TuberculosisNCT00164450
TBTC Study 26 PK: Rifapentine Pharmacokinetics in Children During Treatment of Latent TB Infection
A study testing Isoniazid and Rifapentine in people with Tuberculosis, run by Centers for Disease Control and Prevention at 24 sites in 4 countries.
Trial summary
Compared to adults, children appear to require higher weight-based doses of rifapentine to acheive comparable drug levels. TBTC Study 26, a study of the effectiveness and tolerability of weekly rifapentine/isoniazid for three months versus daily isoniazid for nine months for the treatment of latent tuberculosis… Read more about this study
- Who is it for?
- Ages 2 years and older
- Conditions the study is for
- Tuberculosis
- What is being tested?
- Isoniazid and Rifapentine
- Type of treatment
- Pill or oral medicine
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 158 participants
- Where
- 24 sitesin 4 countries
- Study dates
- Sep 2005to Aug 2008
- Phase
- Interventional
- 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 2 years and older
- All sexes
- No healthy volunteers
- Child, Adult, Older adult
Who may be able to join
- Enrolled in TBTC Study 26 randomized to treatment with once weekly isoniazid and rifapentine:
- Child between the ages of 2 to less than 12 years for whom informed consent by a guardian and of assent (if applicable) have been obtained.
- Adult greater than age 18 for whom informed consent has been obtained.
- Willingness to undergo a blood phlebotomy 24 hours following dosing of isoniazid and rifapentine after receiving at least three once-weekly doses of rifapentine plus isoniazid.
- If as a result of a contact investigation, both a parent and child are enrolled in Study 26, both may be co-enrolled into the pharmacokinetic substudy with the adult serving as the control for the child. Preference will be given to a biologic parent of the same gender. If no eligible biologic parent is available for study, the next adult of the same gender and at the same TBTC site, who is substudy eligible, will serve as the adult control.
Who cannot join
- None
Trial locations and contacts
24 sites in 4 countries.
24 sites in 4 countries
United States19 sites
Emory University School of Medicine
Atlanta, Georgia, 30303
Johns Hopkins University School of Medicine
Baltimore, Maryland, 21231
Boston University Medical Center
Boston, Massachusetts, 02118
Northwestern University School of Medicine
Chicago, Illinois, 21231
Denver Public Health Department
Denver, Colorado, 80204
Duke University Medical Center
Durham, North Carolina, 27710
University of North Texas Health Science Center
Fort Worth, Texas, 76104
Hines Veterans Administration Medical Center
Hines, Illinois, 60141
Houston Veterans Administration Medical Center
Houston, Texas, 77030
Central Arkansas Veterans Health System
Little Rock, Arkansas, 72205
University of Southern California Medical Center
Los Angeles, California, 90033
Veterans Administration Tennessee Valley Health Care System
Nashville, Tennessee, 37232
Columbia University
New York, New York, 10032
New Jersey School of Medicine
Newark, New Jersey, 07103
Audie L. Murphy VA Hospital
San Antonio, Texas, 78284
University of California at San Diego
San Diego, California, 92103
University of California, San Francisco
San Francisco, California, 94110
Seattle-King County Health Department
Seattle, Washington, 98104
Washington DC Veterans Administration Medical Center
Washington D.C., District of Columbia, 20422
Canada3 sites
Montreal Chest Institute
Montreal, Quebec, H2X 2P4
University of British Columbia
Vancouver, British Columbia, V5Z 4R4
University of Manitoba
Winnepeg, Manitoba, R3A 1R8
Brazil1 site
Hopital Universitario Clementino Fraga Filho
Rio de Janeiro, 2194.590
About this study
Official title: TBTC Study 26 PK: Rifapentine Pharmacokinetics in Children Receiving Once Weekly Rifapentine and Isoniazid for the Treatment of Latent Tuberculosis Infection
Compared to adults, children appear to require higher weight-based doses of rifapentine to acheive comparable drug levels. TBTC Study 26, a study of the effectiveness and tolerability of weekly rifapentine/isoniazid for three months versus daily isoniazid for nine months for the treatment of latent tuberculosis infection, has been amended to include children ages 2-11 based on an initial single-dose study and pharmacokinetic modeling. Study 26PK evaluates the adequacy of the doses chosen for young children enrolled in Study 26 with a single blood draw, 24 hours after the third or subsequent weekly Study 26 dose of rifapentine and isoniazid. An adult control is enrolled for each child enrolled.
Read the detailed description
The pharmacokinetics of rifapentine have been studied in adults, adolescents (ages 12-15 years), and patients with hepatic dysfunction and HIV infection. However, there are no published data on the efficacy, safety or pharmacokinetics of rifapentine in children. This lack of data has precluded till now enrollment of children less than 12 years old in TBTC Study 26, a study of the effectiveness and tolerability of weekly rifapentine/isoniazid for three months versus daily isoniazid for nine months for the treatment of latent tuberculosis infection, a phase 3 treatment trial that will enroll 8000 persons with latent tuberculosis infection. A recently completed initial evaluation of rifapentine pharmacokinetics among children receiving a single dose of rifapentine demonstrated significantly lower exposures of rifapentine among children compared to adults, when children were given weight-based doses chosen to be comparable to a 600 mg oral dose in adults. This reduced exposure suggested that children require higher weight-based doses than adults and a model was constructed to estimate rifapentine doses in children that would result in exposures similar to the 900 mg dose used for adults in Study 26. Study 26 has been amended to include children ages 2-11 based on the initial single-dose study and pharmacokinetic modeling. The purpose of Study 26PK is to evaluate the adequacy of the doses chosen for young children who enrolled in Study 26.
Briefly, this study aims to:
- determine whether rifapentine exposure is equivalent in young children receiving weight-based dosing to adults receiving 900 mg.
- correlate rifapentine exposure with toxicity in young children
- validate accuracy of weight-based dosing in children
- determine rifapentine bioavailability in children
- determine association in adults between polymorphisms of MDR1 genotype and rifapentine exposure
- correlate isoniazid concentrations in adults with acetylator status
- Conditions
- Tuberculosis
- Being tested
- Isoniazid, Rifapentine
- Keywords
- tuberculosis, TB, pharmacokinetics, children
- Medical subject headings
- Tuberculosis
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
IsoniazidDrug
Also called INH
Isoniazid daily, oral, nine months
RifapentineDrug
Also called Priftin
Rifapentine plus Isoniazid taken orally, weekly, by direct observation for 12 weeks
| Study group | Role | What they receive |
|---|---|---|
| Daily Isoniazid for 9 months | Active comparator | Participants received isoniazid daily for 9 months for treatment of latent tuberculosis infection. Receives: Drug: Isoniazid |
| weekly Rifapentine plus Isoniazid for 12 weeks | Experimental | Participants received once-weekly rifapentine plus isoniazid for 12 weeks under direct observation for treatment of latent tuberculosis infection. Receives: Drug: Rifapentine |
What is being measured
The primary outcome is the main question the study is designed to answer.
Rifapentine Area Under the Plasma Concentration-Time Curve From Time Zero to Infinity, AUC0-inf
Rifapentine exposure was estimated in children and adults receiving once-weekly rifapentine plus isoniazid. A sparse sampling design used a plasma sample collected 24 hours after administration of study drugs.
Measured: 24 hours after study-drug administration; AUC0-inf estimated using a nonlinear mixed-effects pharmacokinetic model incorporating the 24-hour rifapentine concentration, C24.
Correlation Between Rifapentine C24 and AUC0-inf
Value represents the coefficient of determination (R-squared) for the relationship between rifapentine C24 and AUC0-inf.
Measured: 24 hours after study-drug administration
Secondary outcomes (1)
Rifapentine AUC0-inf by Tablet Administration Method in Children
Comparison of rifapentine AUC0-inf between participants receiving crushed and whole rifapentine tablets.
Measured: 24 hours after study-drug administration
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted14 Sep 2005 (estimated)
- Study startSep 2005
- Primary completionAug 2008
- Study completionAug 2008
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Posted resultsParticipant flow, outcome measures and adverse events reported by the sponsor.
- Other trials for TuberculosisStudies of the same condition, open and under way.
- 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 N/A
- Primary purpose
- Treatment
- Allocation
- Non-randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Enrolment
- 158 participants (actual)
Sponsor and investigators
- Lead sponsor
- Centers for Disease Control and Prevention
- Sponsor type
- US federal agency
- Collaborators
- US Department of Veterans Affairs
- Responsible party
- Sponsor
- Investigators
- Marc Weiner, MD, Study chair, VAMC and University of Texas Health Science Center San Antonio
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT00164450
- Sponsor's protocol ID
- CDC-NCHHSTP-4679
- Status last verified
- Jun 2026
- First submitted
- 10 Sep 2005
- Last updated
- 7 Jul 2026
- Results posted
- Yes, on ClinicalTrials.gov
- Data monitoring committee
- Yes
Study at a glance
From the registry record, last updated by the sponsor on 7 Jul 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- TBTC Study 26 PK: Rifapentine Pharmacokinetics in Children Receiving Once Weekly Rifapentine and Isoniazid for the Treatment of Latent Tuberculosis Infection
- ClinicalTrials.gov ID
- NCT00164450
- Acronym / sponsor ID
- CDC-NCHHSTP-4679
- Conditions
- Tuberculosis
- Keywords
- tuberculosis, TB, pharmacokinetics, children
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 158 participants (actual)
- Lead sponsor
- Centers for Disease Control and PreventionUS federal agency
- Collaborators
- US Department of Veterans Affairs
- Study start
- Sep 2005
- Primary completion
- Aug 2008 (actual)
- Study completion
- Aug 2008 (actual)
- First posted
- 14 Sep 2005 (estimated)
- Results
- Posted 7 Jul 2026
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Compared to adults, children appear to require higher weight-based doses of rifapentine to acheive comparable drug levels. TBTC Study 26, a study of the effectiveness and tolerability of weekly rifapentine/isoniazid for three months versus daily isoniazid for nine months for the treatment of latent tuberculosis infection, has been amended to include children ages 2-11 based on an initial single-dose study and pharmacokinetic modeling. Study 26PK evaluates the adequacy of the doses chosen for young children enrolled in Study 26 with a single blood draw, 24 hours after the third or subsequent weekly Study 26 dose of rifapentine and isoniazid. An adult control is enrolled for each child enrolled.
Detailed description
The pharmacokinetics of rifapentine have been studied in adults, adolescents (ages 12-15 years), and patients with hepatic dysfunction and HIV infection. However, there are no published data on the efficacy, safety or pharmacokinetics of rifapentine in children. This lack of data has precluded till now enrollment of children less than 12 years old in TBTC Study 26, a study of the effectiveness and tolerability of weekly rifapentine/isoniazid for three months versus daily isoniazid for nine months for the treatment of latent tuberculosis infection, a phase 3 treatment trial that will enroll 8000 persons with latent tuberculosis infection. A recently completed initial evaluation of rifapentine pharmacokinetics among children receiving a single dose of rifapentine demonstrated significantly lower exposures of rifapentine among children compared to adults, when children were given weight-based doses chosen to be comparable to a 600 mg oral dose in adults. This reduced exposure suggested that children require higher weight-based doses than adults and a model was constructed to estimate rifapentine doses in children that would result in exposures similar to the 900 mg dose used for adults in Study 26. Study 26 has been amended to include children ages 2-11 based on the initial single-dose study and pharmacokinetic modeling. The purpose of Study 26PK is to evaluate the adequacy of the doses chosen for young children who enrolled in Study 26.
Briefly, this study aims to:
- determine whether rifapentine exposure is equivalent in young children receiving weight-based dosing to adults receiving 900 mg.
- correlate rifapentine exposure with toxicity in young children
- validate accuracy of weight-based dosing in children
- determine rifapentine bioavailability in children
- determine association in adults between polymorphisms of MDR1 genotype and rifapentine exposure
- correlate isoniazid concentrations in adults with acetylator status
Study design
- Primary purpose
- Treatment
- Allocation
- Non-randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Daily Isoniazid for 9 months | Active comparator | Drug: IsoniazidParticipants received isoniazid daily for 9 months for treatment of latent tuberculosis infection. |
| weekly Rifapentine plus Isoniazid for 12 weeks | Experimental | Drug: RifapentineParticipants received once-weekly rifapentine plus isoniazid for 12 weeks under direct observation for treatment of latent tuberculosis infection. |
Who may qualify
- Ages
- 2 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Child, Adult, Older adult
Key inclusion criteria (5 listed)
- Enrolled in TBTC Study 26 randomized to treatment with once weekly isoniazid and rifapentine:
- Willingness to undergo a blood phlebotomy 24 hours following dosing of isoniazid and rifapentine after receiving at least three once-weekly doses of rifapentine plus isoniazid.
- If as a result of a contact investigation, both a parent and child are enrolled in Study 26, both may be co-enrolled into the pharmacokinetic substudy with the adult serving as the control for the child. Preference will be given to a biologic parent of the same gender. If no eligible biologic parent is available for study, the next adult of the same gender and at the same TBTC site, who is substudy eligible, will serve as the adult control.
Key exclusion criteria (1 listed)
- None
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 |
|---|---|---|
| IsoniazidAlso: INHIsoniazid daily, oral, nine months | Drug | Daily Isoniazid for 9 months |
| RifapentineAlso: PriftinRifapentine plus Isoniazid taken orally, weekly, by direct observation for 12 weeks | Drug | weekly Rifapentine plus Isoniazid for 12 weeks |
Primary outcome
Rifapentine Area Under the Plasma Concentration-Time Curve From Time Zero to Infinity, AUC0-inf
Time frame: 24 hours after study-drug administration; AUC0-inf estimated using a nonlinear mixed-effects pharmacokinetic model incorporating the 24-hour rifapentine concentration, C24.
Rifapentine exposure was estimated in children and adults receiving once-weekly rifapentine plus isoniazid. A sparse sampling design used a plasma sample collected 24 hours after administration of study drugs.
Correlation Between Rifapentine C24 and AUC0-inf
Time frame: 24 hours after study-drug administration
Value represents the coefficient of determination (R-squared) for the relationship between rifapentine C24 and AUC0-inf.
1 secondary outcome
Rifapentine AUC0-inf by Tablet Administration Method in Children
Time frame: 24 hours after study-drug administration
Results and safety
Loading the posted results from ClinicalTrials.gov…
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 7 Jul 2026.
- Posted resultsParticipant flow, baseline, all outcome measures and adverse events.
Related trials for Tuberculosis
RecruitingPhase 4
Short-term Antibiotic Therapy in Mycobacterium Avium Complex Pulmonary Disease
Mycobacterium Avium Complex Pulmonary Disease
RecruitingObservational study
Paradoxical Tuberculosis Reactions in Patients Without HIV Infection
Tuberculosis
Not yet recruitingPhase 2
Re-evaluating the Duration in Children of TB Treatment
Tuberculosis
RecruitingPhase 1/2
A Study of Daily Rifapentine Combined With Isoniazid (1HP) for Tuberculosis Prevention in Children Less Than 13 Years of Age With and Without HIV
Tuberculosis
Active, not recruitingPhase 3
Protecting Households On Exposure to Newly Diagnosed Index Multidrug-Resistant Tuberculosis Patients
Tuberculosis, MDR
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.
Marc Weiner, MD study chair
VAMC and University of Texas Health Science Center San Antonio
24 sites in 4 countries: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Isoniazid and Rifapentine in people with Tuberculosis, run by Centers for Disease Control and Prevention at 24 sites in 4 countries.
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 5 inclusion and 1 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 7 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 24 sites in United States, Canada, Brazil, Spain. 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.
Are results available for this study?
Yes. Results are posted in the registry (first posted 7 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 Area Under the Plasma Concentration-Time Curve From Time Zero to Infinity, AUC0-inf (time frame: 24 hours after study-drug administration; AUC0-inf estimated using a nonlinear mixed-effects pharmacokinetic model incorporating the 24-hour rifapentine concentration, C24.). The study lists 2 primary outcomes in all. 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 7 Jul 2026.