. All three of these drugs may compete with Niktimvo in patients diagnosed with cGVHD. The first line of therapy for cGVHD is typically corticosteroids, though approximately 50% of patients may require treatment with additional systemic therapies, such as extracorporeal photopheresis, cytostatic agents such as mycophenolate moftetil, methotrexate, and immunomodulators such as rituximab, IL-2. Imbruvica® (ibrutinib), a BTK inhibitor, was the first FDA-approved therapy for cGVHD and is indicated for use after one or more lines of therapy. Imbruvica received approval based on Phase 1/2 clinical trial data that showed a 68% overall response rate, with 48% of responses lasting 20 weeks or longer and reduced dependence on steroids for most patients. Prior to the recent FDA approval of Niktimvo (axatilimab-csfr), the FDA had previously approved two other drugs, Rezurock® (belomosidil), for use in patients with cGVHD after failure of at least two prior lines of systemic therapy, and Jakafi® (ruxolitinib), for use in patients with cGVHD after failure of one or more prior lines of systemic therapy. While the other agents have shown a benefit in improving symptoms of this disease, none have demonstrated an improvement in long-term outcomes and a significant unmet medical need still remains for this patient population. Additionally, the other previously approved agents are believed to exert their effect through T- and B-cells, with minimal impact on macrophages. By inhibiting the work of monocyte-derived macrophages, axatilimab provides a differentiated way to treat cGVHD, which we expect to ultimately have a more pronounced impact on the fibrotic process. We also believe that shifting CSF-1R inhibition earlier in the treatment phase of cGVHD, to minimize formation of fibrotic tissue, could have a meaningful long-term impact on the disease process itself.

Idiopathic Pulmonary Fibrosis (IPF)

IPF is a specific form of chronic, fibrosing, interstitial pneumonia limited to the lungs with a median survival of approximately three to five years after diagnosis. IPF has an estimated prevalence of 281,000 people among the seven major market countries. IPF incidence and prevalence increase with age and are higher among males. Although relatively rare, the incidence of IPF is increasing, likely due to an increasing understanding of the disease and the recent development of uniform diagnostic criteria.

There are currently three FDA approved therapies for IPF, Ofev® (nintedanib), Esbriet® (pirfenidone), and Jascayd® (nerandomilast). Despite these recent advances, the unmet medical need in IPF remains high, with a five-year mortality rate of 50% to 70% with deaths occurring mainly due to respiratory failure. Lung transplantation remains the only curative treatment option, but less than five percent of IPF patients undergo lung transplantation. There is an urgent need for new and more effective treatments for IPF that can address the limitations of current treatment options, improve mortality, and quality of life.

Growing evidence suggests macrophages are critical regulators of lung fibrosis. Recent work has established a role for monocyte-derived macrophages as the pathogenic population of cells required for the development of fibrosis and that drive the fibrotic process. Reducing the circulating levels of pathogenic monocyte-derived macrophage precursors or inhibiting their activation in tissues provides an opportunity to therapeutically intervene

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and directly inhibit fibrosis. Recent experiments have demonstrated that the monocyte-derived, pro-fibrotic macrophages are CSF-1-dependent and CSF-1R inhibition through anti-CSF-1R antibody can block fibrosis in fibrotic disease models. We believe that using axatilimab to inhibit the work of monocyte-derived macrophages may provide a differentiated way to treat IPF, and could result in a more pronounced impact on the fibrotic process.

Collaborations

Incyte Collaboration and License Agreement

In September 2021, the Company entered into the Incyte License and Collaboration Agreement, or the Incyte License, with Incyte covering the worldwide development and commercialization of axatilimab. Also in September 2021, the Company entered into a share purchase agreement with Incyte, or the Incyte Share Purchase Agreement. These agreements are collectively referred to as the Incyte Agreements. Under the terms of the Incyte Agreements, Incyte received exclusive commercialization rights outside of the United States, subject to certain royalty and milestone payment obligations set forth below. In the United States, Incyte and the Company are co-commercializing axatilimab as Niktimvo (axatilimab-csfr) and share equally the profits and losses from these co-commercialization efforts.

The Company and Incyte have agreed to continue to co-develop axatilimab and to share development costs associated with global and additional U.S.-specific clinical trials, with Incyte responsible for 55% of such costs and the Company responsible for 45% of such costs. Each company will be responsible for funding any of its own independent development activities. Incyte is responsible for 100% of future development costs for trials that are specific to non-U.S. countries. All development costs related to the collaboration will be subject to a joint development plan.

Under the terms of the Incyte Agreements, in December 2021, Incyte paid the Company a non-refundable cash payment of $117.0 million and the Company issued 1,421,523 shares of common stock with an aggregate purchase price of $35.0 million, or $24.62 per share. Additionally, under the terms of the Incyte Agreements, the Company was eligible, upon execution, to receive up to $220.0 million in future contingent development and regulatory milestones and up to $230.0 million in commercialization milestones as well as tiered royalties ranging in the mid-teens percentage on net sales of the licensed product comprising axatilimab in Europe and Japan and low double digit percentage in the rest of the world outside of the United States. The Company’s right to receive royalties in any particular country will expire upon the last to occur of (a) the expiration of licensed patent rights covering the licensed product in that particular country, (b) a specified period of time after the first post - marketing authorization sale of a licensed product in that country, and (c) the expiration of any regulatory exclusivity for that licensed product in that country.

License Agreements

Vitae Pharmaceuticals, Inc.

In October 2017, we entered into a license agreement, or the Vitae License Agreement, under which we were granted an exclusive, sublicensable, worldwide license to a portfolio of preclinical, orally available, small molecule inhibitors of the Menin–KMT2A binding interaction, or the Menin Assets. Under the Vitae License Agreement, we are required to pay AbbVie up to $99.0 million in one-time development and regulatory milestone payments over the term of the Vitae License Agreement, subject to the achievement of certain milestone events. In the event that we or any of our affiliates or sublicensees commercializes the Menin Assets, we will also be obligated to pay Vitae low single to low double-digit percentage royalties on sales, subject to reduction in certain circumstances, as well as up to an aggregate of $70.0 million in potential one-time, sales-based milestone payments based on achievement of certain annual sales thresholds. We are solely responsible for the development and commercialization of the Menin Assets. Each party may terminate the Vitae License Agreement for the other party’s uncured material breach or insolvency, and we may terminate the Vitae License Agreement at any time upon advance written notice to Vitae. Vitae may terminate the Vitae License Agreement if we or any of our affiliates or sublicensees institutes a legal challenge to the validity, enforceability, or patentability of the licensed patent rights. Unless terminated earlier in accordance with its terms, the Vitae License Agreement will continue on a country-by-country and product-by-product basis until the later of: (i) the expiration of all of the licensed patent rights in such

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country; (ii) the expiration of all regulatory exclusivity applicable to the product in such country; and (iii) 10 years from the date of the first commercial sale of the product in such country.

UCB

In 2016, the Company entered into a license agreement, or the UCB License Agreement, as amended from time to time, with UCB, under which UCB granted to the Company a worldwide, sublicensable, exclusive license to UCB6352, which the Company refers to as axatilimab, an anti-CSF-1R monoclonal antibody. Under the UCB License Agreement, the Company is required to pay UCB up to $119.5 million in one-time development and regulatory milestone payments over the term of the UCB License Agreement, subject to the achievement of certain milestone events. The Company will also be obligated to pay UCB low double-digit percentage royalties on sales, subject to reduction in certain circumstances, as well as up to an aggregate of $250.0 million in potential one-time, sales-based milestone payments based on achievement of certain annual sales thresholds. Under certain circumstances, the Company may be required to share a percentage of non-royalty income from sublicensees, subject to certain deductions, with UCB. The Company is solely responsible for the development and commercialization of axatilimab, except that UCB was responsible for performing a limited set of transitional chemistry, manufacturing and control tasks related to axatilimab. Each party may terminate the UCB License Agreement for the other party’s uncured material breach or insolvency, and the Company may terminate the UCB License Agreement at any time upon advance written notice to UCB. UCB may terminate the UCB License Agreement if the Company or any of its affiliates or sublicensees institutes a legal challenge to the validity, enforceability, or patentability of the licensed patent rights. Unless terminated earlier in accordance with its terms, the UCB License Agreement will continue on a country-by-country and product-by-product basis until the later of: (i) the expiration of all of the licensed patent rights in such country; (ii) the expiration of all regulatory exclusivity applicable to the product in such country; and (iii) 10 years from the date of the first commercial sale of the product in such country.

Bayer Pharma AG (formerly known as Bayer Schering Pharma AG)

In March 2007, the Company entered into a license agreement with Bayer for a worldwide, exclusive license to develop and commercialize entinostat and any other products containing the same active ingredient. The Company will pay Bayer royalties on a sliding scale based on net sales, if any, and make future milestone payments to Bayer of up to $150.0 million in the event that certain specified development and regulatory goals and sales levels are achieved.

Eddingpharm Investment Company Limited

In April 2013, the Company entered into the Eddingpharm License Agreement to develop and commercialize entinostat in China and certain other Asian countries. Eddingpharm will pay the Company royalties on a sliding scale based on net sales, if any, and make future milestone payments up to $10.0 million in the event that certain specified development and regulatory goals are achieved.

Royalty Financing with Royalty Pharma

On November 4, 2024, we entered into a Purchase and Sale Agreement, or Purchase and Sale Agreement, with Royalty Pharma Development Funding, LLC, or Royalty Pharma, pursuant to which Royalty Pharma purchased rights to certain revenue streams from net sales of products comprising or containing axatilimab (including Niktimvo) by Syndax, its affiliates and its licensees in the United States and its respective territories, districts, commonwealths and possessions (including Guam and Puerto Rico) in exchange for an upfront fee of $350 million.

Pursuant to the Purchase and Sale Agreement, Royalty Pharma purchased the right to receive a percentage of net sales equal to a royalty rate of 13.8% on quarterly net sales of Niktimvo in the United States and its respective territories; provided that the royalty rate is subject to certain adjustments based on future aggregate net sales of the product in the Territory, the Revenue Participation Right. Aggregate payments made to Royalty Pharma in respect of the Revenue Participation Right will be capped at $822.5 million, or the Royalty Cap.

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The Purchase and Sale Agreement contains customary representations, warranties and indemnities of the Company and Royalty Pharma and customary covenants relating to the royalty payments, including the grant of a back-up security interest in the purchased royalties and certain assets related to the product and restrictions on the incurrence of additional indebtedness and on the existence of liens on our assets related to the product. Upon a change of control, we will have the right, but not the obligation, to repurchase the Revenue Participation Right at a repurchase price set forth in the Purchase and Sale Agreement. In addition, the Purchase and Sale Agreement provides that if certain events of default occur, including certain bankruptcy events or certain termination events with respect to our license agreement with UCB Biopharma Srl, Royalty Pharma may require us to repurchase Royalty Pharma’s interests in the Revenue Participation Right at a repurchase price equal to the Royalty Cap.

Sales and Marketing

To support the commercialization of Revuforj and Niktimvo in the United States, we have established a robust customer-facing team comprising highly experienced professionals with extensive experience in hematology and oncology and new product launches. Our targeted sales force focuses on a well-defined group of medical hematologists and oncologists and transplant physicians, primarily in academic and community settings, who are responsible for the care and treatment of cancer patients. For Revuforj, we manage sales, marketing and distribution through internal resources and third-party relationships. In accordance with our agreement, Incyte leads the commercialization of axatilimab globally and we are co-commercializing Niktimvo in the United States. Outside the United States, we plan to rely on our current partners and plan to seek additional pharmaceutical partners for development as well as sales and marketing activities.

Manufacturing

We do not own or operate manufacturing facilities for the production of revumenib, axatilimab, or entinostat, and we do not have plans to develop our own manufacturing operations in the foreseeable future. We currently rely on third-party contract manufacturers as well as Incyte for all of our required raw materials, active pharmaceutical ingredients and finished product for our preclinical research, clinical trials, and commercial supply. Development and commercial quantities of any products that we develop will need to be manufactured in facilities, and by processes, that comply with the requirements of the FDA and the regulatory agencies of other jurisdictions in which we are seeking approval.

Intellectual Property

Patents and Property Rights

Through licensed intellectual property and our owned intellectual property, we seek patent protection in the United States and internationally for our product candidates, their methods of use and processes for their manufacture, as well as for other technologies, where appropriate. Our policy is to actively seek to protect our proprietary position by, among other things, filing patent applications in the United States and abroad claiming our proprietary technologies that are important to the development of our business. We also rely on trade secrets, know-how, continuing technological innovation and in-licensing opportunities to develop and maintain our proprietary position.

We cannot be sure that patents will be granted with respect to any of our owned or licensed pending patent applications or with respect to any patent applications filed by us or our licensors in the future, nor can we be sure that any of our existing owned or licensed patents or any patents that may be granted to us or to our licensors in the future will protect our technology. Our success will depend significantly on our ability to obtain and maintain patent and other proprietary protection for the technologies that we consider important to our business, defend our patents, preserve the confidentiality of our trade secrets, operate our business without infringing the patents and proprietary rights of third parties, and prevent third parties from infringing our proprietary rights.

Axatilimab Patent Portfolio

We in-licensed from UCB a patent portfolio directed to axatilimab. As of December 31, 2025, the in-licensed axatilimab composition-of-matter patent portfolio included two granted U.S. patents, 35 granted non-U.S. patents, including a granted Eurasian patent which has been validated in 3 countries and two granted EP patents which have been validated in 37 countries each, and 6 non-U.S. pending patent applications. The in-licensed granted patents

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covering axatilimab, and any non-U.S. pending applications should they issue, will expire in August 2034 or later should patent term extension be granted.

Our in-licensed patent portfolio also includes patents and patent applications directed to methods for the treatment and/or prophylaxis of fibrotic disease by administration of an inhibitor of CSF-1R activity, methods for the treatment and/or prophylaxis of inflammatory bowel disease, or IBD, by administration of an inhibitor of CSF-1R activity, and liquid pharmaceutical compositions of anti-CSF-1R antibodies. As of December 31, 2025, the in-licensed method of use patent family included 11 granted non-U.S. patents, including a granted EP patent which has been validated in 7 countries. These in-licensed granted patents covering axatilimab, will expire in August 2034 or later should patent term extension be granted. As of December 31, 2025, the in-licensed liquid pharmaceutical compositions of anti-CSF-1R antibodies patent family included 1 granted U.S. patent, 17 granted non-U.S. patents including a granted EP patent which has been validated in 33 countries. These in-licensed granted patents covering axatilimab, and any non-U.S. pending applications should they issue, will expire in February 2036 or later should patent term extension be granted.

Our owned axatilimab patent portfolio includes one granted U.S. Patent, three granted non-U.S. patents, one pending U.S. patent application and five non-U.S. patent applications directed to combinations of entinostat and axatilimab. The granted U.S. patent will expire in January 2039 (including a patent term adjustment period of 237 days). Further, the non-U.S. granted patents and any pending applications should they issue, will expire in May 2038 or later should patent term extension be granted. Our owned axatilimab patent portfolio also consists of patent applications directed to the treatment regimens and methods of using axatilimab includes one allowed U.S. patent application, one allowed non-U.S. patent application, and 19 non-U.S. patent applications. Further, our owned axatilimab patent portfolio consists of patent applications directed to methods of treating chronic graft-versus-host disease-related bronchiolitis obliterans syndrome using an anti-colony stimulating factor 1 receptor antibody, which include one pending U.S. patent application, one pending non-U.S. patent application, and one pending Patent Cooperation Treaty, or PCT, application. If any one of these applications were to issue as one or more patents, these patents would expire between December 2040 and May 2044 or later should patent term extension be granted.

Menin Asset Patent Portfolio

We in-licensed from Vitae, a patent portfolio directed to a series of selective preclinical inhibitors targeting the binding interaction of menin with MLL-r. As of December 31, 2025, the in-licensed portfolio includes five granted U.S. patents, U.S. Patent Nos. 12,312,359; 11,479,557; 10,683,302; 11,739,085; and 10,899,758; 30 granted non-U.S patents, including a granted European patent, which was validated in 30 member states and another granted European patent which was validated in 15 member states; two pending U.S. applications; and 20 non-U.S. pending patent applications covering composition of matter and methods of treating, e.g., MLL. The in-licensed granted patents, and any pending application should they issue, are expected to expire between June 2037 and September 2037 or later should patent term extension be granted.

Our owned menin patent portfolio consists of 14 pending non-U.S. patent applications and one allowed U.S. patent application, directed to combinations of a menin inhibitor and a CYP3A inhibitor for the treatment of various cancers. Our owned menin patent portfolio also consists of one pending U.S. non-provisional application, one pending PCT application, and one pending non-U.S. patent application directed to the salts and polymorphic forms of menin inhibitors and pharmaceutical combinations thereof. Furthermore, our owned menin portfolio includes 15 pending non-U.S. patent applications and one pending U.S. patent application directed to methods of treating colorectal cancer in a subject in need thereof with a menin-MLL inhibitor. We also own two pending non-U.S. patent applications and one pending PCT application, covering composition of matter and methods of treating cancer and other diseases mediated by the menin-MLL interaction. If any of these pending applications were to issue as one or more patents, these patents would expire between April 2041 and November 2044 or later should patent term extension be granted.

We co-own with Vitae one granted U.S. patent, eighteen pending non-U.S. patent applications, and one pending U.S. patent application, covering composition of matter and methods of treating cancer and other diseases mediated by the menin-MLL interaction. The granted patent and any pending applications should they issue, are expected to expire in May 2042 or later should patent term extension be granted.

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We also own two pending PCT applications, two pending non-U.S. patent applications, one pending U.S. non-provisional patent application, and six U.S. provisional applications covering composition of matter and methods of treating cancer and other diseases mediated by the menin-MLL interaction. Should these pending applications issue as one or more patents, these patents would expire between December 2045 and February 2046 or later should patent term extension be granted.

We also co-own with St. Jude Children's Research Hospital, Inc. one pending PCT application, covering methods of using menin inhibitors or combinations of a menin inhibitor and a second therapeutic agent. Should this pending application issue as one or more patents, these patents would expire in 2045 or later should patent term extension be granted. We also co-own with Board of Regents, The University of Texas System six pending non-U.S. patent applications, one pending U.S. patent application, covering methods of treating cancer with combinations, including menin inhibitors and Bcl-2 inhibitors.

Entinostat Patent Portfolio

We have protected entinostat with multiple layers of patents. As of December 31, 2025, our portfolio included two owned pending U.S. non-provisional patent applications, five owned granted U.S. patents, U.S. Patent Nos. 10,226,472; 11,324,822; 11,397,184; 12,168,054; and 12,000,829; which expire in August 2032, March 2036, October 2036; January 2039; and September 2041, respectively, or later should patent term extension be granted, directed to methods of treating or selecting a patient for treatment with combinations comprising entinostat and another therapeutic agent, 28 granted non-U.S. patents (including one European patent validated in five countries), and 12 owned non-U.S. pending patent applications. Our owned entinostat patent portfolio includes pending U.S. and/or non-U.S. patent applications directed to methods of treating cancer patients by administration of entinostat and exemestane, treatments with entinostat combined with anti PD-1 or anti PD-L1 antibodies, entinostat and CSF-1 or CSF-1R combination therapies (also discussed above in the Axatilimab Patent Portfolio) and patient selection for combination therapy comprising entinostat and a second therapeutic agent. The granted patents would otherwise expire between August 2032 and May 2039 or later should patent term extension be granted.

The portfolio we licensed from Bayer includes U.S. Patent 7,973,166, or the ‘166- patent, which covers a crystalline polymorph of entinostat which is referred to as crystalline polymorph- B, the crystalline polymorph used in the clinical development of entinostat. Many compounds can exist in different crystalline forms. A compound which in the solid state may exhibit multiple different crystalline forms is called polymorphic, and each crystalline form of the same chemical compound is termed a polymorph. A new crystalline form of a compound may arise, for example, due to a change in the chemical process or the introduction of an impurity. Such new crystalline forms may be patented. By comparison, the U.S. Patent RE39,754, which expired in September 2017, covers the chemical entity of entinostat and any crystalline or non-crystalline form of entinostat. On March 7, 2014, our licensor Bayer applied for reissue of the ‘166 patent. The reissue application sought to add three additional inventors to the ‘166 patent. The reissue was granted as RE45,499 on April 28, 2015, at which time the original ‘166 patent was surrendered. The reissue patent has the same force and effect as the original ‘166 patent and the same August 2029 expiration date.

Of the unexpired foreign-granted patents we licensed from Bayer, there are at least 35 granted foreign counterparts of the ‘166 patent (now RE45,499) that cover crystalline polymorph B, including the European patent and Eurasian patent. The granted European patent comprises 37 national countries that have all been validated, and the granted Eurasian patent comprises nine countries that have all been validated. Likewise, there are 2 pending foreign counterparts of the ‘166 crystalline polymorph B patent. Other patents and patent applications in the licensed Bayer portfolio are expired and covered methods of treatment by administration of entinostat.

Patent Term

The term of individual patents depends upon the legal term of the patents in the countries in which they are obtained. In most countries in which we file, the patent term is 20 years from the date of filing the earliest non-provisional application or PCT application.

In the United States, a patent’s term may be lengthened by patent term adjustment, which compensates a patentee for administrative delays by the U.S. Patent and Trademark Office, or USPTO in granting a patent, or may

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be shortened if a patent is terminally disclaimed over an earlier-filed patent. The term of a patent that covers an approved drug may also be eligible for patent term extension, which permits patent term restoration as compensation for the patent term lost during the development and regulatory review process. To obtain a patent extension in the United States, the term of the relevant patent must not have expired before the extension application, the patent cannot have been extended previously under this law, an application for extension must be submitted, the product must be subject to regulatory review prior to its commercialization, and the permission for the commercial marketing or use of the product after such regulatory review period is the first permitted commercial marketing or use of the product. If our future products contain active ingredients which have not been previously approved, we may be eligible for a patent term extension in the United States. In the United States, we are seeking for axatilimab and revumenib extension of patent terms under the Drug Price Competition and Patent Term Restoration Act of 1984, which permits a patent term extension of up to five years beyond the expiration of the patent for patent claims covering a new chemical entity. If patent extensions are available to us outside of the United States, we would expect to file for a patent term extension in applicable jurisdictions.

Confidential Information and Inventions Assignment Agreements

We require our employees and consultants to execute confidentiality agreements upon the commencement of employment, consulting or collaborative relationships with us. These agreements provide that all confidential information developed or made known during the course of the relationship with us be kept confidential and not disclosed to third parties except in specific circumstances.

In the case of employees, the agreements provide that all inventions resulting from work performed for us, utilizing our property or relating to our business and conceived or completed by the individual during employment shall be our exclusive property to the extent permitted by applicable law. Our consulting and service agreements also provide for assignment to us of any intellectual property resulting from services performed for us.

Government Regulation and Product Approval

United States Government Regulation

In the United States, the FDA regulates drugs and biologics under the Federal Food, Drug, and Cosmetic Act the Public Health Service Act, and related regulations. Drugs and biologics are also subject to other federal, state and local statutes and regulations. The FDA and comparable regulatory agencies in state and local jurisdictions impose substantial requirements upon, among other things, the testing, development, manufacture, quality control, safety, purity, potency, labeling, storage, distribution, record keeping and reporting, approval, import and export, advertising and promotion, and postmarket surveillance of drugs and biologics.

Biopharmaceutical Product Development Process

The process required by the FDA before biopharmaceutical products may be marketed in the United States generally involves the following:

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completion of extensive preclinical laboratory tests and animal studies in accordance with applicable regulations, including the FDA’s good laboratory practice, or GLP regulations;

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submission of an Investigational New Drug, or IND, application which must become effective before clinical trials may begin;

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performance of adequate and well-controlled human clinical trials in accordance with applicable regulations, including the FDA’s current good clinical practice, or cGCP, regulations to establish the safety and efficacy of the proposed drug for its intended use or uses;

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submission to the FDA of a New Drug Application, or NDA, for a new drug product or a Biologics License Application, or BLA, for biologics;

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a determination by the FDA within 60 days of its receipt of an NDA or BLA to accept the application for filing and review;

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satisfactory completion of an FDA inspection of the manufacturing facility or facilities where the drug or biologic is produced to assess compliance with the FDA’s current Good Manufacturing Practices, or cGMP, regulations to assure that the facilities, methods and controls are adequate to preserve the product’s identity, strength, quality and purity;

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potential FDA audit of the preclinical and/or clinical trial sites that generated the data in support of an NDA or BLA; and

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FDA review and approval of an NDA or BLA prior to any commercial marketing or sale of the biopharmaceutical product in the United States.

Before testing any compounds with potential therapeutic value in humans, the product candidate enters the preclinical testing stage. Preclinical tests include laboratory evaluations of product chemistry and formulation, as well as animal studies to assess the potential safety, toxicity profile and activity of the product candidate. The conduct of the preclinical tests must comply with federal regulations and requirements including GLPs.

Prior to commencing the first clinical trial in humans, an IND must be submitted to the FDA, and the IND must become effective. A sponsor must submit preclinical testing results to the FDA as part of the IND and the FDA must evaluate whether there is an adequate basis for testing the drug in humans. The IND automatically becomes effective 30 days after receipt by the FDA unless the FDA within the 30-day time period raises concerns or questions about the submitted data or the conduct of the proposed clinical trial and places the IND on clinical hold. In such case, the IND application sponsor must resolve any outstanding concerns with the FDA before the clinical trial may begin. A separate submission to the existing IND application must be made for each successive clinical trial to be conducted during product development. Further, an independent Institutional Review Board, or IRB, for each site proposing to conduct the clinical trial must review and approve the protocol and informed consent for any clinical trial before it commences at that site. Informed consent must also be obtained from each study subject. Regulatory authorities, an IRB, a data safety monitoring board or the trial sponsor may suspend or terminate a clinical trial at any time on various grounds, including a finding that the participants are being exposed to an unacceptable health risk.

Human clinical trials are typically conducted in three sequential phases that may overlap:

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Phase 1—The drug is initially given to healthy human subjects or patients and tested for safety, dosage tolerance, absorption, metabolism, distribution and excretion, the side effects associated with increasing doses, and if possible, to gain early evidence on effectiveness.

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Phase 2—The drug is evaluated in a limited patient population to identify possible adverse effects and safety risks, to preliminarily evaluate the efficacy of the product for specific targeted diseases or conditions and to determine dosage tolerance, optimal dosage and dosing schedule.

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Phase 3—Clinical trials are undertaken to further evaluate dosage, clinical efficacy and safety at geographically dispersed clinical trial sites. These clinical trials are intended to establish the overall benefit-risk ratio of the product and to provide an adequate basis for product approval by the FDA.

Post-approval studies, or Phase 4 clinical trials, may be conducted after initial marketing approval. These studies may be required by the FDA as a condition of approval and are used to gain additional experience from the treatment of patients in the intended therapeutic indication. The FDA also has express statutory authority to require post-market clinical studies to address safety issues.

Some clinical trials are overseen by an independent group of qualified experts organized by the clinical trial sponsor, known as a data monitoring board or committee. This group provides recommendations for whether or not a trial may move forward at designated checkpoints based on access to certain data from the study. A sponsor may also suspend or terminate a clinical trial based on evolving business objectives and/or competitive climate.

Concurrent with clinical trials, companies usually complete additional animal studies and must also develop additional information about the chemistry and physical characteristics of the product candidate as well as finalize a process for manufacturing the product in commercial quantities in accordance with cGMP requirements. The manufacturing process must be capable of consistently producing quality batches of the drug candidate and, among other things, must include developed methods for testing the identity, strength, quality and purity of the finished product. Additionally, appropriate packaging must be selected and tested and stability studies must be conducted to demonstrate that the product candidate does not undergo unacceptable deterioration over its shelf life.

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FDA Review and Approval Processes

In order to obtain approval to market a biopharmaceutical product in the United States, a marketing application must be submitted to the FDA that provides data establishing to the FDA’s satisfaction the safety and effectiveness of the investigational drug for the proposed indication. Each NDA or BLA submission requires a substantial user fee payment unless a waiver or exemption applies. The application includes all relevant data available from pertinent nonclinical studies and clinical trials, including negative or ambiguous results as well as positive findings, together with detailed information relating to the product’s chemistry, manufacturing, controls and proposed labeling, among other things. Data can come from company-sponsored clinical trials intended to test the safety and effectiveness of a use of a product, or from a number of alternative sources, including studies initiated by investigators.

The FDA will initially review an NDA or BLA for completeness before it accepts it for filing. The FDA has 60 days from its receipt of an application to determine whether the application will be accepted for filing based on the agency’s threshold determination that the application is sufficiently complete to permit substantive review. If it is not, the FDA may refuse to file the application and request additional information, in which case the application must be resubmitted with the supplemental information, and review of the application is delayed. After an NDA or BLA submission is accepted for filing, the FDA reviews the application to determine, among other things, whether the proposed product is safe and effective for its intended use, and whether the product is being manufactured in accordance with cGMP to assure and preserve the product’s identity, strength, quality and purity. The FDA may refer applications for novel drug products or drug products that present difficult questions of safety or efficacy to an advisory committee, typically a panel that includes clinicians and other experts, for review, evaluation and a recommendation as to whether the application should be approved and, if so, under what conditions. The FDA is not bound by the recommendations of an advisory committee, but it considers such recommendations carefully when making decisions.

Upon the filing of an NDA or BLA, the FDA may grant a priority review designation to a product, which sets the target date for FDA action on the application at 6 months, rather than the standard 10 months. Priority review is given for drug that treats a serious condition and, if approved, would provide a significant improvement in safety or effectiveness. Priority review designation does not change the scientific or medical standard for approval or the quality of evidence necessary to support approval.

Before approving an NDA or BLA, the FDA will inspect the facilities at which the product is manufactured. The FDA will not approve the product unless it determines that the manufacturing processes and facilities are in compliance with cGMP requirements and adequate to assure consistent production of the product within required specifications. Additionally, before approving an NDA or BLA, the FDA may inspect one or more clinical sites to assure compliance with GCP.

After the FDA completes its initial review of an NDA or BLA, it will communicate to the sponsor that the product is approved, or it will issue a complete response letter to communicate that the application will not be approved in its current form and inform the sponsor of changes that must be made or additional clinical, nonclinical or manufacturing data that must be received before the application can be approved.

Even if a product candidate receives regulatory approval, the approval may be limited to specific disease states, patient populations and dosages, or might contain significant limitations on use in the form of warnings, precautions or contraindications, or in the form of onerous risk management plans, restrictions on distribution, or post-marketing study requirements. For example, the FDA may require Phase 4 testing, which involves clinical trials designed to further assess a drug’s safety and effectiveness and may require testing and surveillance programs to monitor the safety of approved products that have been commercialized. The FDA may also determine that a risk evaluation and mitigation strategy, or REMS, is necessary to assure the safe use of the drug. If the FDA concludes a REMS is needed, the sponsor of an NDA must submit a proposed REMS, and the FDA will not approve an NDA without an approved REMS, if required.

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Expedited Review Programs

Among other programs, the FDA may expedite the review of a product candidate designated as a breakthrough therapy, which is intended, alone or in combination with one or more other drugs, to treat a serious or life-threatening disease or condition and preliminary clinical evidence indicates that the drug may demonstrate substantial improvement over existing therapies on one or more clinically significant endpoints, such as substantial treatment effects observed early in clinical development. A sponsor may request the FDA to designate a drug as a breakthrough therapy at the time of, or any time after, the submission of an IND application for the drug. If the FDA designates a drug as a breakthrough therapy, it may take actions appropriate to expedite the development and review of the application, which may include holding meetings with the sponsor and the review team throughout the development of the drug; providing timely advice to, and interactive communication with, the sponsor regarding the development of the drug to ensure that the development program to gather the nonclinical and clinical data necessary for approval is as efficient as practicable; involving senior managers and experienced review staff, as appropriate, in a collaborative, cross-disciplinary review; assigning a cross-disciplinary project lead for the FDA review team to facilitate an efficient review of the development program and to serve as a scientific liaison between the review team and the sponsor; and taking steps to ensure that the design of the clinical trials is as efficient as practicable, when scientifically appropriate, such as by minimizing the number of patients exposed to a potentially less efficacious treatment. The FDA may rescind a breakthrough therapy designation in the future if further clinical development later shows that the criteria for designation are no longer met.

Breakthrough therapy designation does not change the standards for approval but may expedite the development or review process.

Post-Approval Requirements

If and when approved, any products manufactured or distributed by us or on our behalf will be subject to continuing regulation by the FDA, including requirements for record-keeping, reporting of adverse experiences and submitting annual reports.

Biopharmaceutical manufacturers are required to register their facilities with the FDA and certain state agencies, and are subject to periodic unannounced inspections by the FDA and certain state agencies for compliance with cGMPs, which impose certain quality processes, manufacturing controls and documentation requirements upon us and our third-party manufacturers in order to ensure that the product is safe, has the identity and strength, and meets the quality and purity characteristics that it purports to have. The FDA and certain states also impose requirements on manufacturers and distributors to establish the pedigree of product in the chain of distribution, including technology capable of tracking and tracing product as it moves through the distribution chain. We cannot be certain that we or our present or future suppliers will be able to comply with the cGMP and other FDA regulatory requirements. If our present or future suppliers are not able to comply with these requirements, the FDA may halt our clinical trials, fail to approve any application, shut down manufacturing operations or withdraw approval of an application, or we may recall the product from distribution. Noncompliance with cGMP or other requirements can result in issuance of warning letters, civil and criminal penalties, seizures and injunctive action.

The FDA closely regulates the labeling, marketing and promotion of drugs and biologics. While doctors are free to prescribe any drug approved by the FDA for any use based on the doctor’s independent medical judgment, a company can only make claims relating to safety and efficacy of a drug that are consistent with FDA approval, and a company is allowed to actively market a drug only for the particular use and treatment approved by the FDA. In addition, any claims we make for our products in advertising or promotion must be appropriately balanced with important safety information and otherwise be adequately substantiated. Failure to comply with these requirements can result in adverse publicity, warning letters, corrective advertising, injunctions and potential civil and criminal penalties. Government regulators recently have increased their scrutiny of the promotion and marketing of drugs.

Coverage and Reimbursement

In both domestic and foreign markets, sales of Revuforj, Niktimvo and any other products for which we may receive regulatory approval will depend in part upon the availability of formulary coverage and adequate reimbursement to healthcare providers from third-party payors. Such third-party payors include government health

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programs, such as Medicare and Medicaid, as well as managed care organizations, private health insurers and other organizations. Coverage decisions may depend upon clinical and economic standards that disfavor new drug products when more established or lower cost therapeutic alternatives are available. Assuming coverage is granted, the reimbursement rates paid for covered products might not be adequate. Even if favorable coverage status and adequate reimbursement rates are attained, less favorable coverage policies and reimbursement rates may be implemented in the future. The marketability of Revuforj, Niktimvo and any other products for which we may receive regulatory approval for commercial sale may suffer if the government and other third-party payors fail to provide coverage and adequate reimbursement to allow us to sell such products on a competitive and profitable basis. For example, under these circumstances, physicians may limit how much or under what circumstances they will prescribe or administer such products, and patients may decline to purchase them. This, in turn, could affect our ability to successfully commercialize our products and impact our profitability, results of operations, financial condition, and future success.

In the United States, the European Union and other potentially significant markets for our products and product candidates, government authorities and third-party payors are increasingly attempting to limit or regulate the price of medical products and services, particularly for new and innovative products and therapies. For example, the U.S. Department of Health and Human Services, or HHS, imposes rebates on many Medicare Part B and Medicare Part D products to penalize price increases that outpace inflation on an annual basis. HHS also has been empowered to negotiate the price of certain single-source drugs that have been on the market for at least seven years and single-course biologics that have been on the market for at least 11 years covered under Medicare as part of the Medicare Drug Price Negotiation Program. Each year up to 20 products will be selected by HHS for the Medicare Drug Price Negotiation Program. Products subject to the Medicare Drug Price Negotiation Program are expected to experience a significant reduction in reimbursement from the Medicare program on a per unit basis. Adoption of price controls and cost-containment measures, and adoption of more restrictive policies in jurisdictions with existing controls and measures, could further limit a company’s revenue generated from the sale of any approved products. Such pressure, along with the increased emphasis on managed healthcare in the United States and on country and regional pricing and reimbursement controls in the European Union, will likely put additional downward pressure on product pricing, reimbursement and usage, which may adversely affect our future product sales and results of operations. These pressures can arise from rules and practices of managed care groups, judicial decisions, governmental laws and regulations related to government healthcare programs, healthcare reform, and pharmaceutical coverage and reimbursement policies.

The market for Revuforj, Niktimvo and any other product candidates for which we may receive regulatory approval will depend significantly on the degree to which these products are listed on third-party payors’ drug formularies or lists of medications for which third-party payors provide coverage and reimbursement to the extent products for which we may receive regulatory approval are covered under a pharmacy benefit or are otherwise subject to a formulary. The industry competition to be included on such formularies often leads to downward pricing pressures on pharmaceutical companies. Also, third-party payors may refuse to include a particular branded drug on their formularies or otherwise restrict patient access to a branded drug when a less costly generic equivalent or other alternative is available. In addition, because each third-party payor individually approves coverage and reimbursement levels, obtaining coverage and adequate reimbursement is a time-consuming and costly process. Further, one payor’s determination to provide coverage for a drug product does not assure that other payors will also provide coverage for the drug product. We may be required to provide scientific and clinical support for the use of any product to each third-party payor separately with no assurance that approval would be obtained, and we may need to conduct expensive pharmacoeconomic studies in order to demonstrate the cost-effectiveness of our products. We cannot be certain that Revuforj, Niktimvo and any other product candidates for which we may receive regulatory approval will be considered cost-effective. This process could delay the market acceptance of such products and could have a negative effect on our future revenue and operating results.

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Federal and State Fraud and Abuse and Data Privacy and Security Laws and Regulations

In addition to FDA restrictions on marketing of pharmaceutical products, federal and state laws restrict business practices in the pharmaceutical industry. These laws include anti-kickback and false claims laws and regulations as well as data privacy and security laws and regulations. The laws that will affect our operations include, but are not limited to:

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the federal Anti-Kickback Statute, which prohibits, among other things, persons or entities from knowingly and willfully soliciting, receiving, offering or paying any remuneration (including any kickback, bribe or rebate), directly or indirectly, overtly or covertly, in cash or in kind, in return for the purchase, recommendation, leasing or furnishing of an item or service reimbursable under a federal healthcare program, such as the Medicare and Medicaid programs. This statute has been interpreted to apply to arrangements between pharmaceutical manufacturers on the one hand, and prescribers, purchasers and formulary managers on the other. The Patient Protection and Affordable Care Act, as amended by the Health Care and Education Reconciliation Act, collectively, the Affordable Care Act, amended the intent requirement of the federal Anti-Kickback Statute so that a person or entity no longer needs to have actual knowledge of this statute or specific intent to violate it in order to have committed a violation;

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federal civil and criminal false claims laws, including, without limitation, the False Claims Act, or FCA, and civil monetary penalty laws which prohibit, among other things, individuals or entities from knowingly presenting, or causing to be presented, claims for payment or approval from Medicare, Medicaid or other government payors that are false or fraudulent or making a false statement to avoid, decrease or conceal an obligation to pay money to the federal government. The Affordable Care Act provides, and recent government cases against pharmaceutical manufacturers support, the view that federal Anti-Kickback Statute violations and certain marketing practices, including off-label promotion, may implicate the FCA;

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the federal Health Insurance Portability and Accountability Act of 1996, or HIPAA, which created additional federal criminal statutes that, among other things, prohibit a person from knowingly and willfully executing a scheme or making false or fraudulent statements to defraud any healthcare benefit program, regardless of the payor (e.g., public or private);

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HIPAA, as amended by the Health Information Technology for Economic and Clinical Health Act, or HITECH, and their implementing regulations, which imposes certain requirements relating to the privacy, security and transmission of individually identifiable health information without appropriate authorization by entities subject to the rule, such as health plans, healthcare clearinghouses and certain healthcare providers, known as covered entities, and their respective business associates, individuals or entities that perform certain services on behalf of a covered entity that involves the use or disclosure of individually identifiable health information, and their covered subcontractors;

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the federal Physician Payments Sunshine Act, which requires certain manufacturers of drugs, devices, biologics and medical supplies for which payment is available under Medicare, Medicaid or the Children’s Health Insurance Program, with specific exceptions, to report annually to the Centers for Medicare & Medicaid Services, or CMS, information related to: (i) payments or other “transfers of value” made to physicians (defined to include doctors, dentists, optometrists, podiatrists and chiropractors), other healthcare professionals (such as physician assistants and nurse practitioners), and teaching hospitals; and (ii) ownership and investment interests held by physicians and their immediate family members; and

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state law equivalents of each of the above federal laws, state laws that require manufacturers to report information related to payments and other transfers of value to physicians and other healthcare providers or marketing expenditures, state laws that require pharmaceutical companies to comply with the pharmaceutical industry’s voluntary compliance guidelines and the relevant compliance guidance promulgated by the federal government or to adopt compliance programs as prescribed by state laws and regulations, or that otherwise restrict payments that may be made to healthcare providers, state laws that require manufactures to report pricing information regarding certain drugs, state and local laws that require the registration of pharmaceutical sales representatives, and state laws that govern the privacy and security of health information, which differ from each other in significant ways and often are not preempted by HIPAA, thus complicating compliance efforts.

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We may also be subject to federal and state laws that govern the privacy and security of other personal data, including federal and state consumer protection laws, state data security laws, and data breach notification laws. A data breach affecting sensitive personal data, including health information, could result in significant legal and financial exposure and reputational damages.

Because of the breadth of these laws and the narrowness of available statutory and regulatory exemptions, it is possible that some of our business activities could be subject to challenge, investigation or legal action under one or more of such laws. If our operations are found to be in violation of any of the federal and state laws described above or any other governmental regulations that apply to us, we may be subject to significant civil, criminal, and administrative penalties, including, without limitation, damages, fines, imprisonment, disgorgement, exclusion from participation in government healthcare programs, additional reporting requirements and oversight if we become subject to a corporate integrity agreement or similar agreement to resolve allegations of non-compliance with these laws, and the curtailment or restructuring of our operations.

To the extent that any of our product candidates receive approval and are sold in a foreign country, we may be subject to similar foreign laws and regulations, which may include, for instance, applicable post-marketing requirements, including safety surveillance, anti-fraud and abuse laws, international data protection laws (including the General Data Protection Directive ((EU) 2016/679) on the protection of individuals with regard to the processing of personal data and on the free movement of such data as well as EU member state implementing legislation), and implementation of corporate compliance programs and reporting of payments or transfers of value to healthcare professionals.

Healthcare Reform

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 Revuforj, Niktimvo, and any other product candidates for which we obtain marketing approval. Among policy makers and payors in the United States and elsewhere, there is significant interest in promoting changes in healthcare systems with the stated goals of containing healthcare costs, improving quality and expanding access. In the United States, the pharmaceutical industry has been a particular focus of these efforts and has been significantly affected by major legislative initiatives. For example, in March 2010, the Affordable Care Act was passed, which has changed health care financing by both governmental and private insurers and significantly affected the U.S. pharmaceutical industry.

Since its enactment, there have been executive, judicial and Congressional challenges and amendments to certain aspects of the Affordable Care Act. For example, on July 4, 2025, the One Big Beautiful Bill Act, or the OBBBA, was signed into law, which narrowed access to Affordable Care Act marketplace exchange enrollment and declined to extend the Affordable Care Act’s enhanced advanced premium tax credits that expired at the end of 2025, which, among other provisions in the law, are anticipated to reduce the number of Americans with health insurance. The OBBBA also is expected to reduce Medicaid spending and enrollment by implementing work requirements for some beneficiaries, capping state-directed payments, reducing federal funding, and limiting provider taxes used to fund the program. Congress is considering proposed legislation intended to further reduce healthcare costs with alternatives to replace the expired Affordable Care Act subsidies. We expect that additional United States federal healthcare reform measures will be adopted in the future, any of which could limit the amounts that the federal government will pay for healthcare products and services, which could result in reduced demand for our products or additional pricing pressures.

There has been increasing legislative and enforcement interest in the United States with respect to specialty drug pricing practices. Additionally, the current administration is pursuing policies to reduce regulations and expenditures across government including at HHS, the FDA, CMS and related agencies. These actions, presently directed by executive orders or memoranda from the Office of Management and Budget, may propose policy changes that create additional uncertainty for our business. For example, the current administration has announced agreements with several pharmaceutical companies that require the drug manufacturers to offer, through a direct-to-consumer platform, U.S. patients and Medicaid programs prescription drug Most-Favored Nation pricing equal to or lower than those paid in other developed nations, with additional mandates for direct-to-patient discounts and repatriation of foreign revenues. Other recent actions, for example, include (1) directing agencies to reduce agency

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workforce and cut programs; (2) directing HHS and other agencies to lower prescription drug costs through a variety of initiatives, including by improving upon the Medicare Drug Price Negotiation Program and establishing Most-Favored-Nation pricing for pharmaceutical products; (3) imposing tariffs on imported pharmaceutical products; and (4) as part of the Make America Healthy Again Commission’s Strategy Report released in September 2025, working across government agencies to increase enforcement on direct-to-consumer pharmaceutical advertising. Additionally, the current administration recently called on Congress to enact “The Great Healthcare Plan,” to codify and expand Most-Favored Nation pricing, lower government subsidies to private insurance companies, increase healthcare price transparency, expand pharmaceutical drugs available for over-the-counter purchase, and enact restrictions on pharmacy benefit manager payment methodologies, among other things. These actions and policies may significantly reduce drug prices in the United States, potentially impacting manufacturers’ global pricing strategies and profitability, while increasing their operational costs and compliance risks. Additionally, in its June 2024 decision in Loper Bright Enterprises v. Raimondo, or Loper Bright, the U.S. Supreme Court greatly reduced judicial deference to regulatory agencies, which could increase successful legal challenges to federal regulations affecting our operations. Congress may introduce and ultimately pass health care related legislation that could impact the drug approval process and make changes to the Medicare Drug Price Negotiation Program.

We expect that additional state, federal, and foreign healthcare reform measures will be adopted in the future. The full impact on our business of these health reform measures and other new laws is uncertain but may result in additional reductions in Medicare and other healthcare funding. Nor is it clear whether other legislative changes will be adopted, if any, or how such changes would affect our business, including the demand for our products.

Regulations Outside of the United States

In addition to regulations in the United States, we will be subject to a variety of foreign regulations governing clinical trials and commercial sales and distribution of our product candidates to the extent we choose to sell any products outside of the United States. Whether or not we obtain FDA approval for a product, we must obtain approval of a product by the comparable regulatory authorities of foreign countries before we can commence clinical trials or marketing of the product in those countries. The approval process varies from country to country and the time may be longer or shorter than that required for FDA approval. The requirements governing the conduct of clinical trials, product licensing, pricing and reimbursement vary greatly from country to country. As in the United States, post-approval regulatory requirements, such as those regarding product manufacture, marketing, or distribution would apply to any product that is approved outside the United States.

Other Regulations

We are also subject to numerous federal, state and local laws relating to such matters as safe working conditions, manufacturing practices, environmental protection, fire hazard control, and disposal of hazardous or potentially hazardous substances. We may incur significant costs to comply with such laws and regulations now or in the future.

Employees and Human Capital Resources

As of December 31, 2025, we had 298 full-time employees of which 144 were primarily engaged in research and development activities and 65 with M.D., Ph.D., or PharmD degree. As of February 16, 2026, we had 277 full-time employees. Of the full-time employees, 128 were primarily engaged in research and development activities and 56 have an M.D., Ph.D., or PharmD degree. None of our employees are represented by labor unions or covered by collective bargaining agreements. We consider our relationship with our employees to be good. To allow us flexibility in meeting varying workflow demands, we also engage consultants and temporary workers when needed.

Our human capital resources objectives include, as applicable, identifying, recruiting, retaining, incentivizing and integrating our existing and additional employees. All employees must adhere to a code of business conduct and ethics and our employee handbook, which combined, define standards for appropriate behavior and are annually trained to help prevent, identify, report, and stop any type of discrimination and harassment.

We consider a number of measures and objectives in managing our human capital assets, including, among others, employee engagement, development, and training, talent acquisition and retention, employee safety and wellness, diversity and inclusion, and compensation and pay equity. We provide our employees with salaries and

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bonuses intended to be competitive for our industry, opportunities for equity ownership, development programs that enable continued learning and growth and a robust benefits package to promote well-being across all aspects of their lives, including health care, retirement planning and paid time off. The principal purposes of our equity incentive plans are to attract, retain and motivate selected employees and directors through the granting of equity-based compensation awards and cash-based compensation awards, in order to increase stockholder value and the success of our company by motivating such individuals to perform to the best of their abilities and achieve our objectives.

In addition, we have conducted employee surveys to gauge employee engagement and identify areas of future focus for our human capital practices and benefits offerings.

Corporate and Other Information

We were incorporated in Delaware in 2005. In 2021, we established a wholly owned subsidiary in the Netherlands. There have been no material activities for these entities to date. We currently operate in one segment.

Our principal office is located in New York, New York, where we lease approximately 12,000 square feet of office space pursuant to a lease that expires in August 2028. In February 2025, following the expiration of our lease, we closed our office in Waltham, Massachusetts and made New York our principal office. We believe our facilities are adequate to meet our current needs, although we may seek to negotiate new leases or evaluate additional or alternate space for our operations. We believe appropriate alternative space will be readily available on commercially reasonable terms.

We file electronically with the Securities and Exchange Commission, or SEC, our annual reports on Form 10-K, quarterly reports on Form 10-Q, current reports on Form 8-K, and amendments to those reports filed or furnished pursuant to Section 13(a) or 15(d) of the Exchange Act. We make available on our website at www.syndax.com, under “Investors,” free of charge, copies of these reports as soon as reasonably practicable after filing or furnishing these reports with the SEC.