Clonal Cytopenia of Undetermined SignificancePhase 1NCT05102370
A Study of Enasidenib in People With Clonal Cytopenia of Undetermined Significance
A Phase 1 study testing Enasidenib in people with Clonal Cytopenia of Undetermined Significance and CCUS Clonal Cytopenia of Undetermined Significance, run by Memorial Sloan Kettering Cancer Center at 12 sites in United States.
Trial summary
Study researchers think that a drug called enasidenib may help people with clonal cytopenia of undetermined significance (CCUS) because the drug blocks the mutated IDH2 protein, which may improve blood cell counts. The purpose of this study is to find out whether enasidenib is a safe and effective treatment for CCUS. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Clonal Cytopenia of Undetermined Significance, CCUS Clonal Cytopenia of Undetermined Significance
- What is being tested?
- Enasidenib
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 4 participants
- Where
- 12 sitesUnited States
- Study dates
- 6 Oct 2021to 26 Jan 2026
- Phase
- Phase 1
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Age ≥18 years at the time of signing the informed consent form.
- Willing and able to adhere to the study visit schedule and other protocol requirements.
- Unexplained cytopenia for at least 6 months. Cytopenia is defined as the presence of ≥1 blood count indexes below the following thresholds:
- Hgb <10 g/dL
- ANC <1.8 × 10^9/L
- Platelets <100 × 10^9/L
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- Results of bone marrow biopsy within 1 month of study entry (screening bone marrow biopsy) must not indicate hematologic disease.
- IDH2 gene mutation (R140 or R172), performed locally, at a frequency >2%.
- ECOG performance status of 0-2.
- Adequate organ function, defined as:
- Serum aspartate aminotransferase/serum glutamic oxaloacetic transaminase (AST/SGOT) and alanine aminotransferase (ALT/SGPT) ≤3x upper limit of normal (ULN), unless the subject has Gilbert's syndrome.
- Serum total bilirubin <1.5x ULN. Higher levels are acceptable if these can be attributed to ineffective erythropoiesis. In these cases, approval from the study Principal Investigator is required.
- Creatinine clearance greater than 50 mL/min based on the Cockroft-Gault glomerular filtration rate estimation.
- Patients being enrolled on study on the basis of anemia, will only be eligible if folate, B12, serum iron, serum ferritin, total iron binding capacity, haptoglobin and peripheral smear within normal limits
- Women of childbearing potential may participate provided they have a negative serum pregnancy test at screening and a negative serum or urine pregnancy test within 72 h of starting treatment.
- Women of childbearing potential (WOCBP) and males with partners who are WOCBP must agree to abstain from sexual intercourse or to use 1 highly effective form of contraception during the study and for at least 4 months following the last dose of enasidenib. Males with partners who are WOCBP must agree to use a barrier method.
Who cannot join
- Active malignancy defined as >1-cm disease on most recent CT scan in the past 6 months or recent history of cancer (i.e. within the past 5 years) with >50% chance of cancer recurrence in the next 5 years.
- Current or prior history of hematologic malignancy.
- Therapy (including maintenance therapy) for solid-tumor malignancy within the last 6 months.
- Known dysphagia, short-gut syndrome, gastroparesis, or other conditions that limit the ingestion or gastrointestinal absorption of drugs administered orally.
- Active uncontrolled systemic fungal, bacterial, or viral infection (defined as ongoing signs/symptoms related to the infection without improvement despite appropriate antibiotics, antiviral therapy, and/or other treatment).
- Positive direct Coombs test
- Evidence of hypersplenism on physical exam
- Pregnant or lactating (women).
Trial locations and contacts
12 sites in 1 country.
12 sites in 1 country
United States12 sites
Memorial Sloan Kettering at Basking Ridge (All Protocol Activities)
Basking Ridge, New Jersey, 07920
Cleveland Clinic (Data Collection Only)
Cleveland, Ohio, 44195
Ohio State University (Data Collection Only)
Columbus, Ohio, 43210
Memorial Sloan Kettering Suffolk-Commack (Limited protocol activities)
Commack, New York, 11725
Memorial Sloan Kettering Westchester (All Protocol Activities)
Harrison, New York, 10604
Memorial Sloan Kettering Monmouth (All protocol activities)
Middletown, New Jersey, 07748
Memorial Sloan Kettering Bergen (Limited protocol activities)
Montvale, New Jersey, 07645
Memorial Sloan Kettering Cancer Center (All Protocol Activities)
New York, New York, 10065
Oregon Health & Science University (Data Collection Only)
Portland, Oregon, 97239
Mayo Clinic (Data Collection Only)
Rochester, Minnesota, 55905
Memorial Sloan Kettering Nassau (Limited protocol activities)
Rockville Centre, New York, 11553
Washington University (Data Collection and Specimen Analysis)
St Louis, Missouri, 63110
About this study
Official title: A Pilot Study of Enasidenib for Patients With Clonal Cytopenia of Undetermined Significance and Mutations in IDH2
Study researchers think that a drug called enasidenib may help people with clonal cytopenia of undetermined significance (CCUS) because the drug blocks the mutated IDH2 protein, which may improve blood cell counts. The purpose of this study is to find out whether enasidenib is a safe and effective treatment for CCUS.
- Conditions
- Clonal Cytopenia of Undetermined Significance, CCUS Clonal Cytopenia of Undetermined Significance
- Being tested
- Enasidenib
- Keywords
- CCUS, Clonal Cytopenia of Undetermined Significance, Enasidenib, 21-268, Memorial Sloan Kettering Cancer Center
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
EnasidenibDrug
Study participants will receive enasidenib 100 mg daily for 18 months. Participants will continue treatment with enasidenib until confirmed progression to AML or MDS, development of unacceptable toxicity, or suspicion of disease progression, provided the patient is deriving clinical benefit, which will be determined at the discretion of the principal investigator.
| Study group | Role | What they receive |
|---|---|---|
| Participants with CCUS with mutations in IDH2 | Experimental | Participants will have CCUS with mutations in IDH2 Receives: Drug: Enasidenib |
What is being measured
The primary outcome is the main question the study is designed to answer.
Best Response
The primary objective is to estimate the rate of hematologic improvement. The endpoint is evaluated as the best response at any point in up to 18 months of treatment with enasidenib.
Measured: Up to 18 months
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted1 Nov 2021
- Study start6 Oct 2021
- Primary completion26 Jan 2026
- Study completion26 Jan 2026
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Clonal Cytopenia of Undetermined SignificanceStudies of the same condition, open and under way.
- More trials run by Memorial Sloan Kettering Cancer CenterThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 1
- Primary purpose
- Treatment
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Enrolment
- 4 participants (actual)
Sponsor and investigators
- Lead sponsor
- Memorial Sloan Kettering Cancer Center
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
- Investigators
- Eytan Stein, MD, Principal investigator, Memorial Sloan Kettering Cancer Center
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05102370
- Sponsor's protocol ID
- 21-268
- Status last verified
- Jan 2026
- First submitted
- 20 Oct 2021
- Last updated
- 27 Jan 2026
- Results posted
- No
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- Yes: Memorial Sloan Kettering Cancer Center supports the international committee of medical journal editors (ICMJE) and the ethical obligation of responsible sharing of data from clinical trials. The protocol summary, a statistical summary, and informed consent form will be made available on clinicaltrials.gov when required as a condition of Federal awards, other agreements supporting the research and/or as otherwise required. Requests for deidentified individual participant data can be made beginning 12 months after publication and for up to 36 months post publication. Deidentified individual participant data reported in the manuscript will be shared under the terms of a Data Use Agreement and may only be used for approved proposals. Requests may be made to: crdatashare@mskcc.org.
Study at a glance
From the registry record, last updated by the sponsor on 27 Jan 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- A Pilot Study of Enasidenib for Patients With Clonal Cytopenia of Undetermined Significance and Mutations in IDH2
- ClinicalTrials.gov ID
- NCT05102370
- Acronym / sponsor ID
- 21-268
- Conditions
- Clonal Cytopenia of Undetermined Significance, CCUS Clonal Cytopenia of Undetermined Significance
- Keywords
- CCUS, Clonal Cytopenia of Undetermined Significance, Enasidenib, 21-268, Memorial Sloan Kettering Cancer Center
- Phase
- Phase 1
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 4 participants (actual)
- Lead sponsor
- Memorial Sloan Kettering Cancer CenterUniversity, hospital or other
- Study start
- 6 Oct 2021 (actual)
- Primary completion
- 26 Jan 2026 (actual)
- Study completion
- 26 Jan 2026 (actual)
- First posted
- 1 Nov 2021 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Study researchers think that a drug called enasidenib may help people with clonal cytopenia of undetermined significance (CCUS) because the drug blocks the mutated IDH2 protein, which may improve blood cell counts. The purpose of this study is to find out whether enasidenib is a safe and effective treatment for CCUS.
Study design
- Primary purpose
- Treatment
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Participants with CCUS with mutations in IDH2 | Experimental | Drug: EnasidenibParticipants will have CCUS with mutations in IDH2 |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (16 listed)
- Age ≥18 years at the time of signing the informed consent form.
- Willing and able to adhere to the study visit schedule and other protocol requirements.
- Unexplained cytopenia for at least 6 months. Cytopenia is defined as the presence of ≥1 blood count indexes below the following thresholds:
- Hgb <10 g/dL
- ANC <1.8 × 10^9/L
Key exclusion criteria (8 listed)
- Active malignancy defined as >1-cm disease on most recent CT scan in the past 6 months or recent history of cancer (i.e. within the past 5 years) with >50% chance of cancer recurrence in the next 5 years.
- Current or prior history of hematologic malignancy.
- Therapy (including maintenance therapy) for solid-tumor malignancy within the last 6 months.
- Known dysphagia, short-gut syndrome, gastroparesis, or other conditions that limit the ingestion or gastrointestinal absorption of drugs administered orally.
- Active uncontrolled systemic fungal, bacterial, or viral infection (defined as ongoing signs/symptoms related to the infection without improvement despite appropriate antibiotics, antiviral therapy, and/or other treatment).
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| EnasidenibStudy participants will receive enasidenib 100 mg daily for 18 months. Participants will continue treatment with enasidenib until confirmed progression to AML or MDS, development of unacceptable toxicity, or suspicion of disease progression, provided the patient is deriving clinical benefit, which will be determined at the discretion of the principal investigator. | Drug | Participants with CCUS with mutations in IDH2 |
Primary outcome
Best Response
Time frame: Up to 18 months
The primary objective is to estimate the rate of hematologic improvement. The endpoint is evaluated as the best response at any point in up to 18 months of treatment with enasidenib.
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 27 Jan 2026.
- Memorial Sloan Kettering Cancer CenterLink provided by the sponsor.
- Individual participant dataSharing planned: Yes. Memorial Sloan Kettering Cancer Center supports the international committee of medical journal editors (ICMJE) and the ethical obligation of responsible sharing of data from clinical trials. The protocol summary, a statistical summary, and informed consent form will be made available on clinicaltrials.gov when required as a condition of Federal awards, other agreements supporting the research and/or as otherwise required. Requests for deidentified individual participant data can be made beginning 12 months after publication and for up to 36 months post publication. Deidentified individual participant data reported in the manuscript will be shared under the terms of a Data Use Agreement and may only be used for approved proposals. Requests may be made to: crdatashare@mskcc.org.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Eytan Stein, MD principal investigator
Memorial Sloan Kettering Cancer Center
12 sites in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 1 study testing Enasidenib in people with Clonal Cytopenia of Undetermined Significance and CCUS Clonal Cytopenia of Undetermined Significance, run by Memorial Sloan Kettering Cancer Center at 12 sites in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 16 inclusion and 8 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 27 Jan 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 12 sites in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
Phase 1 studies test a treatment in a small group of people for the first time or in a new way, mainly to check safety and find the right dose.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Best Response (time frame: Up to 18 months). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 27 Jan 2026.