A Study of Mogamulizumab to Prevent Adult T-cell Leukemia/Lymphoma in People With HTLV-1

March 3, 2026 updated by: Memorial Sloan Kettering Cancer Center

A Phase 2 Study for Screening and Prevention of Adult T-cell Leukemia/Lymphoma With Mogamulizumab in High-Risk Carriers of HTLV-1

The purpose of this study is to find out whether the study drug mogamulizumab is effective in preventing the development of adult T-cell leukemia/lymphoma (ATL) in people who are at higher risk for this type of cancer because they are infected with the HTLV-1 virus and because of changes seen in some of their immune system cells called T-cells.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
134

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Phase 2

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Contact Backup

Study Locations

  • United States
    • New Jersey
      • Basking Ridge, New Jersey, United States, 07920
        • Recruiting
        • Memorial Sloan Kettering at Basking Ridge (All Protocol Activities)
        • Contact:
          • Steven Horwitz, MD
          • Phone Number: 646-608-2680
      • Middletown, New Jersey, United States, 07748
        • Recruiting
        • Memorial Sloan Kettering Monmouth (All Protocol Activities)
        • Contact:
          • Steven Horwitz, MD
          • Phone Number: 646-608-2680
      • Montvale, New Jersey, United States, 07645
        • Recruiting
        • Memorial Sloan Kettering Bergen (All Protocol Activities)
        • Contact:
          • Steven Horwitz, MD
          • Phone Number: 646-608-2680
    • New York
      • Commack, New York, United States, 11725
        • Recruiting
        • Memorial Sloan Kettering Cancer Center @ Suffolk-Commack (All Protocol Activities)
        • Contact:
          • Steven Horwitz, MD
          • Phone Number: 646-608-2680
      • Harrison, New York, United States, 10604
        • Recruiting
        • Memorial Sloan Kettering Westchester (All Protocol Activities)
        • Contact:
          • Steven Horwitz, MD
          • Phone Number: 646-608-2680
      • New York, New York, United States, 10065
        • Recruiting
        • Memorial Sloan Kettering Cancer Center (All Protocol Activities)
        • Contact:
          • Steven Horwitz, MD
          • Phone Number: 646-608-2680
      • Uniondale, New York, United States, 11553
        • Recruiting
        • Memorial Sloan Kettering Nassau (All Protocol Activities)
        • Contact:
          • Steven Horwitz, MD
          • Phone Number: 646-608-2680

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

Screening Cohort (US patients only):

  • Age ≥18 years when informed consent is obtained
  • Has freely given written informed consent to participate in the study

Treatment Cohorts (Cohorts 1 and 2):

  • Positive for anti-HTLV-1 antibody in the serum using an FDA approved assay for US patients (Avioq HTLV-I/II Microelisa System). UK patients should use UK Accreditation Service (UKAS) accredited tests, Abbot Architect ELISA Serology Screening assay and confirmatory serology Western Blot (performed at Public Health England, Virus Ref Dept, Colindale).
  • High-risk phenotype (PVL≥8% of PBMC)
  • Age ≥18 years when informed consent is obtained

  • Primary organ functions are stable

    • Neutrophil count: ≥ 1000/mm3, unless patient has diagnosis of ethnic neutropenia
    • Platelets: ≥100,000/mm3
    • Hemoglobin: ≥9.0 g/dL
    • Serum aspartate aminotransferase (AST): ≤1.5x upper limit of normal (ULN)
    • Alanine aminotransferase (ALT): ≤1.5x ULN
    • Total bilirubin: ≤1.5x ULN
    • Serum creatinine (Cr): ≤1.5x ULN
    • Blood oxygen saturation (SpO2): ≥90%
  • Electrocardiogram (ECG): No abnormal findings requiring treatment are observed
  • Has freely given written informed consent to participate in the study
  • For females of reproductive potential: use of effective contraception during treatment and for at least 3 months after completion of mogamulizumab therapy. For males who have sexual intercourse with females of reproductive potential: use of effective contraception during treatment and for at least 3 months after completion of mogamulizumab therapy.

Exclusion Criteria:

In order to protect subjects and avoid any problems in evaluating the study drug, patients who meet any of the following criteria should be excluded from enrollment in the study, in either screening or treatment cohorts:

  • Patients with a history of any of the following:

    • Neutrophil count: ≤1000/mm3, unless patient has diagnosis of ethnic neutropenia
    • Acute or chronic hepatitis or hepatic cirrhosis, other than patients with positive antibodies and negative PCR as noted in criteria #11 and #12 below.
    • Tuberculosis or with active tuberculosis
    • Myocardial infarction within 12 months prior to the date of enrollment
    • Allergic reaction to administration of antibody drug products
    • Other cancers. Patients with a history of a localized solid tumor who received definitive, curative treatment and who have been without evidence of disease for 5 years prior to enrollment will be able to enroll in the study. Patients with radically resected basal cell carcinoma of the skin, squamous cell carcinoma (except malignant melanoma), noninvasive cervix carcinoma, carcinoma in situ in the gastrointestinal tract or corpus of the uterus, localized thyroid cancer, and localized renal cell carcinoma will be able to enroll in the study if they are determined to be completely cured, even if within 5 years of enrollment.
  • Prior treatment with immunosuppressants or interferon alpha products within 6 months prior to the date of enrollment
  • Serious complications (heart failure, lung disease, renal failure, hepatic failure, uncontrolled diabetes mellitus, etc.)
  • History of an active autoimmune disease that has required systemic treatment in past 2 years (ie, with use of disease modifying agents, corticosteroids or immunosuppressive drugs). Replacement therapy (eg, thyroxine, insulin, or physiologic corticosteroid replacement therapy for adrenal or pituitary insufficiency) is not considered a form of systemic treatment and is allowed.
  • Any ailment that could be exacerbated by the administration of KW-0761, in the judgment of the Principal Investigator or co-Investigator
  • Diagnosis of ATL
  • Women who are pregnant, breastfeeding, who may be pregnant, or wish to bear children while receiving treatment or within 3 months of last dose of mogamulizumab
  • Patients who have taken multivitamins (Alinamin, vitamin C, etc.) or supplements such as fucoidan, catechin, and pentosan polysulfate within 2 weeks prior to the date of enrollment
  • Prior treatment with other study drugs within 4 months prior to giving informed consent
  • Complications of spinal cord compressive lesions such as cervical spine disease, disc herniation, and ossification of the yellow ligament
  • Uncontrolled psychiatric disorder, epilepsy, or dementia
  • Positive test for Hepatitis B surface antigen or HBV-DNA (using real-time PCR). Positive Hepatitis B core antibody is permitted if HBV-DNA PCR is negative and the patient remains on prophylaxis during study.
  • Positive test for Hepatitis C virus antibody, unless Hepatitis C PCR is negative.
  • Positive test for HIV antibody, unless undetectable HIV RNA > 6 months and CD4 within normal limits per institutional standard.
  • Patients considered unqualified to participate in the study by the Principal Investigator or co-Investigator

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Non-Randomized
  • Interventional Model: Sequential Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: Cohort 1
Cohort 1: 0.3 mg/kg of mogamulizumab every 12 weeks, for 2 total doses
Drug: Mogamulizumab
Cohort 1: 0.3 mg/kg of mogamulizumab every 12 weeks, for 2 total doses Cohort 2: 0.3 mg/kg of mogamulizumab every 6 weeks, for 4 total doses
Experimental: Cohort 2
Cohort 2: 0.3 mg/kg of mogamulizumab every 6 weeks, for 4 total doses
Drug: Mogamulizumab
Cohort 1: 0.3 mg/kg of mogamulizumab every 12 weeks, for 2 total doses Cohort 2: 0.3 mg/kg of mogamulizumab every 6 weeks, for 4 total doses

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Minimum dose and schedule of mogamulizumab to reduce the proviral load by ≥75%
Time Frame: 6 months from baseline
To define the minimum efficacious dose and schedule of mogamulizumab to reduce the proviral load by ≥75% by pre-emptive treatment of HTLV-1 carriers with a limited course of mogamulizumab. The minimum efficacious dose will maintain ≥75% reduction in PVL from baseline levels for a minimum 6 months post completion of preemptive treatment with a limited course of mogamulizumab.
6 months from baseline

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Memorial Sloan Kettering Cancer Center

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Principal Investigator: Steven Horwitz, MD, Memorial Sloan Kettering Cancer Center

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

Helpful Links

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
November 15, 2024

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
November 15, 2029

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
November 15, 2029

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
November 18, 2024

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
November 18, 2024

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
November 20, 2024

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
March 5, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
March 3, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
March 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • 21-486

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

YES

IPD Plan Description

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.

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

Yes

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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