A Phase 1/2 interventional study of Tazemetostat in Diffuse Large B-cell Lymphoma (DLBCL), Follicular Lymphoma (FL) and Synovial Sarcoma, sponsored by Epizyme, Inc.. Terminated at 34 sites in 7 countries. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-10-28.
Sponsored by Epizyme, Inc. (part of Ipsen) · Phase 1/2, Interventional, and Treatment
Sponsor decision; no additional participant enrollment was anticipated.
This study will provide continuing availability to tazemetostat for people that have previously completed participation in a tazemetostat study, either with monotherapy (single drug treatment) or combination therapy.
The aim of the study will be to assess the long-term safety of tazemetostat.
This open-label, multicenter, global study will provide continuing access to tazemetostat therapy for subjects who have completed their participation in a prior tazemetostat study (either with monotherapy or combination therapy)
without unacceptable toxicity, have not had evidence of tumor progression as defined by disease-appropriate standard criteria, and continue to receive clinical benefit from the therapy.
Subjects will receive tazemetostat as dictated in their antecedent study. Visits will be conducted per Standard of Care (SoC) as appropriate in each country and as determined by the Investigator. Subjects will be followed for long-term safety in addition to time to treatment failure (TTF) and overall survival (OS).
1,868 studies on the registry are indexed under Lymphoma, Large B-Cell, Diffuse; 355 are open to participants now.
This study's enrollment of 58 is above the median of 45 across 1,497 interventional studies indexed under Lymphoma, Large B-Cell, Diffuse.
Browse Lymphoma, Large B-Cell, Diffuse studies →Epizyme, Inc. is the lead sponsor of 21 studies on the registry; none are open to participants now.
Of its 12 completed or terminated interventional studies of FDA-regulated products, 9 (75%) have results posted.
First submitted before Epizyme, Inc. became part of Ipsen.
Counted across the registry records on this site, refreshed daily.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Subjects meeting ANY of the following criteria must NOT be enrolled in this study:
Has another other than the one for which they are receiving tazemetostat.
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
A drug or device being studied in a clinical trial.
It may be new, or already approved and being studied for another use, dose or form. Criteria often leave out people who took part in another study of one within a recent period, commonly 30 days or five half-lives.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
The study doctor’s estimate of how long someone is likely to live. Criteria use it so that people can stay in the study long enough for it to answer its question.
Malignancy means cancer. Criteria about another or earlier malignancy ask whether you have had a different cancer, usually within a set number of years.
Some are commonly allowed, such as treated skin cancers other than melanoma and early cancers removed completely — check the exceptions this study lists.
The US National Cancer Institute’s scale of how severe an adverse event is — any unwanted medical event during a study, such as a symptom, an illness or an abnormal test result, whether or not a treatment caused it. Whether it did is judged separately.
“Side effects of earlier treatment resolved to grade 1 or less” means they have settled to mild or gone.
Investigational drug or device
A drug or device being studied in a clinical trial.
It may be new, or already approved and being studied for another use, dose or form. Criteria often leave out people who took part in another study of one within a recent period, commonly 30 days or five half-lives.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Life expectancy
The study doctor’s estimate of how long someone is likely to live. Criteria use it so that people can stay in the study long enough for it to answer its question.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Cancer (malignancy)
Malignancy means cancer. Criteria about another or earlier malignancy ask whether you have had a different cancer, usually within a set number of years.
Some are commonly allowed, such as treated skin cancers other than melanoma and early cancers removed completely — check the exceptions this study lists.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
CTCAE grade
The US National Cancer Institute’s scale of how severe an adverse event is — any unwanted medical event during a study, such as a symptom, an illness or an abnormal test result, whether or not a treatment caused it. Whether it did is judged separately.
“Side effects of earlier treatment resolved to grade 1 or less” means they have settled to mild or gone.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Participants will continue to receive the same tazemetostat dose and schedule as specified in their antecedent tazemetostat protocol. For participants on combination therapy, the other therapeutic(s) must have been completed in the antecedent study or be provided by a source other than Epizyme if combination treatment is continued in this clinical rollover study.
Drug: Tazemetostat
Tazemetostat (EPZ-6438) is a selective small molecule inhibitor of enhancer of Zeste homolog 2 (EZH2), a histone-lysine N-methyltransferase enzyme.
Also known as: EPZ-6438, E7438, IPN60200
Number of Participants With Treatment-Emergent Adverse Events (TEAEs) and Treatment-Emergent Serious Adverse Events (TESAEs)
An adverse event (AE) is any untoward medical occurrence in a participant or clinical investigation participant administered a medicinal product and which does not necessarily have to have a causal relationship with this treatment. A serious AE is any untoward medical occurrence that, at any dose; resulted in death or was life-threatening or required hospitalization or prolongation of existing hospitalization or resulted in disability/incapacity or was a congenital anomaly/birth defect or any important medical event. Since the first dose of tazemetostat had occurred in the antecedent study, only TEAEs that started within 30 days of permanently stopping tazemetostat or before initiation of subsequent anticancer therapy are reported.
Time frame: From the first dose of study treatment (Day 1 of the rollover study) up to early termination of the study, maximum treatment duration was 96 weeks (tazemetostat <=600 mg BD), 355.4 weeks (tazemetostat 800 mg BD) and 42.9 weeks (tazemetostat 1200 mg BD).
Number of Participants With Treatment-Emergent Adverse Events of Special Interest (TEAESIs)
The TEAESIs are AEs that may not be serious but are of special importance to a particular drug or class of drugs. A prompt medical evaluation of all individual AESI cases, regardless of causality or expectedness is mandatory and reported on both an aggregate and continuous basis. Since the first dose of tazemetostat had occurred in the antecedent study, only TEAEs that started within 30 days of permanently stopping tazemetostat or before initiation of subsequent anticancer therapy are reported.
Time frame: From the first dose of study treatment (Day 1 of the rollover study) up to early termination of the study, maximum treatment duration was 96 weeks (tazemetostat <=600 mg BD), 355.4 weeks (tazemetostat 800 mg BD) and 42.9 weeks (tazemetostat 1200 mg BD).
Duration of Study Treatment Exposure in Rollover Study
The duration of exposure to study treatment on the rollover study was calculated as date of last dose of study treatment minus date of first dose of study treatment on the rollover study + 1. Weeks of exposure in the rollover study was calculated as (date of last dose - date of first dose in the rollover study + 1)/7. The mean study treatment exposure duration was reported.
Time frame: From the first dose of study treatment (Day 1 of the rollover study) up to early termination of the study, maximum treatment duration was 96 weeks (tazemetostat <=600 mg BD), 355.4 weeks (tazemetostat 800 mg BD) and 42.9 weeks (tazemetostat 1200 mg BD).
Overall Survival
The OS was defined as the interval of time between the date of onset (single arm studies: the first dose of tazemetostat; randomized studies: date of randomization) and the date of death due to any cause. The OS in years was defined as (date of death - date of onset)/365.25.
Time frame: From the first dose of study treatment (Day 1 of the antecedent study) up to early termination of the study, approximately 9 years and 1 month.
This was an open-label, multicenter rollover study for Phases 1 and 2, conducted in participants who continued to receive benefit from tazemetostat at 30 centers in 7 countries between 30 August 2016 and 26 September 2025.
| Milestone | Not Treated | Tazemetostat <=600 mg BD | Tazemetostat 800 mg BD | Tazemetostat 1200 mg BD |
|---|---|---|---|---|
| Started | 1 | 13 | 41 | 3 |
| Completed | 0 | 0 | 0 | 0 |
| Not completed | 1 | 13 | 41 | 3 |
| Withdrew: Participant started another anti-cancer therapy | 0 | 4 | 16 | 0 |
| Withdrew: Death | 0 | 5 | 13 | 1 |
| Withdrew: Study terminated by sponsor | 1 | 1 | 6 | 2 |
| Withdrew: Withdrawal by subject | 0 | 3 | 3 | 0 |
| Withdrew: Lost to follow-up | 0 | 0 | 2 | 0 |
| Withdrew: Physician decision | 0 | 0 | 1 | 0 |
An adverse event (AE) is any untoward medical occurrence in a participant or clinical investigation participant administered a medicinal product and which does not necessarily have to have a causal relationship with this treatment. A serious AE is any untoward medical occurrence that, at any dose; resulted in death or was life-threatening or required hospitalization or prolongation of existing hospitalization or resulted in disability/incapacity or was a congenital anomaly/birth defect or any important medical event. Since the first dose of tazemetostat had occurred in the antecedent study, only TEAEs that started within 30 days of permanently stopping tazemetostat or before initiation of subsequent anticancer therapy are reported.
| Participants | Not Treated | Tazemetostat <=600 mg BD | Tazemetostat 800 mg BD | Tazemetostat 1200 mg BD |
|---|---|---|---|---|
| Any TEAEs | — | 13 | 39 | 3 |
| Any TESAEs | — | 4 | 21 | 2 |
The TEAESIs are AEs that may not be serious but are of special importance to a particular drug or class of drugs. A prompt medical evaluation of all individual AESI cases, regardless of causality or expectedness is mandatory and reported on both an aggregate and continuous basis. Since the first dose of tazemetostat had occurred in the antecedent study, only TEAEs that started within 30 days of permanently stopping tazemetostat or before initiation of subsequent anticancer therapy are reported.
| Participants | Not Treated | Tazemetostat <=600 mg BD | Tazemetostat 800 mg BD | Tazemetostat 1200 mg BD |
|---|---|---|---|---|
| Myelodysplastic syndrome | — | 0 | 5 | 1 |
| Acute myeloid leukaemia | — | 1 | 1 | 0 |
| Acute lymphocytic leukaemia | — | 1 | 0 | 0 |
| Acute monocytic leukaemia | — | 0 | 1 | 0 |
| Essential thrombocythaemia | — | 0 | 1 | 0 |
| Myelofibrosis | — | 0 | 1 | 0 |
| Second primary malignancy | — | 0 | 1 | 0 |
The duration of exposure to study treatment on the rollover study was calculated as date of last dose of study treatment minus date of first dose of study treatment on the rollover study + 1. Weeks of exposure in the rollover study was calculated as (date of last dose - date of first dose in the rollover study + 1)/7. The mean study treatment exposure duration was reported.
| weeks | Not Treated | Tazemetostat <=600 mg BD | Tazemetostat 800 mg BD | Tazemetostat 1200 mg BD |
|---|---|---|---|---|
| Duration of Study Treatment Exposure in Rollover Study | — | 39.64 ± 30.965 | 104.20 ± 89.689 | 34.33 ± 8.232 |
The OS was defined as the interval of time between the date of onset (single arm studies: the first dose of tazemetostat; randomized studies: date of randomization) and the date of death due to any cause. The OS in years was defined as (date of death - date of onset)/365.25.
| years | Not Treated | Tazemetostat <=600 mg BD | Tazemetostat 800 mg BD | Tazemetostat 1200 mg BD |
|---|---|---|---|---|
| Overall Survival | NA (0 to NA) | 5.5 (1.9 to NA) | 8.7 (6.0 to NA) | NA (4.1 to NA) |
Collected over TEAEs were collected from first dose of study treatment (Day 1 of rollover study) up to 30 days after last dose or before subsequent anti-cancer therapy, approximately 100 weeks (tazemetostat <=600mg BD), 360 weeks (tazemetostat 800mg BD) and 47 weeks (tazemetostat 1200mg BD). All-cause mortality was collected from first dose (single-arm antecedent studies) or randomization (randomized antecedent studies) until study termination, maximum observation period was approximately 9 years and 1 month.. Non-serious events are listed at a 5% frequency threshold.
| Group | Deaths | Serious | Other |
|---|---|---|---|
| Not Treated | 0/1 (0%) | — | — |
| Tazemetostat <=600 mg BD | 5/13 (38.5%) | 4/13 (30.8%) | 13/13 (100%) |
| Tazemetostat 800 mg BD | 13/41 (31.7%) | 21/41 (51.2%) | 39/41 (95.1%) |
| Tazemetostat 1200 mg BD | 1/3 (33.3%) | 2/3 (66.7%) | 3/3 (100%) |
| Event | Not Treated | Tazemetostat <=600 mg BD | Tazemetostat 800 mg BD | Tazemetostat 1200 mg BD |
|---|---|---|---|---|
| Myelodysplastic syndromeNeoplasms benign, malignant and unspecified (incl cysts and polyps) | — | 0/13 | 3/41 | 1/3 |
| SepsisInfections and infestations | — | 1/13 | 0/41 | 1/3 |
| COVID-19Infections and infestations | — | 0/13 | 0/41 | 1/3 |
| ColitisGastrointestinal disorders | — | 0/13 | 0/41 | 1/3 |
| Lower gastrointestinal haemorrhageGastrointestinal disorders | — | 0/13 | 0/41 | 1/3 |
| Cerebrovascular accidentNervous system disorders | — | 0/13 | 1/41 | 1/3 |
| SyncopeNervous system disorders | — | 0/13 | 0/41 | 1/3 |
| Platelet count decreasedInvestigations | — | 0/13 | 0/41 | 1/3 |
| Acute lymphocytic leukaemiaNeoplasms benign, malignant and unspecified (incl cysts and polyps) | — | 1/13 | 0/41 | 0/3 |
| Peritonitis bacterialInfections and infestations | — | 1/13 | 0/41 | 0/3 |
| Event | Not Treated | Tazemetostat <=600 mg BD | Tazemetostat 800 mg BD | Tazemetostat 1200 mg BD |
|---|---|---|---|---|
| FatigueGeneral disorders | — | 5/13 | 11/41 | 3/3 |
| NauseaGastrointestinal disorders | — | 1/13 | 8/41 | 2/3 |
| AnaemiaBlood and lymphatic system disorders | — | 3/13 | 8/41 | 2/3 |
| Platelet count decreasedInvestigations | — | 1/13 | 1/41 | 2/3 |
| HypokalaemiaMetabolism and nutrition disorders | — | 1/13 | 1/41 | 2/3 |
| Upper respiratory tract infectionInfections and infestations | — | 1/13 | 5/41 | 1/3 |
| PyrexiaGeneral disorders | — | 2/13 | 2/41 | 1/3 |
| ConstipationGastrointestinal disorders | — | 0/13 | 7/41 | 1/3 |
| Rash maculo-papularSkin and subcutaneous tissue disorders | — | 0/13 | 2/41 | 1/3 |
| DysgeusiaNervous system disorders | — | 0/13 | 3/41 | 1/3 |
The enrolled population included all participants who signed informed consent and met all inclusion/exclusion criteria.
| Age, Continuous(years) | Not Treated | Tazemetostat <=600 mg BD | Tazemetostat 800 mg BD | Tazemetostat 1200 mg BD | Total |
|---|---|---|---|---|---|
| Mean | 42.0 | 60.0 ± 19.74 | 60.7 ± 16.06 | 81.7 ± 5.77 | 61.3 ± 17.12 |
| Sex: Female, Male(Participants) | Not Treated | Tazemetostat <=600 mg BD | Tazemetostat 800 mg BD | Tazemetostat 1200 mg BD | Total |
|---|---|---|---|---|---|
| Female | 0 | 4 | 18 | 0 | 22 |
| Male | 1 | 9 | 23 | 3 | 36 |
| Race/Ethnicity, Customized(Participants) | Not Treated | Tazemetostat <=600 mg BD | Tazemetostat 800 mg BD | Tazemetostat 1200 mg BD | Total |
|---|---|---|---|---|---|
| White | 0 | 11 | 30 | 2 | 43 |
| Black or African American | 0 | 1 | 1 | 1 | 3 |
| Asian | 1 | 0 | 1 | 0 | 2 |
| Other | 0 | 1 | 9 | 0 | 10 |
| Race/Ethnicity, Customized(Participants) | Not Treated | Tazemetostat <=600 mg BD | Tazemetostat 800 mg BD | Tazemetostat 1200 mg BD | Total |
|---|---|---|---|---|---|
| Hispanic or Latino | 0 | 0 | 1 | 0 | 1 |
| Not Hispanic or Latino | 1 | 9 | 29 | 3 | 42 |
| Not Reported | 0 | 3 | 10 | 0 | 13 |
| Unknown | 0 | 1 | 1 | 0 | 2 |
PDFs hosted by the registry, ClinicalTrials.gov.
Plan to share: Yes — Qualified researchers may request access to patient level data and related study documents including the clinical study report, study protocol with any amendments, annotated case report form, statistical analysis plan, and dataset specifications. Patient level data will be anonymized and study documents will be redacted to protect the privacy of study participants.
Time frame: Where applicable, data from eligible studies are available 6 months after the studied medicine and indication have been approved in the US and/or EU.
Access criteria: Further details on Ipsen's sharing criteria and process for sharing are available here (https://www.ipsen.com/science/clinical-trials/clinical-data-transparency/).
Data sharing details ↗ · www.ipsen.com
Sponsor decision; no additional participant enrollment was anticipated.
Sponsor decision; no additional participant enrollment was anticipated.
From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗
This study is terminated, as verified in Oct 2026. You cannot join it, but the record below documents what was studied.
Get an email when the registry record changes — status, dates, results — or when someone posts here.
Sign in to followQuestions and observations about this study, from anyone following it. Not medical advice, and not a channel to the study team — their contact details are on the registry record.
Sign in to join the discussion. Reading takes no account; posting does. You choose a display name, and a pseudonym is the default.
Nothing here yet. If you are running this trial, taking part in it, or weighing whether to, this is the place to say so.
Studies of the drug tested here: Tazemetostat
Lymphoma, Large B-Cell, Diffuse →