A Phase 2 interventional study of Rifampicin and Isoniazid in Tuberculosis, sponsored by University of Wisconsin, Madison. Not yet recruiting at 1 site in Peru. Open to participants aged 3 Months to 9 Years. Per ClinicalTrials.gov, last updated 2026-06-18.
Sponsored by University of Wisconsin, Madison · Phase 2, Interventional, and Treatment
Current tuberculosis (TB) treatment is effective (works well), but it takes a long time to cure TB. This study will evaluate if TB treatment with a higher dose of rifampicin, one of the TB medicines, and shorter TB treatment duration is as effective and safe as the standard, TB treatment (with the usual rifampicin dose and usual duration). This study hopes to find a better shorter treatment that works as well as the current treatment (standard of care). This could benefit children worldwide who are getting TB treatment.
Children 3 months to less than 10 years of age who have drug-susceptible TB (can be successfully treated with standard TB medicines) are eligible for this study.
This is a multi-arm open-label phase IIc trial with duration randomization, with a lead-in pharmacokinetics (PK) study. Children 3 months to less than 10 years of age with routinely diagnosed clinical or confirmed drug-susceptible TB will be screened and if eligible randomly assigned 1:1:1:1:1 to one of five arms (durations of TB treatment and control arm). Randomization will be stratified by age (3 months to less than 5 years of age vs 5 to less than 10 years of age).
A total of 200 participants will be enrolled in the main trial (Step 2), with 40 per study arm, with an additional 30 participants enrolled in a Lead-in PK study (Step 1).
Step 1 - Lead-in PK study participants will be on treatment for 8 weeks, complete their trial participation in up to 9 weeks, and will not contribute to the main trial endpoints.
Step 2 - Main trial participants will be on study for 48 weeks.
Primary Objective:
In children with drug-susceptible tuberculosis, with and without HIV:
Secondary Objectives:
The secondary objectives of the Lead-In PK study are to
The secondary objectives of the Main Study are to:
Confirmed or clinically diagnosed intrathoracic (pulmonary) and/or some forms of extrathoracic (extrapulmonary) drug-susceptible TB:
Confirmed intrathoracic (pulmonary) TB, based on chest radiograph and/or symptoms consistent with TB, and/or some forms of extrathoracic TB, with all of the following as determined by the site investigator:
Clinically diagnosed intrathoracic (pulmonary) TB, based on chest radiograph and/or symptoms consistent with TB, and/or some forms of extrathoracic TB, with all of the following as determined by the site investigator:
Exclusion Criteria:
N = 40, 8 weeks of odRHZE
Drug: Rifampicin · Drug: Isoniazid · Drug: Pyrazinamide · Drug: Ethambutol
N = 40, 8 weeks of odRHZE followed by 3 weeks of odRH
Drug: Rifampicin · Drug: Isoniazid · Drug: Pyrazinamide · Drug: Ethambutol
N = 40, 8 weeks of odRHZE followed by 6 weeks of odRH
Drug: Rifampicin · Drug: Isoniazid · Drug: Pyrazinamide · Drug: Ethambutol
N = 40, 8 weeks of odRHZE followed by 9 weeks of odRH
Drug: Rifampicin · Drug: Isoniazid · Drug: Pyrazinamide · Drug: Ethambutol
N = 40, 8 week of RHZ(E) followed by 9 weeks (5a - non-severe TB) or 16 weeks (5b - severe TB) of RH
Drug: Isoniazid · Drug: Pyrazinamide · Drug: Ethambutol · Drug: Rifampicin
N = 15 * Period 1 - odRIF Dosing Schedule A with HZE, PK sampling after 4 weeks followed by * Period 2 - odRIF Dosing Schedule B with HZE, PK sampling after 4 weeks Dosing schedules are by weight and age, with Schedule A a higher dose of RIF (totaling 250 - 1650mg) than Schedule B (totaling 200 - 1350mg)
Drug: Rifampicin · Drug: Isoniazid · Drug: Pyrazinamide · Drug: Ethambutol
N = 15 * Period 1 - odRIF Dosing Schedule B with HZE, PK sampling after 4 weeks followed by * Period 2 - odRIF Dosing Schedule A with HZE, PK sampling after 4 weeks Dosing schedules are by weight and age, with Schedule A a higher dose of RIF (totaling 250 - 1650mg) than Schedule B (totaling 200 - 1350mg)
Drug: Rifampicin · Drug: Isoniazid · Drug: Pyrazinamide · Drug: Ethambutol
odR for main trial determined from Lead-in PK study 75 mg tablet, and 150 or 300 mg capsule, dosed by weight and age
Also known as: two optimized-doses (odR) rifampicin
50 mg tablet, dosed by weight and age
Also known as: Isoniazid (H)
150 mg tablet, dosed by weight and age
Also known as: Pyrazinamide (Z)
100 mg tablet, dosed by weight and age
Also known as: Ethambutol (E)
standard of care and only the 75 mg tablet will be used
Also known as: standard dose rifampicin (R)
Step 2: Unfavorable TB treatment outcome
A participant has unfavorable treatment outcomes if they fail to meet either of the following criteria: * No treatment extension or re-treatment for TB at any time up through 48 weeks after randomization. * TB recurrence-free cure or Probable TB recurrence-free cure
Time frame: 48 weeks
Step 1: Safety measured by occurrence of Grade 3 to 5 Adverse Events after the first dose of study treatment by period in Lead-in PK study
Occurrence of at least one new or worsened Grade 3-5 Adverse Event (AE) after the first dose of study treatment by period.
Time frame: data collected from individual participants for 2 regimens of 4 weeks each, up to 8 weeks total
Step 1: Tolerability Measured by discontinuation of at least one drug in Lead-in PK study
Permanent discontinuation of at least one drug in the study regimen during each treatment period due to an AE of any grade that is either safety- or tolerability-related, death due to toxicity (probably/possibly/certainly) related to one or more of the study drugs, or participant/parent/guardian request.
Time frame: data collected from individual participants for 2 regimens of 4 weeks each, up to 8 weeks total
Step 1: Pharmacokinetics of optimized-dose rifampicin: (AUC0-24)
Area under the concentration time curve over 24 hours (AUC0-24)
Time frame: data collected at week 4 (and week 8) visit lead-in PK study; pre-dose (0 hour), 1, 2, 4, 8 and 24 hour post dose
Step 1: Pharmacokinetics of optimized-dose rifampicin: (Cmax)
Maximum concentration (Cmax)
Time frame: data collected at week 4 (and week 8) visit lead-in PK study; pre-dose (0 hour), 1, 2, 4, 8 and 24 hour post dose
Step 1: Acceptability of optimized-dose rifampicin summarized by participant count
Participant and/or parent/guardian responses to rifampicin acceptability question of "Overall, how did you/your child feel about taking this medicine?", scored on a likert scale from 1-5 with higher scores being more acceptable. Summarized by number of responses per score.
Time frame: baseline (at dose 1), week 4, week 8
Step 2: Safety Measured by Occurrence of at least one new or worsened Grade 3-5 adverse event after the first dose of study treatment in Main Trial
Occurrence of at least one new or worsened Grade 3-5 adverse event after the first dose of study treatment and during the 28 weeks following randomization, where 28 weeks is 4 weeks beyond the longest scheduled treatment duration of 24 weeks.
Time frame: up to 28 weeks
Step 2: Tolerability Measured by discontinuation of at least one drug in Main Trial
Permanent discontinuation of at least one drug in the study regimen prior to the end of the assigned treatment period due to an AE of any grade that is either safety- or tolerability-related, death due to toxicity (probably/possibly/certainly) related to one or more of the study drugs, or participant/parent/guardian request.
Time frame: up to 24 weeks
Step 2: Lung function post-TB treatment
The outcome of interest is abnormal lung function classified as having at least one of the following physiological findings based on results of spirometry and oscillometry (FEV1, forced expiratory volume in 1 second; FVC, forced vital capacity): * Obstructive lung disease: defined as FEV1, or FEV1/FVC of \<-1.64 z-score (z-score\<-1.64 = lower limit of normal, LLN) with normal FVC * Restrictive lung disease: defined as FVC \<-1.64 z-score with normal FEV1 * Mixed lung disease: defined as FEV1/FVC \<LLN; * Isolated small airway dysfunction: defined as oscillometry Area of reactance (AX) \>1.64 z-score and/or oscillometry peripheral airway resistance (R5-20) \>1.64 z-score with normal FEV1 on spirometry
Time frame: week 48
Step 2: Acceptability of optimized-dose rifampicin summarized by participant count
Participant and/or parent/guardian responses to rifampicin acceptability question of "Overall, how did you/your child feel about taking this medicine?", scored on a likert scale from 1-5 with higher scores being more acceptable. Summarized by number of responses per score.
Time frame: baseline (at dose 1), week 4, week 8
Step 2: Acceptability of overall TB treatment regimen summarized by participant count
Participant and/or parent/guardian responses to overall TB treatment regimen acceptability question of "In the last 4 weeks, how did you/your child feel about taking this TB treatment regimen, considering all of the TB medicines in the regimen together?", scored on a likert scale from 1-5 with higher scores being more acceptable. Summarized by number of responses per score.
Time frame: week 4, week 8
Plan to share: Yes
Supporting information: Study protocol, Sap, Icf
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University of Wisconsin, Madison