Sponsor: Novartis Pharmaceuticals (industry)
Phase: 1/2
Start date: Sept. 18, 2019
Planned enrollment: 275
Tulmimetostat (CPI-0209; DZR123) is an investigational, oral, next‑generation inhibitor of the epigenetic targets EZH2 and EZH1, being studied as monotherapy across solid tumors and lymphomas with molecular contexts such as ARID1A mutation or BAP1 loss. The ongoing first‑in‑human phase 1/2 trial (NCT04104776) remains active/recruiting (last update May 15, 2025). The FDA granted Fast Track designation in September 2023 for ARID1A‑mutated advanced/recurrent/metastatic endometrial cancer after at least one prior therapy. (novartis.com, morphosys.com)
Tulmimetostat is a potent, selective, orally available dual EZH2/EZH1 inhibitor designed to provide comprehensive and durable target coverage (prolonged residence time), resulting in sustained reduction of H3K27me3 and re‑expression of silenced genes. Preclinical work demonstrated preferential activity in ARID1A‑mutant models and efficacy in multiple ARID1A‑mutant endometrial tumor models, with supportive phase 1 pharmacokinetic/pharmacodynamic data showing durable exposure and robust target engagement in patients. (aacrjournals.org)
Metastatic castration‑resistant prostate cancer: no confirmed responses in 9 evaluable patients. Using a Simon two‑stage design, the ovarian, endometrial, and mesothelioma cohorts met the prespecified threshold (≥1 objective response in stage 1) for expansion. (ascopubs.org)
Phase 1 dose escalation (ASCO 2021): Antitumor activity signals were noted across multiple tumor types, and 350 mg once daily was selected as the recommended phase 2 dose. (ascopubs.org)
Note: Company and trade‑press summaries have described additional responses at later interim reviews, but peer‑reviewed or meeting‑abstract details beyond the ASCO 2023 dataset remain limited. (biospace.com)
Phase 2 preliminary (ASCO 2023): The most frequent treatment‑emergent adverse events (any grade/grade ≥3) at least possibly related to tulmimetostat were thrombocytopenia (51.6%/27.4%), diarrhea (45.2%/12.9%), nausea (37.1%/0%), anemia (30.6%/16.1%), fatigue (29.0%/0%), alopecia (25.8%/1.6%), dysgeusia (24.2%/0%), vomiting (21.0%/0%), and neutropenia (17.7%/14.5%). Dose modifications occurred in 75.8%, serious AEs in 32.3%, and discontinuations due to AEs in 8.1%. (ascopubs.org)
Phase 1 (ASCO 2021): Generally tolerable; thrombocytopenia was dose‑dependent and reversible. One dose‑limiting toxicity (grade 4 thrombocytopenia) occurred at the highest dose tested (375 mg). (ascopubs.org)
Disclosure: Some sources above are sponsor communications; primary scientific abstracts and peer‑reviewed articles were prioritized where available.
Last updated: Sep 2025
Goal: Evaluate safety, tolerability, pharmacokinetics/pharmacodynamics, and preliminary antitumor activity of tulmimetostat (CPI-0209, DZR123) as monotherapy across advanced solid tumors and lymphomas, and in combination with enzalutamide in metastatic castration-resistant prostate cancer (mCRPC). Phase 1 seeks MTD/RP2D; Phase 2 assesses efficacy in molecularly and disease-defined cohorts, includes dose optimization, and explores food effect in endometrial cancer.
Patients: Adults with ECOG 0–1 and adequate organ function. Phase 1 includes relapsed/refractory or no-standard-option advanced solid tumors or lymphomas. Phase 2 cohorts: M1 urothelial/other ARID1A-mutant solid tumors; M2 ovarian clear cell carcinoma with ARID1A mutation; M3 endometrial carcinoma with ARID1A mutation; M4 relapsed/refractory PTCL or DLBCL (including GCB-DLBCL with EZH2 hotspot mutation) not candidates for CAR-T/ASCT; M5 malignant pleural or peritoneal mesothelioma with BAP1 loss; M6 mCRPC with measurable soft tissue disease after at least one ARSI and one taxane; M7 ARID1A wild-type endometrial carcinoma for food-effect assessment with limited prior lines; M8 mCRPC for combo with enzalutamide with specific prior ARPI/chemotherapy allowances by part. Key exclusions include prior EZH2 inhibitor, significant cardiovascular disease/QTc prolongation, uncontrolled infections, CNS disease (restrictions vary), and GI conditions affecting absorption; additional mCRPC- and combo-specific exclusions apply.
Design: Open-label, multicenter, first-in-human Phase 1/2. Phase 1 monotherapy dose escalation to determine MTD/RP2D (non-randomized). Phase 2 monotherapy expansion uses Simon two-stage designs in most disease cohorts (M1, M2, M3, M5, M6) and single-stage in lymphoma (M4). Phase 2 dose optimization in M2 and M3 includes randomization between two once-daily dose levels (Stage 2a 1:1; potential Stage 2b expansion). Cohort M7 assesses food effect. Cohort M8 evaluates combo safety via dose escalation (Part 1, non-randomized) then randomized Part 2 at RP2D combination to characterize activity in mCRPC.
Treatments: Tulmimetostat is an oral, next-generation dual EZH2/EZH1 inhibitor designed for comprehensive, durable target engagement leading to sustained H3K27me3 reduction and gene re-expression. Early-phase results show signals of activity in ARID1A-mutant endometrial and ovarian clear cell carcinomas, mesothelioma with BAP1 loss, and PTCL; cohorts meeting prespecified activity thresholds have expanded. Safety to date is manageable, with thrombocytopenia, diarrhea, anemia, and neutropenia as prominent adverse events; 350 mg once daily has been used as a recommended Phase 2 dose. In Cohort M8, tulmimetostat is combined with enzalutamide to evaluate safety, PK interactions, and preliminary antitumor activity in mCRPC. All treatments are administered orally once daily in 28-day cycles.
Outcomes: Primary outcomes: Phase 1 monotherapy and M8 Part 1 combination—DLT frequency to define MTD/RP2D; Phase 2 monotherapy—ORR by RECIST 1.1 or applicable criteria per cohort; M8 Part 2—ORR by PCWG3. Secondary outcomes include safety (AE incidence), PK parameters (Cmax, Tmax, AUC0–last, AUC0–inf, T1/2, Cmin), PD markers (gene expression, H3K27me3), and antitumor efficacy endpoints (PFS, TTP, DOR, TTR, DCR, OS; GCIG CA-125 for ovarian cohorts; PCWG3 measures, PSA50 response and time to PSA progression in prostate cohorts). Cohort M7 specifically assesses the effect of a high-fat, high-calorie meal on tulmimetostat PK.
Burden on patient: High. As a Phase 1/2 FIH program, patients should expect intensive early-cycle visits with frequent PK blood draws (including troughs and serial sampling), PD assessments (e.g., H3K27me3 and gene expression in blood; potential optional tissue sampling per site practice), and close AE monitoring with possible dose modifications. Imaging for response per RECIST/PCWG3 at regular intervals adds visit frequency. Cohort M7 includes structured fed/fasted dosing periods necessitating timed visits and fasting windows. Combination cohorts require additional safety checks and PK for both agents. Overall, oral therapy reduces infusion burden, but travel and phlebotomy demand is substantial, especially during dose-escalation and optimization stages.
Key Inclusion Criteria:
* Eligible Phase 1 patients are adults who have a confirmed locally advanced or metastatic tumors (solid tumors or lymphoma) that have relapsed following standard therapy or progressed through standard therapy or who have a disease for which no standard effective therapy exists.
* Eligible Phase 2 patients in cohorts M1 to M3 are adults who are known to have the ARID1A mutation by next-generation sequencing (NGS) testing; have measurable disease per Response Evaluation Criteria in Solid Tumors 1.1 and who have confirmed relapsed urothelial or other advanced/metastatic solid tumors (M1), ovarian clear cell carcinoma (M2), or endometrial carcinoma (M3).
* Eligible Phase 2 patients in Cohort M4 are adults who have either relapsed or refractory PTCL (at least 10 patients) or DLBCL (up to 10 patients), including patients with documented GCB DLBCL with EZH2 hotspot mutation. Patients with PTCL must have at least 1 prior line of therapy and patients with DLBCL must have at least 2 prior lines of standard therapy; and are not considered candidates to receive CAR-T or ASCT therapy.
* Eligible Phase 2 patients in Cohort M5 are adults who are known to the have the BAP1 loss, have malignant pleural or peritoneal mesothelioma, and have progressed on at least 1 prior line of active therapy.
* Eligible Phase 2 patients in Cohort M6 are adults who have mCRPC with measurable soft tissue disease with CT scan as defined by PCWG3 criteria, have baseline testosterone levels ≤ 50 ng/dL (≤ 2.0 nM) and have surgical or ongoing medical castration and who have progressed on at least 1 androgen-receptor signaling inhibitor and at least 1 taxane-based chemotherapy (cabazitaxel, France only).
* Eligible Phase 2 patients in Cohort M7 are adults with recurrent, advanced ARID1A WT endometrial carcinoma confirmed by NGS testing and have measurable disease per Response Evaluation Criteria in Solid Tumors 1.1 Patients will be enrolled with maximum up to 2 prior lines of systemic therapy for treating endometrial carcinoma that must include at least one treatment line with systemic platinum-based chemotherapy in advanced/ recurrent disease setting, and anti-programmed cell death protein 1 (PD-1)/ anti-programmed death-ligand 1 (PD-L1) therapy, either in combination or separately, unless these are contraindicated or are not locally accessible.
* Eligible Part 1 and Part 2 patients in Cohort M8 are adults who have mCRPC with measurable soft tissue disease as per PCWG3 criteria, have baseline testosterone levels ≤ 50 ng/dL (≤ 2.0 nM), have surgical or ongoing medical castration or hormone sensitive prostate cancer (HSPC) disease stage. In addition, Eligible part 1 patients in Cohort M8 may have received abiraterone treatment in mCRPC while eligible part 2 patients in Cohort M8 must have received abiraterone treatment in mCRPC. In addition, only for M8 Part 1: Patients may have received no more than one previous regimen of taxane-based chemotherapy in mCRPC or HSPC setting. For M8 Part 2: Patients may have received no more than one previous regimen of taxane-based chemotherapy in HSPC setting. Patients for both M8 Part 1 and M8 Part 2 must have evidence of prostate cancer progression (per PCWG3) and must have ongoing ADT (androgen deprivation therapy) with a GnRH analogue, antagonist or bilateral orchiectomy (i.e., surgical or medical castration).
* All patients will have Eastern Cooperative Oncology Group (ECOG) performance status of ≤ 1 and adequate organ function.
Key Exclusion Criteria:
1. Medical Conditions
* Previous solid organ or allogeneic hematopoietic cell transplantation (HCT).
* Known symptomatic untreated brain metastases. Patients with central nervous system (CNS) metastases must have stable neurologic status following local therapy for at least 4 weeks on a stable or decreasing dose of steroids (≤ 10 mg daily prednisone or equivalent). Patients in the M4 lymphoma cohort are excluded if they have known CNS involvement by lymphoma.
* Clinically significant cardiovascular disease, including:
* Myocardial infarction or stroke within 3 months (6 months for M8 cohort) prior to Day 1 of treatment.
* Unstable angina within 3 months (6 months for M8 cohort) prior to Day 1 of treatment.
* Congestive heart failure or cardiomyopathy with New York Heart Association (NYHA) Class 3 or 4.
* History of clinically significant ventricular arrhythmias (e.g., ventricular tachycardia, ventricular fibrillation, torsades de pointes).
* Uncontrolled hypertension despite 2 concomitant antihypertensive therapies.
* For Cohorts M1-M6: QT interval corrected by the Fridericia correction formula (QTcF) \> 480 msec on the Screening ECG.
* For Cohorts M7 and M8: QTcF interval ≥ 450 msec at screening.
* Major surgery within 4 weeks before starting study drug or not recovered from any effects of prior major surgery (uncomplicated central line placement or fine needle aspirate are not considered major surgery).
* Gastrointestinal disorders that may significantly interfere with the absorption of the study medication, such as ulcerative colitis, malabsorption syndrome, refractory nausea and vomiting, biliary shunt, significant bowel resection.
* Uncontrolled active infection requiring intravenous antibiotic, antiviral, or antifungal medications within 14 days before the first dose of study drug. Controlled infections on concurrent antimicrobial agents and antimicrobial prophylaxis per institutional guidelines are acceptable.
* Suspected pneumonitis or interstitial lung disease (confirmed by radiography or CT) or a history of these conditions.
* History of a concurrent or second malignancy except for certain adequately treated cancers such as local basal cell or squamous cell carcinoma of the skin, cervical carcinoma in situ, superficial bladder cancer, asymptomatic prostate cancer without known metastatic disease, adequately treated Stage 1 or 2 cancer currently in complete remission, or any other cancer in complete remission for ≥ 3 years. Patients with a history of T-cell lymphoblastic lymphoma or T-cell lymphoblastic leukemia are not eligible.
* Current known active or chronic infection with HIV, hepatitis B, or hepatitis C. Screening for these viruses is not required unless there is a past history or current suspicion of viral hepatitis.
* Clinically active or symptomatic viral hepatitis or chronic liver disease.
* Unstable or severe uncontrolled medical condition or any important medical or psychiatric illness or abnormal laboratory finding that would increase the risk to the patient associated with participation in the study.
* For Cohort M7 Only: Patients not willing to or cannot remain fasted due to a medical condition for 2 hours before and 1 hour after dose administration.
2. Prior/Concomitant Therapy:
* Prior Anticancer Treatment:
* Systemic Anticancer Treatment: Patients must not have received chemotherapy, targeted therapy, small molecules, antibodies, investigational anticancer therapy, or other anticancer therapeutics (except gonadotropin-releasing hormone analogues) within 4 weeks (or 5 half-lives, whichever is shorter) before the first dose of the study drug. For nitrosoureas or mitomycin C, a 6-week washout is required. For prior PD-1 or PD-L1 therapy, a washout period of at least 4 weeks is acceptable. All toxicities from prior therapies must have resolved to Grade 1 or less, except for endocrinopathies requiring medication, neuropathy, and alopecia, which must have resolved to Grade 2 or less.
* EZH2 Inhibitor: Previous treatment with an EZH2 inhibitor is not allowed.
* Radiation Therapy: Patients must not have received radiation therapy (including radiofrequency ablation) within 4 weeks before the first dose of the study drug. However, a single fraction of radiotherapy for palliation confined to one field is permitted within 1 week prior to Day 1 of treatment.
* Stereotactic Body Radiation Therapy: Patients must not have received this therapy within 2 weeks before the first dose of the study drug.
* Chemoembolization or Radioembolization: Patients must not have received these treatments within 4 weeks before the first dose of the study drug.
* Concomitant Medication:
* CYP3A4/5 Inducers or Inhibitors: Patients must not take strong CYP3A4/5 inducers or inhibitors (except enzalutamide in Cohort M8) within 7 days or 5 times the reported half-life of the CYP3A4/5 inhibitor or inducer (whichever is longer) prior to the first dose of the study drug and for the duration of the study.
3. Other Exclusions
* General Exclusions:
* Pregnancy and Breastfeeding: Patients who are breastfeeding, pregnant (as confirmed by a serum β-hCG pregnancy test within 72 hours prior to the first dose of the study drug), or planning to conceive or father children during the trial and for 183 days after the last dose of the study drug are excluded. Women of nonchildbearing potential (post-menopausal for more than 1 year or surgically sterilized) do not require a serum pregnancy test. A highly sensitive urine test can be used if a serum test is not appropriate. Female patients with false-positive β-hCG values may be enrolled with written consent from the Sponsor's Medical Monitor after pregnancy has been excluded.
* Compliance: Patients who are unwilling or unable to comply with the study protocol or requirements are excluded.
* Additional Exclusions for Cohort M6 (mCRPC) Only:
* Bone-only Disease: Patients with bone-only disease without nodal disease and no evidence of visceral spread are excluded.
* Structurally Unstable Bone Lesions: Patients with bone lesions that are structurally unstable and concerning for impending fracture are excluded.
* Herbal Products: Patients using herbal products that may decrease prostate-specific antigen (PSA) levels within 4 weeks prior to Day 1 of treatment and during the study are excluded.
* Prostate Cancer Treatments: Patients who have received the following treatments for prostate cancer within the specified timeframes prior to Day 1 of treatment are excluded:
1. First-generation androgen receptor antagonists (e.g., bicalutamide, nilutamide, flutamide) within 4 weeks.
2. 5α reductase inhibitors, ketoconazole, estrogens (including diethylstilbestrol), or progesterones within 2 weeks.
* Planned Palliative Procedures: Patients with planned palliative procedures for alleviation of bone pain, such as radiation therapy or surgery, are excluded.
4. Additional Exclusion Criteria for Cohort M8 (DZR123 and Enzalutamide Combination in mCRPC) only:
* Biochemical recurrence/prostate-specific antigen (PSA)-only disease.
* Prior Enzalutamide Treatment:
* For M8 Part 1: Patients who have received prior enzalutamide.
* For M8 Part 2: Patients who have received prior enzalutamide, apalutamide, darolutamide, or any other investigational androgen receptor pathway inhibitor (ARPi).
* Herbal Products: Use of herbal products that may decrease PSA levels within 4 weeks prior to Day 1 of treatment and during the study.
* Planned Palliative Procedures: Planned palliative procedures for alleviation of bone pain, such as radiation therapy or surgery.
* Investigational Agents: Treatment with any investigational agent within 4 weeks before Day 1 of M8 Part 1 or M8 Part 2.
* Bone Marrow Irradiation: Prior irradiation to more than 25% of the bone marrow.
* Gastrointestinal Conditions: Active inflammatory gastrointestinal disease, chronic diarrhea, known diverticular disease, or previous gastric resection or lap band surgery. Gastroesophageal reflux disease under treatment with proton pump inhibitors is allowed.
* Seizure History: History of seizure, loss of consciousness, or transient ischemic attack within 12 months of study entry, or any condition that may predispose to seizure (e.g., stroke, brain arteriovenous malformation, head trauma, underlying brain injury).
Bordeaux, 33000, France
[email protected] / +33 (556) 333-282
Status: Recruiting
Villejuif, 94805, France
[email protected] / +33 (0) 142 11 61 72
Status: Recruiting
Strasbourg, 67200, France
[email protected] / +33 (0) 368767150
Status: Recruiting
Saint-Herblain, 44800, France
[email protected] / +33 (0) 2 40 16 56 98
Status: Recruiting
Nantes, 44093, France
[email protected] / +33 (0) 240 08 40 30
Status: Recruiting
Nantes, 44093, France
[email protected] / +33 (0) 2 53 48 22 43
Status: Recruiting
Lyon, 69373, France
[email protected] / +33 (0) 4 78 78 20 62
Status: Recruiting
Lille, 59020, France
[email protected] / +33 (0) 3 20 29 56 38
Status: Recruiting
Bologna, 40138, Italy
[email protected] / 39 051 214 3231
Status: Recruiting
Rozzano, 20089, Italy
[email protected] / 39 02 8224 5954
Status: Recruiting
Rome, 00168, Italy
[email protected] / +39 (06) 30158 545
Status: Recruiting
Milan, 20141, Italy
[email protected] / +39 (029) 4372-183
Status: Recruiting
Milan, 20133, Italy
[email protected] / No phone
Status: Recruiting
Warsaw, 02-781, Poland
[email protected] / 0048 22 546 2223
Status: Recruiting
Skorzewo, 60-185, Poland
[email protected] / 0048 512 491 461
Status: Recruiting
Poznan, 60-569, Poland
[email protected] / 0048 574432284
Status: Recruiting
Lodz, 93-338, Poland
[email protected] / 0048 792 206 646
Status: Recruiting
Gdansk, 80-214, Poland
[email protected] / 48 58 584 44 17
Status: Recruiting
Seoul, 03080, South Korea
[email protected] / 010-9266-2851
Status: Recruiting
Incheon, 21565, South Korea
[email protected] / 010-7583-3119
Status: Recruiting
Goyang-si, 10408, South Korea
[email protected] / 82-31-920-0859
Status: Recruiting
Seoul, 03722, South Korea
[email protected] / 82 22-228-2759
Status: Recruiting
Seoul, 05505, South Korea
[email protected] / 82-22-045-3855
Status: Recruiting
Seoul, 06273, South Korea
[email protected] / 8210-8737-0811
Status: Recruiting
Daegu, 42601, South Korea
[email protected] / 82 (53) 258 6679
Status: Recruiting
Madrid, 28041, Spain
[email protected] / +34 913908626
Status: Recruiting
Barcelona, 08035, Spain
[email protected] / (+34)93 274 60 00 4691
Status: Recruiting
Girona, 17007, Spain
[email protected] / +34 972 75 49 53
Status: Recruiting
Madrid, 28027, Spain
[email protected] / +34 (91) 353 1920 Ext 7539
Status: Recruiting
Madrid, 28223, Spain
[email protected] / +34 914521900 (ext. 38901)
Status: Recruiting
Palma de Mallorca, 07120, Spain
[email protected] / +34 871 20 61 30
Status: Recruiting
Pamplona, 31008, Spain
[email protected] / +34 (948) 255 400 Ext 2733
Status: Recruiting
Salamanca, 37007, Spain
[email protected] / +34 (923) 291 316
Status: Recruiting
Santiago de Compostela, 15706, Spain
[email protected] / +34981950512/ +3498195567
Status: Recruiting
Seville, 41013, Spain
[email protected] / +34 (696) 635-551
Status: Recruiting
Valencia, 46009, Spain
[email protected] / +34 663224865
Status: Recruiting
Leicester, LE5 4PW, United Kingdom
[email protected] / 0116 258 7598
Status: Recruiting
London, SW7 2AZ, United Kingdom
[email protected] / 0208 383 1366
Status: Recruiting
Manchester, M20 4BX, United Kingdom
No email / No phone
Status: Recruiting
Sutton, SM2 5PT, United Kingdom
[email protected] / 442031865362
Status: Recruiting
Taunton, TA1 5DA, United Kingdom
[email protected] / 01823 342582
Status: Recruiting
Bath, BA1 3NG, United Kingdom
[email protected] / 01225 824288
Status: Recruiting
London, SW3 6JJ, United Kingdom
No email / No phone
Status: Recruiting
Atlanta, Georgia, 30322-1013, United States
[email protected] / 404-712-9858
Status: Recruiting
Chicago, Illinois, 60637, United States
[email protected] / 773-834-6421
Status: Recruiting
Baltimore, Maryland, 21201, United States
No email / No phone
Status: Withdrawn
Boston, Massachusetts, 02215-5450, United States
[email protected] / 857-215-2265
Status: Recruiting
Boston, Massachusetts, 02114, United States
[email protected] / 617-632-9250
Status: Recruiting
Grand Rapids, Michigan, 49546, United States
[email protected] / 616-954-5554
Status: Recruiting
Ann Arbor, Michigan, 48109, United States
No email / No phone
Status: Withdrawn
Hackensack, New Jersey, 07601, United States
[email protected] / 551-996-8170
Status: Recruiting
The Bronx, New York, 10467-2490, United States
No email / No phone
Status: Withdrawn
New York, New York, 10016, United States
[email protected] / 407-517-8471
Status: Recruiting
New York, New York, 10065, United States
No email / No phone
Status: Withdrawn
Cincinnati, Ohio, 45219, United States
No email / No phone
Status: Withdrawn
Philadelphia, Pennsylvania, 19104, United States
No email / No phone
Status: Recruiting
San Antonio, Texas, 78229, United States
[email protected] / 210-593-5270
Status: Recruiting
Charlottesville, Virginia, 22908, United States
[email protected] / 804-683-2880
Status: Recruiting
Seattle, Washington, 98109-1023, United States
[email protected] / 206-606-7494
Status: Recruiting
Seattle, Washington, 98104, United States
[email protected] / 206-215-6430
Status: Recruiting