Dolutegravir Versus Dolutegravir in Combination With Tenofovir for the Treatment of HTLV-1 Infection (DOT-H)

May 29, 2026 updated by: Carlos Brites

Dolutegravir Versus Dolutegravir in Combination With Tenofovir for the Treatment of HTLV-1 Infection (DOT-H): an Open-label, Randomized, Controlled Study.

This phase 2b, open-label, randomized controlled trial evaluates the efficacy and safety of dolutegravir (DTG) alone versus dolutegravir combined with tenofovir disoproxil fumarate (TDF) in individuals with HTLV-1 infection and associated clinical manifestations. The primary objective is to compare changes in HTLV-1 proviral load at 24 and 48 weeks. Secondary outcomes include clinical, functional, immunological, and quality-of-life measures.

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.

Detailed Description

Human T-lymphotropic virus type 1 (HTLV-1) infection is a neglected condition associated with severe neurological and hematological diseases, including HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP). Currently, no effective antiviral therapy exists.

Preclinical and clinical data suggest that integrase inhibitors such as dolutegravir may reduce HTLV-1 proviral load. Additionally, combination therapy with tenofovir may enhance antiviral activity. This study builds on prior pilot data demonstrating partial virological response to DTG.

Participants will be randomized (1:1) to receive DTG alone or DTG plus TDF for 48 weeks. Outcomes will include virological, immunological, clinical, and patient-reported measures. The study aims to provide evidence for therapeutic strategies targeting HTLV-1.

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.
146

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

  • Brazil
    • Estado de Bahia
      • Salvador, Estado de Bahia, Brazil, 40110-060
        • Recruiting
        • Hospital Universitario Professor Edgard Santos
        • Contact:
        • Contact:
          • Delano Paiva

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:

  • Age equal or higher than 18 years
  • Confirmed HTLV-1 infection
  • Clinical manifestation atributable to HTLV-1
  • Ability to provide written informed consent

Exclusion Criteria:

  • Active HIV, HCV (RNA+), or HBV (HBsAg+) infection
  • Active tuberculosis
  • Recent corticosteroid use
  • Renal impairment (CrCl <50 mL/min)
  • Autoimmune diseases
  • Wheelchair-bound individuals
  • Active malignancy (except ATLL)
  • Substance abuse interfering with adherence
  • Any condition compromising safety

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: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Single

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.
Active Comparator: Dolutegravir
Dolutegravir 50 mg p.o. daily
Drug: Dolutegravir (DTG)
Active comparator will be DTG, 50 mg/day
Experimental: Combination therapy
Daily Dolutegravir 50 mg Daily Tenofovir 300 mg
Combination product: Combination of Dolutegravir + Tenofovir DF for treatment of HTLV-1 infection
In a previous study Dolutegravir was able to reduce HTLV-1 proviral load, but a few patients did not respond to therapy. We intend to use a combination of Dolutegravir + TDF to improve the response rate. There is no previous evidence on the use of such combination for treating HTLV-1 infection.

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
HTLV-1 Proviral Load
Time Frame: From baseline to the end of treatment at 48 weeks
Measurement of HTLV-1 Proviral Load by RT-PCR. Results will be expressed as copies/ml of whole blood
From baseline to the end of treatment at 48 weeks
Changes in Pain intensity (DN4 doleur scale)
Time Frame: Baeline, 24 and 48 weeks
Change in intensity of pain measured by DN4 doleur scale (0 to 10, with values >4 indicating neuropathic pain)
Baeline, 24 and 48 weeks
Changes in Spasticity
Time Frame: BL, 24 and 48 weeks
Changes in limbs spasticity, as measured by Ashworth scale. The Ashworth Scale uses a simple ordinal scale ranging from 0 to 4, where the highest values mean increased spasticity
BL, 24 and 48 weeks
Changes in muscle strenght
Time Frame: BL, 24 and 48 weeks
Evaluation of muscle strenght by Kendall Muscle Grading system (Kendal scale), which ranges from 0 to 10, with highest values indicating better muscle strenght
BL, 24 and 48 weeks
Changes in motor score scales
Time Frame: BL, 24, 48 weeks
Evaluation of changes in motor performance using the lower extremity motor score (LEMS) is a subscale of the International Standards for Neurological Classification of Spinal Cord Injury (ISNCSCI) that assesses lower extremity muscle strength.The score range is 0-5 for each of 5 key muscles (hip flexors, knee extensors, ankle dorsi-flexors, long toe extensors and ankle plantar flexors) of each leg, with a maximum score of 50 (the lower values indicates worse motor function)
BL, 24, 48 weeks

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Nocturia frequency
Time Frame: Baseline, 24 and 48 weeks
Nocturia frequency across the study
Baseline, 24 and 48 weeks
Cytokines levels
Time Frame: BL, 24 and 48 weeks
Measurement of levels of (Tumon Necrosis Factor-Alpha) TNF-alpha, IL-6, IL-2, IL-4, IL-10, Interferon γ-induced Protein (IP-10), Gamma-Interferon (Gamma-IFN), in picogram/cubic milimiter. Values may varies from undetectable levels to any detectable concentration, expressed in pg/mm3.
BL, 24 and 48 weeks
RAND 36-Item Health Survey
Time Frame: Baseline and at 48 weeks
The RAND Corporation Health-Related Quality of Life (RAND-36) domains are scored on a 0 to 100 range, so that a high score defines a more favorable health-related quality of life (HRQoL). The scale measure several domains of HRQoL.
Baseline and at 48 weeks

Other Outcome Measures

Other Outcome Measures

For clinical trials, a planned measurement described in the protocol that is used to determine the effect of an intervention/treatment on participants. For observational studies, a measurement or observation that is used to describe patterns of diseases or traits, or associations with exposures, risk factors, or treatment. Types of outcome measures include primary outcome measure and secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Frequency of Adverse events and Serious adverse events
Time Frame: baseline to 48 weeks
frequency of incident AE associated with the treatment drugs
baseline to 48 weeks
Quantification of HTLV-1
Time Frame: BL, at 24 and 48 weeks
To evaluate active replication of HTLV-1, we will measure the number of copies of Long Terminal Repeat (LTR) circles to detect HTLV-1 unintegrated proviral genome and HTLV-1 plasma RNA levels. Presence of any number of copies of LTR indicates ongoing active viral replication
BL, at 24 and 48 weeks
Measurement of Levels of sCD14 and sCD163
Time Frame: BL, 24 and 48 weeks
Levels of soluble cluster of diferentiation 14 (sCD14) and 163 (sCD14), expressed in ng/mL, will be measured to evaluate levels of monocytes´ activation across the trial. Higher levels indicate increased monocytes´ activation.
BL, 24 and 48 weeks

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.
Carlos Brites

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: Carlos Brites, MD, PhD, Hospital Universitário Professor Edgard Santos, Federal University of Bahia

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.

General Publications

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.
May 7, 2026

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.
May 1, 2028

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.
June 1, 2028

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).
April 8, 2026

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.
April 24, 2026

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.
April 29, 2026

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.
June 2, 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.
May 29, 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.
May 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.
  • FBAI-001/26

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

YES

IPD Plan Description

Anonimized clinical data can be shared with other researchers upon reasonable request

IPD Sharing Time Frame

IPD will be available from January 2029 to June 2029

IPD Sharing Access Criteria

Researchers with an approved protocol will be abel to access the databank upon reasonable request to the study PI

IPD Sharing Supporting Information Type

  • STUDY_PROTOCOL
  • SAP
  • ICF
  • ANALYTIC_CODE
  • CSR

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

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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