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Latent TuberculosisPhase 1/2NCT03730181

Tuberculosis Clinical Trials Consortium Study 35

A Phase 1/2 study testing Rifapentine and Isoniazid in people with Latent Tuberculosis, run by Centers for Disease Control and Prevention at 1 site in South Africa.

Completed

Finished. The study has ended and is not enrolling. Results may be posted on the official record.

Official record
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Trial summary

Hypotheses: Rifapentine (given as water-dispersible monolayer and/or fixed dose combination with isoniazid) dosing in HIV-infected and uninfected children ≤ 12 years of age with latent TB infection (LTBI) or with exposure to Mycobacterium tuberculosis (M. Read more about this study

Who is it for?
Ages Up to 12 years
Conditions the study is for
Latent Tuberculosis
What is being tested?
Rifapentine and Isoniazid
Type of treatment
Pill or oral medicine
Could I receive a placebo?
No, everyone receives an active treatment
How many people
69 participants
Where
1 siteSouth Africa
Study dates
12 Nov 2019to 15 May 2025
Phase
Phase 1/2
Are there results?
Yes, posted in the registrySummary in the doctors' view

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 Up to 12 years
  • All sexes
  • No healthy volunteers
  • Child

Who may be able to join

  • Aged 0 - 12 years
  • Documented close (household or other close exposure) for at least an average 4 hours a day over the past 6 months to a bacteriologically confirmed adult (18 years or older) source case with pulmonary TB. The adult TB source case should have confirmed drug sensitive (sputum culture confirmed or XPERT MTB/Rif [Cepheid] positive TB and without any evidence of drug resistance, i.e., at least XPERT MTB/Rif rifampicin susceptible or an alternative molecular or phenotypic test indicating rifampicin susceptible M. tb) OR:
  • Evidence of M. tb infection (positive TST ≥ 10 mm in HIV-uninfected and TST ≥ 5 mm in HIV-infected participants or a positive commercial interferon-gamma release assay, as defined by the manufacturer)
  • Confirmed HIV status:
  • HIV status will be confirmed by DNA PCR and Plasma HIV-RNA if the participant is <18 months of age.
  • In participants ≥18 month of age HIV-ELISA testing will be completed. If any HIV test is positive in a child participant, regardless of age, the test result needs to be confirmed with a second HIV test, using HIV DNA or RNA PCR, from an independent sample.
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  • HIV-infected participants should be on an ART regimen for at least 12 weeks prior to enrolment and should be clinically stable before entering the study, regardless of CD 4 count and HIV viral load. While on study, participants must be on an efavirenz- or raltegravir-based ART regimen which should have been given for at least 14 days prior to enrolment.
  • Caregiver (parent or legal guardian) gives written informed consent and assent from the child where applicable
  • Weight > 2.5 kg but < 40 kg

Who cannot join

  • Active TB disease (evidenced by: symptoms suggestive of TB, or suggestive findings on clinical examination, or suggestive chest radiographic findings, or positive mycobacterial culture/molecular TB tests -if culture/molecular testing was clinically indicated and was completed-, or currently on TB treatment for active disease).
  • Any documented drug resistant TB (DR TB) in an identified adult source case, defined as rifampicin resistance on Xpert or any other relevant approved molecular test, or phenotypic evidence of rifampicin resistance.
  • Receipt of a once-daily isoniazid regimen for > 30 days which was given for at least 14 consecutive days in the 30 days prior to enrolment.
  • Hb < 10 mg/dl
  • Weight for age z score below 2 or severe clinical malnutrition
  • Known allergy or hypersensitivity to isoniazid or rifapentine
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  • Documented hepatic disorder including > 5 fold elevated upper limit of normal (ULN) ALT and/or bilirubin
  • Lansky play score < 50
  • Documentation of Hepatitis A or B infection
  • Female adolescents who have reached menarche will not be eligible.

Trial locations and contacts

1 site in 1 country.

South Africa1 site
  • Desmond Tutu TB Center, University of Stellenbosch

    Stellenbosch

Other trials in South Africa

About this study

Official title: Phase I/II Dose Finding and Safety Study of Rifapentine and Isoniazid in HIV-Infected and HIV-Uninfected Children With Latent Tuberculosis Infection

Hypotheses: Rifapentine (given as water-dispersible monolayer and/or fixed dose combination with isoniazid) dosing in HIV-infected and uninfected children ≤ 12 years of age with latent TB infection (LTBI) or with exposure to Mycobacterium tuberculosis (M. tuberculosis) will require higher mg/kg rifapentine dosing than adults to achieve adult- exposures which are correlated with efficacy in trials of TB prevention. Investigators further hypothesize that rifapentine will be safe and well-tolerated in HIV-infected and uninfected children who require treatment for LTBI.

Read the detailed description

Design: Tuberculosis Trials Consortium Study 35 (TBTC S35) is a Phase I/II, open-label, single arm, exposure-controlled dose finding study using an adaptive design. S35 will evaluate the pharmacokinetics (PK), safety and tolerability of rifapentine given in a new fixed dose combination once-weekly, in combination with isoniazid for 12 weeks, in HIV-infected and HIV-uninfected children aged 0-12 years in whom LTBI treatment is indicated. The study utilizes a modified age de-escalation approach given the extensive PK and safety data already available in children older than 2 years of age. The protocol allows for parallel enrolment of children into cohorts 1 and 2, simultaneously, using a predetermined modeled initial dose for each cohort, separately. Similarly, cohorts 3 and 4 will be enrolled in parallel, using modeled doses for each cohort, based on data from cohorts 1 and 2 and historical data from TBTC trials.

Sample Size: Approximately 72 participants will be required to ensure a minimum number of 60 evaluable participants.

Participants will be enrolled in 4 age cohorts:

Cohort 1: ≥ 4 to ≤ 12 years Cohort 2: ≥ 24 months to < 4 years Cohort 3: ≥ 12 to < 24 months Cohort 4: 0 to <12 months

There will be a minimum of 12 participants each in cohorts 1 and 2, and 18 participants each in cohorts 3 and 4, to allow for 36 participants in the age group below 2 years, given the importance of developmental pharmacology in this youngest age group (Table 1) and the lack of historical data in this age group. Cohorts 3 and 4 will be enrolled once week 1 PK and safety data is available in cohorts 1 and 2.

Up to 18 HIV-infected children overall will be enrolled, with a target of 12 HIV-infected children overall. It is expected that most HIV-infected children will be > 3 years of age given current international recommendations regarding the use of efavirenz in children in international settings, where the study will be conducted. However, it is expected that integrase inhibitors (e.g. raltegravir) would become more routinely available during the study period, allowing younger HIV-infected children to also be enrolled on study.

Population: HIV-infected and uninfected children aged 0-12 years who could benefit from chemotherapy for LTBI to prevent the development of active tuberculosis, who have documented close recent exposure to a bacteriologically positive drug sensitive adult pulmonary TB source case, or who have proof of M. tuberculosis infection. HIV-infected children will be established on anti-retroviral therapy for at least 12 weeks prior to enrolment.

Sites:

TBTC Site 33, Desmond Tutu TB Centre, Department of Paediatrics and Child Health, Stellenbosch University, South Africa TBTC Site 34, Baragwaneth, Perinatal HIV Research Unit (PHRU), Wits Health Consortium, Soweto, Johannesburg, South Africa

Study Duration: Child participants will be on study for a total of 24 weeks, including a 12-week rifapentine and isoniazid dosing period, with an additional follow-up period of 12 weeks. The overall study accrual period will be approximately 18 months and the total study duration will be approximately 36 months.

Description of Agent or Intervention:

Participants will receive 12 once-weekly doses of water-dispersible rifapentine and isoniazid; the initial rifapentine dose in each age cohort will be determined based on historical population models and will be adjusted as data become available in paediatric cohorts in this study. Cohorts 1 and 2 will open up with a pre-selected modeled dose. Dose selection for cohorts 3 and 4 will be modeled from data emerging from cohorts 1 and 2 and historical data. Doses in cohorts will be adjusted as required based on interim PK and safety analyses. Isoniazid will be given at doses of up to 25 mg/kg, once weekly, in combination with pyridoxine (Vitamin B6) 25 mg/kg.

Being tested
Rifapentine, Isoniazid
Medical subject headings
Latent Tuberculosis

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • RifapentineDrug

    Also called Priftin®, RPT (common abbreviation)

    Rifapentine. Initial dose will be 25mg/kg. Based on interim analysis, this may be adjusted throughout the study to achieve target exposures. The standalone water-dispersible rifapentine tablet may be used to adjust the rifapentine doses, if needed.

  • IsoniazidDrug

    Also called INH

    Isoniazid. 25mg/kg

Study groups in NCT03730181
Study groupRoleWhat they receive
Single Arm Rifapentine and IsoniazidExperimentalSingle arm, open label and exposure-controlled. Intervention is rifapentine given in a new fixed dose combination once-weekly, in combination with isoniazid for 12 weeks, in HIV-infected and HIV-uninfected children aged 0-12 years in whom LTBI treatment is indicated. The protocol allows for parallel enrolment of children into cohorts 1 and 2, simultaneously, using a predetermined modeled initial dose for each cohort, separately. Similarly, cohorts 3 and 4 will be enrolled in parallel, using modeled doses for each cohort, based on data from cohorts 1 and 2 and historical data from TBTC trials.
Receives: Drug: Rifapentine; Drug: Isoniazid

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Rifapentine Pharmacokinetic Exposure (AUC) Following Weekly 3HP Administration

    Rifapentine exposure was assessed using population pharmacokinetic analysis incorporating pharmacokinetic samples collected during the 12-week treatment period. Reported AUC values are model-derived estimates from the overall pharmacokinetic analysis. The target median AUC was 522 mg·h/L, with an acceptable range of 392-914 mg·h/L.

    Measured: During the 12-week treatment period, based on pharmacokinetic samples collected during study treatment

Secondary outcomes (1)
  1. Incidence of Grade ≥3 Adverse Events Related to Study Treatment

    Safety and tolerability of 3HP were assessed through clinical and laboratory adverse event monitoring during treatment and follow-up.

    Measured: 12-week treatment period and 24-week follow-up

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted5 Nov 2018
  2. Study start12 Nov 2019
  3. Primary completion15 Dec 2024
  4. Study completion15 May 2025

Resources

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 1/2
Primary purpose
Prevention
Allocation
Not applicable
Intervention model
Single group
Masking
None (open label)
Enrolment
69 participants (actual)
IDs, dates and publications
ClinicalTrials.gov ID
NCT03730181
Sponsor's protocol ID
6993
Status last verified
Jun 2026
First submitted
12 Oct 2018
Last updated
24 Jul 2026
Data monitoring committee
Yes
FDA-regulated drug
Yes
FDA-regulated device
No

Publications

  • Madzime RJ, van der Laan L, du Toit S, Barnabas S, Courtney I, Brown NE, Savic R, Solans BP, Dixon MG, Tsirizani L, Denti P, Boyd R, Hesseling AC; TBTC Study 35 team. Dolutegravir concentrations in children receiving 3-month weekly isoniazid and rifapentine (3HP) for tuberculosis prevention. Microbiol Spectr. 2026 Feb 3;14(2):e0330325. doi: 10.1128/spectrum.03303-25. Epub 2026 Jan 8.

    PubMed 41504451

Questions about this trial

What is this clinical trial studying?

A Phase 1/2 study testing Rifapentine and Isoniazid in people with Latent Tuberculosis, run by Centers for Disease Control and Prevention at 1 site in South Africa.

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 9 inclusion and 10 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 24 Jul 2026. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 1 site in South Africa. 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 combined 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.

Phase 2 studies give the treatment to a larger group to see whether it has the intended effect and to keep checking safety.

Not every study follows the same path, and some studies (observational studies, device studies) have no phase.

Are results available for this study?

Yes. Results are posted in the registry (first posted 24 Jul 2026). A summary is in the For doctors view, and the full results are on ClinicalTrials.gov.

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?

Rifapentine Pharmacokinetic Exposure (AUC) Following Weekly 3HP Administration (time frame: During the 12-week treatment period, based on pharmacokinetic samples collected during study treatment). It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT03730181, which also lists 1 linked publication.

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 24 Jul 2026.

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