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TBTC Study 26 PK: Rifapentine Pharmacokinetics in Children During Treatment of Latent TB Infection

Not Applicable
Completed
Conditions
Tuberculosis
Registration Number
NCT00164450
Lead Sponsor
Centers for Disease Control and Prevention
Brief 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 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

Recruitment & Eligibility

Status
COMPLETED
Sex
All
Target Recruitment
230
Inclusion Criteria
  1. 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.
  2. 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.

Exclusion Criteria
  • None

Study & Design

Study Type
INTERVENTIONAL
Study Design
PARALLEL
Primary Outcome Measures
NameTimeMethod
Determine whether rifapentine exposure (level 24 hours after drug ingestion) is equivalent in young children receiving weight-based dosing to adults receiving 900 mg.24 hours after drug ingestion
Secondary Outcome Measures
NameTimeMethod
Correlate estimated rifapentine exposure with toxicity in young children receiving rifapentine and isoniazid for latent tuberculosis infection.During the three months of taking rifapentine
Validate the accuracy of estimated rifapentine exposure with pediatric rifapentine dose based on weight.24 hours after drug ingestion
Determine estimated drug bioavailability in pediatric subjects (ages 2 to < 12 years) given higher mg/kg doses of rifapentine.24 hours after drug ingestion
Determine the association in adults between polymorphisms of MDR1 genotype (P-glycoprotein) and rifapentine estimated exposure.at the time of blood draw
Determine the frequency of lower antitubercular drug concentrations in adults with acetylator status determined by N-acetyltransferase genotypes and of rifapentine by C24 and by MDR1 genotypes.at the time of blood draw

Trial Locations

Locations (24)

University of Southern California Medical Center

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Los Angeles, California, United States

Emory University School of Medicine

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Atlanta, Georgia, United States

University of California at San Diego

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San Diego, California, United States

University of California, San Francisco

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San Francisco, California, United States

New Jersey School of Medicine

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Newark, New Jersey, United States

Seattle-King County Health Department

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Seattle, Washington, United States

Boston University Medical Center

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Boston, Massachusetts, United States

Johns Hopkins University School of Medicine

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Baltimore, Maryland, United States

Audie L. Murphy VA Hospital

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San Antonio, Texas, United States

Duke University Medical Center

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Durham, North Carolina, United States

Central Arkansas Veterans Health System

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Little Rock, Arkansas, United States

University of British Columbia

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Vancouver, British Columbia, Canada

University of North Texas Health Science Center

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Fort Worth, Texas, United States

Denver Public Health Department

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Denver, Colorado, United States

Northwestern University School of Medicine

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Chicago, Illinois, United States

Veterans Administration Tennessee Valley Health Care System

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Nashville, Tennessee, United States

University of Manitoba

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Winnepeg, Manitoba, Canada

Agencia de Salut Publica

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Barcelona, Spain

Houston Veterans Administration Medical Center

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Houston, Texas, United States

Montreal Chest Institute

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Montreal, Quebec, Canada

Hines Veterans Administration Medical Center

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Hines, Illinois, United States

Hopital Universitario Clementino Fraga Filho

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Rio de Janeiro, Brazil

Washington DC Veterans Administration Medical Center

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Washington, District of Columbia, United States

Columbia University

πŸ‡ΊπŸ‡Έ

New York, New York, United States

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