– Abstracts highlight strong revumenib activity across the acute leukemia treatment continuum and multiple genetic subtypes – – New real-world data show compelling outcomes and favorable tolerability with revumenib monotherapy and combination use – – Two abstracts highlight encouraging results with revumenib in the post-transplant setting – – Frontline and R/R revumenib combination data show deep responses, robust transplant rates, and favorable tolerability – – Encouraging activity observed with revumenib in R/R NUP98r acute leukemia – NEW YORK, May 12, 2026 (GLOBE NEWSWIRE) -- Syndax Pharmaceuticals (Nasdaq: SNDX), a commercial-stage biopharmaceutical company advancing innovative cancer therapies, today highlighted the release of 12 Revuforj® (revumenib) abstracts on the European Hematology Association (EHA) website in advance of the EHA 2026 Congress, taking place June 11-14, 2026, in Stockholm, Sweden. “The breadth of data accepted for presentation at EHA underscores the strength of revumenib’s clinical profile, with activity observed across the acute leukemia treatment continuum in KMT2Ar, NPM1m, and NUP98r acute leukemias,” said Nick Botwood, MBBS, Head of Research & Development and Chief Medical Officer at Syndax. “Given the need for therapies that can reduce the risk of relapse after stem cell transplantation, we are excited for the presentation of new data from the post-transplant setting showing favorable outcomes with revumenib compared to historical data. We also look forward to sharing additional frontline and R/R combination data showing high rates of MRD negativity, transplant, and favorable tolerability, supporting physician decision making and our ongoing pivotal trials.” Dr. Botwood continued, “Collectively, these new data highlight our scientific leadership in menin inhibition and bolster our confidence that we are positioned to transform the treatment paradigm for 50% or more of patients with AML.” Key revumenib data accepted for presentation at EHA 2026: Findings from the ROAR study, a multicenter real-world study of revumenib in relapsed/refractory (R/R) acute leukemia.Updated frontline data from the Phase 1 trial of revumenib in combination with intensive chemotherapy in NPM1 mutated (NPM1m), KMT2A-rearranged (KMT2Ar), or NUP98-rearranged (NUP98r) acute myeloid leukemia (AML).Outcomes among adults and children with KMT2Ar, NPM1m, and NUP98r acute leukemia who received revumenib as maintenance following hematopoietic stem cell transplantation (HSCT).Updated R/R data from the SAVE trial of revumenib in combination with venetoclax and decitabine/cedazuridine in NPM1m, KMT2Ar, and NUP98r acute leukemia.Results in patients with R/R NUP98r acute leukemia treated with revumenib in AUGMENT-101 or via an expanded access program. The accepted abstracts listed below are now available online on the EHA conference website. Copies of the poster presentations will be made available in the ‘Publications & Meetings Presentations’ section of the Syndax website after the embargo lifts. Full list of revumenib abstracts accepted for EHA 2026 (all times in CEST): Abstract TitlesPresentation DetailsReal-world evidenceRevumenib in the real world: interim findings from the ROAR study in relapsed/refractory acute leukemiaAbstract Code: PF542Poster Session 1Friday, June 12, 6:45-7:45 pmFrontlineRevumenib + intensive chemotherapy for newly diagnosed acute myeloid leukemia harboring genetic alterations in KMT2A, NPM1, or NUP98: updated phase 1 results from SNDX-5613-0708Abstract Code: PF489Poster Session 1Friday, June 12, 6:45-7:45 pmPost-HSCT maintenanceRevumenib as maintenance for AML following allogeneic stem cell transplantationPoster number: PS1629Poster Session 2Saturday, June 13, 6:45-7:45 pmEncore of data accepted for oral presentation at ASCO 2026Revumenib therapy post hematopoietic stem cell transplant for patients with relapsed/refractory KMT2Ar, NPM1m, and NUP98r acute myeloid leukemia: post hoc analysis of outcomes from AUGMENT-101Abstract Code: PS1631Poster Session 2Saturday, June 13, 6:45-7:45 pmRelapsed/refractoryPhase 1/2 study of the all-oral combination of revumenib (SNDX-5613) with decitabine/cedazuridine (ASTX727) and venetoclax (SAVE) in relapsed/refractory AMLAbstract Code: PF495Poster Session 1Friday, June 12, 6:45-7:45 pmLong-term follow-up of pediatric/young adult patients with relapsed/refractory KMT2Ar acute leukemia treated with revumenib in AUGMENT-101Abstract Code: PF508Poster Session 1Friday, June 12, 6:45-7:45 pmEfficacy of revumenib in acute myeloid leukemia harboring NPM1-mutated co-mutations: post hoc analysis of AUGMENT-101Abstract Code: PF514Poster Session 1Friday, June 12, 6:45-7:45 pmPharmacokinetic assessment of revumenib in patients with relapsed/refractory acute leukemias harboring a KMT2A rearrangement or NPM1 mutation: Impact of food and concomitant medicationsAbstract Code: PF564Poster Session 1Friday, June 12, 6:45-7:45 pmEncore of data accepted for poster presentation at ASCO 2026Clinical activity of revumenib in patients with relapsed/refractory NUP98-rearranged acute leukemiasAbstract Code: PS1607Poster Session 2Saturday, June 13, 6:45-7:45 pmTrials in progressA phase 3 study of revumenib in combination with intensive chemotherapy in patients with newly diagnosed NPM1-mutated acute myeloid leukemia (REVEAL-ND NPM1): Trial in progressAbstract Code: PB2821Publication onlyRevumenib + venetoclax/azacitidine in adults with newly diagnosed NPM1m or KMT2Ar acute leukemia ineligible for intensive chemotherapy (EVOLVE-2/HO177/AMLSG35-24/ACT-HOV-AML-002): Trial in progressAbstract Code: PB2796Publication onlyA phase 1/2 study of the menin inhibitor revumenib with the CELMod mezigdomide in relapsed/refractory KMT2A-rearanged, NPM1-mutant, and NUP98-rearranged acute leukemiasAbstract Code: PS1658Poster Session 2Saturday, June 13, 6:45-7:45 pm About Revuforj® (revumenib) Revuforj (revumenib) is an oral, first-in-class menin inhibitor that is FDA approved for the treatment of relapsed or refractory (R/R) acute leukemia with a lysine methyltransferase 2A gene (KMT2A) translocation as determined by an FDA-authorized test in adult and pediatric patients one year and older. Revuforj is also indicated for the treatment of R/R acute myeloid leukemia (AML) with a susceptible nucleophosmin 1 (NPM1) mutation in adult and pediatric patients one year and older who have no satisfactory alternative treatment options. Multiple trials of revumenib are ongoing or planned across the treatment landscape, including in combination with standard of care therapies in newly diagnosed patients with NPM1m or KMT2Ar AML. Revumenib was previously granted Orphan Drug Designation for the treatment of AML, ALL and acute leukemias of ambiguous lineage (ALAL) by the U.S. FDA and for the treatment of AML by the European Commission. The U.S. FDA also granted Fast Track designation to revumenib for the treatment of adult and pediatric patients with R/R acute leukemias harboring a KMT2A rearrangement or NPM1 mutation and Breakthrough Therapy Designation for the treatment of adult and pediatric patients with R/R acute leukemia harboring a KMT2A rearrangement. Revuforj (revumenib) IMPORTANT SAFETY INFORMATION WARNING: DIFFERENTIATION SYNDROME, QTc PROLONGATION, and TORSADES DE POINTES Differentiation syndrome, which can be fatal, has occurred with Revuforj. Signs and symptoms may include fever, dyspnea, hypoxia, pulmonary infiltrates, pleural or pericardial effusions, rapid weight gain or peripheral edema, hypotension, and renal dysfunction. If differentiation syndrome is suspected, immediately initiate corticosteroid therapy and hemodynamic monitoring until symptom resolution. QTc prolongation and Torsades de Pointes have occurred in patients receiving Revuforj. Correct hypokalemia and hypomagnesemia prior to and during treatment. Do not initiate Revuforj in patients with QTcF > 450 msec. If QTc interval prolongation occurs, interrupt, reduce, or permanently discontinue Revuforj. WARNINGS AND PRECAUTIONS Differentiation Syndrome: Revuforj can cause fatal or life-threatening differentiation syndrome (DS). Symptoms of DS, including those seen in patients treated with Revuforj, include fever, dyspnea, hypoxia, peripheral edema, pleuropericardial effusion, acute renal failure, rash, and/or hypotension. In clinical trials, DS occurred in 60 (25%) of 241 patients treated with Revuforj at the recommended dosage for relapsed or refractory acute leukemia. Among those with a KMT2A translocation, DS occurred in 33% of patients with acute myeloid leukemia (AML), 33% of patients with mixed-phenotype acute leukemia (MPAL), and 9% of patients with acute lymphoblastic leukemia (ALL); DS occurred in 18% of patients with NPM1m AML. DS was Grade 3 or 4 in 12% of patients and fatal in 2 patients. The median time to initial onset was 9 days (range 3-41 days). Some patients experienced more than 1 DS event. Treatment interruption was required for 7% of patients, and treatment was withdrawn for 1%. Reduce the white blood cell count to less than 25 Gi/L prior to starting Revuforj. If DS is suspected, immediately initiate treatment with systemic corticosteroids (e.g., dexamethasone 10 mg IV every 12 hours in adults or dexamethasone 0.25 mg/kg/dose IV every 12 hours in pediatric patients weighing less than 40 kg) for a minimum of 3 days and until resolution of signs and symptoms. Institute supportive measures and hemodynamic monitoring until improvement. Interrupt Revuforj if severe signs and/or symptoms persist for more than 48 hours after initiation of systemic corticosteroids, or earlier if life-threatening symptoms occur such as pulmonary symptoms requiring ventilator support. Restart steroids promptly if DS recurs after tapering corticosteroids. QTc Interval Prolongation and Torsades de Pointes: Revuforj can cause QT (QTc) interval prolongation and Torsades de Pointes. Of the 241 patients treated with Revuforj at the recommended dosage for relapsed or refractory acute leukemia in clinical trials, QTc interval prolongation was reported as an adverse reaction in 86 (36%) patients. QTc interval prolongation was Grade 3 in 15% and Grade 4 in 2%. The heart-rate corrected QT interval (using Fridericia’s method) (QTcF) was greater than 500 msec in 10%, and the increase from baseline QTcF was greater than 60 msec in 24%. Revuforj dose reduction was required for 7% due to QTc interval prolongation. QTc prolongation occurred in 21% of the 34 patients less than 17 years old, 35% of the 146 patients 17 years to less than 65 years old, and 46% of the 61 patients 65 years or older. One patient had a fatal outcome of cardiac arrest, and one patient had non-sustained Torsades de Pointes. Correct electrolyte abnormalities, including hypokalemia and hypomagnesemia, prior to and throughout treatment with Revuforj. Perform an electrocardiogram (ECG) prior to initiation of Revuforj, and do not initiate Revuforj in patients with QTcF >450 msec. Perform an ECG at least once weekly for the first 4 weeks and at least monthly thereafter. In patients with congenital long QTc syndrome, congestive heart failure, electrolyte abnormalities, or those who are taking medications known to prolong the QTc interval, more frequent ECG monitoring may be necessary. Concomitant use with drugs known to prolong the QTc interval may increase the risk of QTc interval prolongation. Interrupt Revuforj if QTcF increases >480 msec and <500 msec, and restart Revuforj at the same dose twice daily after the QTcF interval returns to ≤480 msecInterrupt Revuforj if QTcF increases >500 msec or by >60 msec from baseline, and restart Revuforj twice daily at the lower-dose level after the QTcF interval returns to ≤480 msecPermanently discontinue Revuforj in patients with ventricular arrhythmias and in those who develop QTc interval prolongation with signs or symptoms of life-threatening arrhythmia Embryo-Fetal Toxicity: Revuforj can cause fetal harm when administered to a pregnant woman. Advise pregnant women of the potential risk to a fetus. Advise females of reproductive potential and males with female partners of reproductive potential to use effective contraception during treatment with Revuforj and for 4 months after the last dose of Revuforj. ADVERSE REACTIONS Fatal adverse reactions occurred in 9 (4%) patients who received Revuforj, including 4 with sudden death, 2 with differentiation syndrome, 2 with hemorrhage, and 1 with cardiac arrest. Serious adverse reactions were reported in 184 (76%) patients. The most frequent serious adverse reactions (≥10%) were infection (29%), febrile neutropenia (20%), bacterial infection (15%), differentiation syndrome (13%), and hemorrhage (11%). The most common adverse reactions (≥20%) including laboratory abnormalities, were phosphate increased (51%), hemorrhage (48%), nausea (48%), infection without identified pathogen (46%), aspartate aminotransferase increased (44%), alanine aminotransferase increased (40%), creatinine increased (38%), musculoskeletal pain (37%), febrile neutropenia (37%), electrocardiogram QT prolonged (36%), potassium decreased (34%), parathyroid hormone intact increased (34%), alkaline phosphatase increased (33%), diarrhea (29%), bacterial infection (27%), triglycerides increased (27%), phosphate decreased (25%), differentiation syndrome (25%), fatigue (24%), edema (24%), viral infection (23%), decreased appetite (20%), and constipation (20%). DRUG INTERACTIONS Drug interactions can occur when Revuforj is concomitantly used with: Strong CYP3A4 inhibitors: reduce Revuforj doseStrong or moderate CYP3A4 inducers: avoid concomitant use with RevuforjQTc-prolonging drugs: avoid concomitant use with Revuforj. If concomitant use is unavoidable, obtain ECGs when initiating, during concomitant use, and as clinically indicated. Withhold Revuforj if the QTc interval is >480 msec. Restart Revuforj after the QTc interval returns to ≤480 msec SPECIFIC POPULATIONS Lactation: advise lactating women not to breastfeed during treatment with Revuforj and for 1 week after the last dose. Pregnancy and testing: Revuforj can cause fetal harm when administered to a pregnant woman. Verify pregnancy status in females of reproductive potential within 7 days prior to initiating Revuforj. Infertility: based on findings in animals, Revuforj may impair fertility. The effects on fertility were reversible. Pediatric: monitor bone growth and development in pediatric patients. Geriatric: no overall differences were observed in the effectiveness of Revuforj between patients who were 65 years and older, and younger patients. Compared to younger patients, the incidences of QTc prolongation and edema were higher in patients 65 years and older. To report SUSPECTED ADVERSE REACTIONS, contact Syndax Pharmaceuticals at 1-888-539-3REV or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch. Please see Full Prescribing Information, including BOXED WARNINGS. About Syndax Syndax Pharmaceuticals is a commercial-stage biopharmaceutical company advancing innovative cancer therapies. Highlights of the Company's pipeline include Revuforj® (revumenib), an FDA-approved menin inhibitor, and Niktimvo™ (axatilimab-csfr), an FDA-approved monoclonal antibody that blocks the colony stimulating factor 1 (CSF-1) receptor. Fueled by our commitment to reimagining cancer care, Syndax is working to unlock the full potential of its pipeline and is conducting several clinical trials across the continuum of treatment. For more information, please visit www.syndax.com/ or follow the Company on X and LinkedIn. Forward-Looking Statements This press release contains forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995. Words such as "anticipate," "believe," "could," "estimate," "expects," "intend," "may," "plan," "potential," "predict," "project," "should," "will," "would" or the negative or plural of those terms, and similar expressions (as well as other words or expressions referencing future events, conditions or circumstances) are intended to identify forward-looking statements. These forward-looking statements are based on Syndax's expectations and assumptions as of the date of this press release. Each of these forward-looking statements involves risks and uncertainties. Actual results may differ materially from these forward-looking statements. Forward-looking statements contained in this press release include, but are not limited to, statements about the progress, timing, clinical development and scope of clinical trials, the reporting of clinical data for Syndax's product candidates, the acceptance of Syndax and its partners' products in the marketplace, sales, marketing, manufacturing and distribution requirements, and the potential use of its product candidates to treat various cancer indications and fibrotic diseases. Many factors may cause differences between current expectations and actual results, including: unexpected safety or efficacy data observed during preclinical or clinical trials; clinical trial site activation or enrollment rates that are lower than expected; changes to Revuforj's or Niktimvo’s commercial availability; changes in expected or existing competition; changes in the regulatory environment; failure of Syndax's collaborators to support or advance collaborations or product candidates; and unexpected litigation or other disputes. Other factors that may cause Syndax's actual results to differ from those expressed or implied in the forward-looking statements in this press release are discussed in Syndax's filings with the U.S. Securities and Exchange Commission, including the "Risk Factors" sections contained therein. Except as required by law, Syndax assumes no obligation to update any forward-looking statements contained herein to reflect any change in expectations, even as new information becomes available. Syndax Contact Sharon KlahreSyndax Pharmaceuticals, Inc.sklahre@syndax.com Tel 781.684.9827 SNDX-G
