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High-Dose Isoniazid Among Adult Patients With Different Genetic Variants of INH-Resistant Tuberculosis (TB)

The Early Bactericidal Activity of High-Dose or Standard-Dose Isoniazid Among Adult Participants With Isoniazid-Resistant or Drug-Sensitive Tuberculosis

Status
Completed
Phases
Phase 2
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT01936831
Enrollment
282
Registered
2013-09-06
Start date
2014-08-13
Completion date
2021-10-06
Last updated
2023-02-17

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Tuberculosis

Brief summary

Isoniazid (INH) is a drug commonly used to treat tuberculosis (TB) worldwide. Sometimes, the bacteria that cause TB can become resistant to INH. Resistance means that bacteria have adapted to a drug and are able to live in the presence of the drug. When TB becomes resistant to INH, INH does not work as well at fighting the bacteria. This study treated people with INH-resistant TB with different doses of INH to see if INH can still fight the bacteria if the dose is increased. We evaluated how well the drug works at higher doses for participants who have resistant TB as well as how well the drug works at regular doses for participants who have TB that is not resistant. The study also evaluated the safety and tolerability of the different doses of INH. Tolerability is how well people can put up with the side effects of a drug. Using increased doses of INH to treat TB that is resistant to INH is experimental and has not been approved by regulatory authorities. While there is some evidence that this approach will work, this has not yet been proven.

Detailed description

A5312 was a two-stage, two-step, phase IIa, open-label, randomized clinical trial among adult participants with sputum smear positive pulmonary TB evaluating the early bacterial activity (EBA). No study drug was administered under Step 1. Data collected in Step 1: (a) determined eligibility to Step 2, and (b) allowed characterization of INH MICs in three groups. Groups 1, 2, and 3 consist of participants infected with TB with inhA mutations, with drug susceptible TB (DS-TB), and with TB with katG resistance-conferring mutations, respectively. Participants enrolled to Step 2 received the study drug, INH, which was given with vitamin B6 \>=25 mg daily, by mouth. During both stages, participants in Group 1 who met Step 2 entry criteria were randomized to receive 5, 10, or 15 mg/kg of INH daily for 7 days. During Stage 2, participants in Group 2 who met Step 2 entry criteria received 5 mg/kg of INH daily for 7 days. Under protocol version 3.0 during Stage 2, participants in Group 3 who met Step 2 entry criteria were randomized to receive 15 or 20 mg/kg of INH daily for 7 days. After completion of 7 days of INH alone, participants were referred to begin standard anti-TB chemotherapy according to local guidelines. In Step 2, prior to initiation of treatment, sputum was collected for quantitative culture on solid medium (for colony forming units (CFU) for Groups 1 and 2 only) and liquid medium (for determination of time to positivity (TTP) for all groups). Sixteen-hour sputum collections were performed daily during INH treatment, as per standard early bacterial activity (EBA) methodology. Sampling for PK analysis was performed at steady state on Day 6 (±1). Safety and tolerability were monitored via clinical evaluations throughout the study and through scheduled laboratory evaluations. The study consisted of two stages, as follows: Stage 1-Pilot study to ensure feasibility: The goal of Stage 1 was to demonstrate feasibility, not treatment efficacy. Participants were recruited at a single clinical site. All eligible participants entered Step 1 of the study (determination of INH resistance, measurement of INH minimum inhibitory concentrations (MIC)). Among Group 1 participants who met the Step 2 entry criteria, 15 participants were randomized 1:1:1 to receive 5, 10, or 15 mg/kg daily of INH for 7 days with evaluations performed as described above. Stage 1 completed March 26, 2015. A total of 15 Group 1, 44 Group 2, and 12 Group 3 participants were enrolled in Step 1 only during Stage 1. These participants did not receive study treatment. They provided sputum samples for MIC determination. Stage 2-Main study: During Stage 2, Group 1 participants who met Step 2 entry criteria were randomized 1:1:1 to receive 5, 10, or 15 mg/kg of INH daily for 7 days. Group 2 participants who met Step 2 entry criteria were enrolled and received INH at a dose of 5 mg/kg daily. Group 3 participants who met Step 2 entry criteria were enrolled and randomized 1:1 to receive INH at a dose of 15 or 20 mg/kg daily. In Stage 1, Group 1 participants who did not meet Step 2 entry criteria, all Group 2 participants and all Group 3 participants were referred to a local TB program for treatment. In Stage 2, Group 1, 2 and 3 participants who did not meet Step 2 entry criteria, were referred to a local TB program for treatment. Protocol Versions: Key differences in protocol versions include the following: * Study entry criteria were changed from protocol versions 1.0 to 2.0 * No longer excluded individuals for antiretroviral therapy use * Exclusion of individuals with any MDR-TB treatment with second-line anti-TB drugs was relaxed to exclude only those with more than 7 cumulative days of use. * Protocol version 2.0 allowed additional sites to enroll participants. * Under protocol versions 1.0 and 2.0, eligible individuals in Group 1 and Group 2 could enroll in Step 1 and Step 2, and eligible individuals in Group 3 could be enrolled in Step 1 only. Under protocol version 3.0, eligible individuals in Group 3 could enroll in Step 1 and Step 2. * Early bactericidal activity was described using both solid culture CFU and liquid culture TTP under protocol versions 1.0 and 2.0. Under protocol version 3.0, early bactericidal activity was measured by liquid culture TTP only. * There were technical difficulties with measuring the isoniazid minimum inhibitory concentration using 1% agar solution for participants enrolled under protocols versions 1.0 and 2.0. For protocol version 3.0, the Thermo Fisher MYCOTB Sensititre plate was substituted to overcome the technical difficulties.

Interventions

DRUGIsoniazid

INH was available in 100 mg tablets. INH was administered orally daily in the morning on an empty stomach. Doses of INH were given according to the weight bands and by cohort.

DIETARY_SUPPLEMENTVitamin B6

Vitamin B6 was administered at \>= 25 mg daily and was obtained locally for use by study participants.

Sponsors

National Institute of Allergy and Infectious Diseases (NIAID)
CollaboratorNIH
Advancing Clinical Therapeutics Globally for HIV/AIDS and Other Infections
Lead SponsorNETWORK

Study design

Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
NONE

Eligibility

Sex/Gender
ALL
Age
18 Years to 65 Years
Healthy volunteers
No

Inclusion criteria

for Step 1: * New or recurrent pulmonary TB with sputum positive for acid-fast bacilli on direct microscopy of at least grade 1+ (International Union Against Tuberculosis and Lung Disease \[IUATLD\] scale) at the study laboratory on at least one pre-treatment sputum sample within 14 days prior to entry. * Infected with an M. tuberculosis strain for which Hain GenoType MTBDRplus genotype, performed at the study laboratory within 14 days prior to study entry, reveals one of the following results for INH susceptibility testing: * inhA promoter or functional mutation only (Group 1 participants, eligible for Steps 1 and 2) * No mutations in the inhA or katG genes (Group 2 participants, eligible for Step 1 and, during Stage 2 of the study, also eligible for Step 2) * katG mutation with or without an inhA mutation (Group 3 participants, eligible for Step 1 and, during Stage 2 of the study, also eligible for Step 2) * Ability and willingness of the participant or legal guardian/representative to provide informed consent. Inclusion Criteria for Step 2: * Entry into Step 1. * During Stage 1 of the protocol: inhA promoter or functional mutation only (Group 1). * During Stage 2 of the protocol: inhA promoter or functional mutation only (Group 1) OR mutations in neither inhA nor katG genes (Group 2) or mutation in the katG gene, with or without mutations in inhA promoter or functional genes (Group 3). * Body weight: 40 kg to 90 kg, inclusive. * Laboratory values obtained within 30 days prior to entry: * Absolute neutrophil count (ANC) \>=750 cells/mm\^3 * Hemoglobin \>= 7.4 g/dL * Platelet count \>= 50,000/mm\^3 * Aspartate aminotransferase (AST) and alanine aminotransferase (ALT) \<=3 X upper limit of normal (ULN) * Total bilirubin \<=2.5 X ULN * HIV infection status must be documented as either absent or present, as defined below: Absence of HIV-1 infection within 30 days prior to Step 2 entry OR HIV-1 infection at any time prior to Step 2 entry. * For HIV-positive candidates only: CD4+ cell count of \>=50 cells/mm\^3, performed within 7 days prior to entry at a DAIDS-approved laboratory * For females of reproductive potential, negative serum or urine pregnancy test within 7 days prior to entry. Female participants who are participating in sexual activity that could lead to pregnancy must agree to use one reliable non-hormonal method of contraception (condoms or an IUD), or another method (diaphragm or cervical cap) if it is approved by the national regulatory authority and used according to package insert, while receiving study medications. * Willingness to be hospitalized for a minimum of 9 consecutive days. * Ability to produce an overnight sputum sample of sufficient quality and quantity.

Exclusion criteria

for Step 1: -There are no

Design outcomes

Primary

MeasureTime frameDescription
Daily Change in log10 Colony-forming Unit (CFU)Measured at baseline and Day 7Negative daily change in log10 CFU indicate decreases in bacterial burden over the 7 day period. Defined as EBA0-7(CFU) = \[Day 7 log10 CFU per mL - baseline log10 CFU per mL\]/7. The baseline measure is the mean of the pre-entry visit and entry visit sputum colony counts.
Daily Change in Time to Positivity (TTP)Measured at baseline and Day 7The time to positivity (TTP) measures growth of mycobacterium tuberculosis using MGIT assay in hours. Higher values of daily change in TTP indicate greater decrease in bacterial burden over the 7 day period and is therefore better. Daily change is defined as EBA0-7(TTP) = \[Day 7 TTP - Baseline TTP\]/7. Baseline is the mean of the pre-entry visit and entry visit TTPs.
INH PK Parameter Area Under the Concentration Time Curve (AUC 0-24 Hours)Intensive INH PK samples collected on Day 6 of INH initiation at sample times pre-dose, 0.5h, 1h, 2h, 4h, 6h, 8h, 12h and 24h post-dose.AUC 0-24h defines area under the concentration-time curve over the period of 24 hours post-dose, estimated through non-compartmental methods using the linear trapezoidal rule.
Number of Participants With Grade 2 or Higher Drug-related Adverse Clinical or Laboratory EventsMeasured from entry through Day 21Post-entry, all new diagnoses, signs/symptoms and laboratory events of ≥Grade 2 that were assessed by the site as drug related. The DAIDS AE Grading Table (V1.0) and EAE Manual (V2.0) were used.

Secondary

MeasureTime frameDescription
INH PK Parameter Minimum Plasma Concentration (Cmin)Intensive INH PK samples collected on Day 6 of INH initiation at sample times pre-dose, 0.5h, 1h, 2h, 4h, 6h, 8h, 12h and 24h post-dose.Cmin defines minimum concentration observed over the 24 hours of the INH dosing interval.
INH PK Parameter Maximum Plasma Concentration (Cmax)Intensive INH PK samples collected on Day 6 of INH initiation at sample times pre-dose, 0.5h, 1h, 2h, 4h, 6h, 8h, 12h and 24h post-dose.Cmax defines maximum concentration observed over the 24 hours of the INH dosing interval.
INH Minimum Inhibitory Concentration (MIC) Against M. Tuberculosis IsolatesDay 0MIC are determined by phenotypic drug susceptibility testing (DST) based on spot sputum collected at Step 1 Day 0. For group 3 participants shown, MIC was tested using Thermofisher Sensititre MYCOTB plates.
Proportions of Participants Estimated to Have a Drop in log10 CFU/mL at or Above 0.65 log10 CFU/mL.From baseline through day 7Proportions of participants obtained through simulation using the estimated model who have a drop in log10 CFU/mL at or above the threshold of 0.65 log10 CFU/mL; 0.65 is half the drop in log10 CFU/mL observed in participants with DS-TB (Group 2) on day 7. A total of 10000 simulated pseudo-participants per arm were used based on data from the study participants. The NAT2 genotype distribution was based only on Group 1 and 2 participants since NAT2 genotype data was not available for Group 3. The simulations were run repeatedly. The point estimate of the proportion was based on the median proportion of the pseudo-individuals across the repeated simulations and the 90% confidence interval used the 5th and 95th percentiles of the proportion across the repeated simulations.
Daily Change in log10 CFU Measured by Early- (EBA0-2) and Late-phase (EBA2-7) Individual-based Parameter Estimates From Nonlinear ModelsAt baseline, day 2, and day 7Negative daily change in log10 CFU indicate decreases in bacterial burden over the time period. The mean CFU are estimated using all values by fitting a biphasic regression models for each participant. The daily change for the first two days of treatment was calculated as EBA0-2 (CFU)= \[Day 2 log10 CFU per mL - baseline log10 CFU per mL\]/2. The daily change from day 2 to day 7 was calculated as EBA2-7 (CFU)= \[Day 7 log10 CFU per mL - Day 2 log10 CFU per mL\]/5. Baseline is the average of pre-entry and entry visits.
Daily Change in TTP Measured by Early- (EBA0-2) and Late-phase (EBA2-7) Individual-based Parameter Estimates From Nonlinear ModelsAt baseline, day 2, and day 7The time to positivity (TTP) measures growth of mycobacterium tuberculosis using MGIT assay in hours. Higher values of daily change in TTP indicate greater decrease in bacterial burden over the time period and is therefore better. The mean log transformed TTP are estimated using all values by fitting a biphasic regression models for each participant. The daily change over the first two days of treatment is calculated as EBA0-2 (TTP)= \[Day 2 TTP - baseline TTP\]/2. The daily change from Day 2 to Day 7 is calculated as EBA2-7 (TTP)= \[Day 7 TTP - Day 2 TTP\]/5. Baseline is the average of pre-evaluation and entry visits.
EBA Measured by Individual-based Parameter Estimates From Linear or Nonlinear Models When the Number of Phases Differs Between Every Dosing CohortFrom baseline through day 7Both TTPs and log10 CFU from the pre-evaluation and entry visits averaged and treated as the baseline TTP and log10 CFU for each participant. This outcome was included for analysis if the number of phases differed between every dosing cohort. Since the number of phases did not differ between dosing cohorts, this outcome was not measured.
Mean EBA Measured by Ratio of the Following Areas: Numerator = AUC of Observed log10 CFU Over 7 Days and Denominator = Baseline log10 CFU for Every Dosing Cohort in Groups 1 and 2From baseline through day 7This approach utilizes the area between baseline CFU per mL and the CFU curve for each participant, as measured using the trapezoidal rule. This outcome was included for analysis if the number of phases differed between every dosing cohort. Since the number of phases did not differ between dosing cohorts, this outcome was not measured.

Countries

Haiti, South Africa

Participant flow

Recruitment details

No drug was administered under Step 1. Data collected in Step 1 determined eligibility to Step 2. Participants in Steps 1 and 2 were enrolled from August 2014 to September 2021 at 2 non-US clinical research sites.

Participants by arm

ArmCount
Group 1: 5mg Cohort
Group 1 participants had an M. tuberculosis strain with an inhA mutation only. 5 mg cohort received Isoniazid 5 mg/kg daily plus vitamin B6 \>=25 mg daily for 7 days
13
Group 1: 10mg Cohort
Group 1 participants had an M. tuberculosis strain with an inhA mutation only. 10 mg cohort received Isoniazid 10 mg/kg daily plus vitamin B6 \>=25 mg daily for 7 days
14
Group 1: 15mg Cohort
Group 1 participants had an M. tuberculosis strain with an inhA mutation only. 15 mg cohort received Isoniazid 15 mg/kg daily plus vitamin B6 \>=25 mg daily for 7 days
16
Group 2: 5mg Cohort
Group 2 participants had an M. tuberculosis strain with neither inhA nor katG mutations. All Group 2 participants received Isoniazid 5 mg/kg daily plus vitamin B6 \>=25 mg daily for 7 days
16
Group 3: 15mg Cohort
Group 3 participants had an M. tuberculosis strain with a katG mutation with or without an inhA mutation. 15mg cohort received Isoniazid 15 mg/kg daily plus vitamin B6 \>=25 mg daily for 7 days
11
Group 3: 20mg Cohort
Group 3 participants had an M. tuberculosis strain with a katG mutation with or without an inhA mutation. 20mg cohort received Isoniazid 20 mg/kg daily plus vitamin B6 \>=25 mg daily for 7 days
10
Step 1 Group 1
Group 1 participants had an M. tuberculosis isolate with an inhA resistance mutation. This group only includes participants who did not proceed to step 2.
67
Step 1 Group 2
Group 2 participants had drug susceptible TB and harbored neither inhA nor kat G resistance mutations. This group only includes participants who did not proceed to step 2.
69
Step 1 Group 3
Group 3 participants had an M. tuberculosis isolate with a katG resistance mutation. This group only includes participants who did not proceed to step 2.
66
Total282

Withdrawals & dropouts

PeriodReasonFG000FG001FG002FG003FG004FG005FG006FG007FG008
Step 2: Arm RandomizationWithdrawal by Subject000001000

Baseline characteristics

CharacteristicGroup 1: 15mg CohortGroup 2: 5mg CohortGroup 3: 15mg CohortGroup 3: 20mg CohortStep 1 Group 1Step 1 Group 2Group 1: 5mg CohortTotalStep 1 Group 3Group 1: 10mg Cohort
Age, Continuous34 years30 years36 years39 years36 years32 years31 years35 years35 years32 years
BMI18.5 kg/m^218.0 kg/m^219.3 kg/m^217.6 kg/m^218.1 kg/m^218.1 kg/m^217.7 kg/m^2
HIV Status
Living with HIV
4 Participants3 Participants2 Participants2 Participants2 Participants16 Participants3 Participants
HIV Status
Living without HIV
12 Participants13 Participants9 Participants8 Participants11 Participants64 Participants11 Participants
Karnofsky Score80 units on a scale90 units on a scale80 units on a scale90 units on a scale90 units on a scale90 units on a scale90 units on a scale
Race/Ethnicity, Customized
Black Non-Hispanic
16 Participants15 Participants10 Participants10 Participants66 Participants69 Participants13 Participants279 Participants66 Participants14 Participants
Race/Ethnicity, Customized
White Non-Hispanic
0 Participants1 Participants1 Participants0 Participants1 Participants0 Participants0 Participants3 Participants0 Participants0 Participants
Region of Enrollment
Haiti
0 Participants0 Participants7 Participants5 Participants0 Participants0 Participants0 Participants14 Participants2 Participants0 Participants
Region of Enrollment
South Africa
16 Participants16 Participants4 Participants5 Participants67 Participants69 Participants13 Participants268 Participants64 Participants14 Participants
Sex: Female, Male
Female
6 Participants4 Participants3 Participants3 Participants26 Participants27 Participants3 Participants97 Participants22 Participants3 Participants
Sex: Female, Male
Male
10 Participants12 Participants8 Participants7 Participants41 Participants42 Participants10 Participants185 Participants44 Participants11 Participants

Adverse events

Event typeEG000
affected / at risk
EG001
affected / at risk
EG002
affected / at risk
EG003
affected / at risk
EG004
affected / at risk
EG005
affected / at risk
deaths
Total, all-cause mortality
0 / 130 / 140 / 160 / 160 / 110 / 10
other
Total, other adverse events
12 / 1314 / 1415 / 1616 / 1611 / 1110 / 10
serious
Total, serious adverse events
0 / 131 / 140 / 161 / 160 / 110 / 10

Outcome results

Primary

Daily Change in log10 Colony-forming Unit (CFU)

Negative daily change in log10 CFU indicate decreases in bacterial burden over the 7 day period. Defined as EBA0-7(CFU) = \[Day 7 log10 CFU per mL - baseline log10 CFU per mL\]/7. The baseline measure is the mean of the pre-entry visit and entry visit sputum colony counts.

Time frame: Measured at baseline and Day 7

Population: Participants who took at least one dose of study treatment in Step 2 in Groups 1 and 2. CFU was not collected for Group 3. Participants who had missing Baseline or Day 7 CFU counts were not included.

ArmMeasureValue (MEAN)Dispersion
Group 1: 5mg CohortDaily Change in log10 Colony-forming Unit (CFU)-0.06 log10 CFU per mL sputum per dayStandard Deviation 0.14
Group 1: 10mg CohortDaily Change in log10 Colony-forming Unit (CFU)-0.18 log10 CFU per mL sputum per dayStandard Deviation 0.12
Group 1: 15mg CohortDaily Change in log10 Colony-forming Unit (CFU)-0.21 log10 CFU per mL sputum per dayStandard Deviation 0.15
Group 2: 5mg CohortDaily Change in log10 Colony-forming Unit (CFU)-0.15 log10 CFU per mL sputum per dayStandard Deviation 0.11
Primary

Daily Change in Time to Positivity (TTP)

The time to positivity (TTP) measures growth of mycobacterium tuberculosis using MGIT assay in hours. Higher values of daily change in TTP indicate greater decrease in bacterial burden over the 7 day period and is therefore better. Daily change is defined as EBA0-7(TTP) = \[Day 7 TTP - Baseline TTP\]/7. Baseline is the mean of the pre-entry visit and entry visit TTPs.

Time frame: Measured at baseline and Day 7

Population: Participants who took at least one dose of study treatment in Step 2. Participants who had missing Baseline or Day 7 TTP counts were not included.

ArmMeasureValue (MEAN)Dispersion
Group 1: 5mg CohortDaily Change in Time to Positivity (TTP)3 hours per dayStandard Deviation 8
Group 1: 10mg CohortDaily Change in Time to Positivity (TTP)8 hours per dayStandard Deviation 6
Group 1: 15mg CohortDaily Change in Time to Positivity (TTP)10 hours per dayStandard Deviation 8
Group 2: 5mg CohortDaily Change in Time to Positivity (TTP)10 hours per dayStandard Deviation 4
Group 3: 15mg CohortDaily Change in Time to Positivity (TTP)2.0 hours per dayStandard Deviation 7.9
Group 3: 20mg CohortDaily Change in Time to Positivity (TTP)4.6 hours per dayStandard Deviation 7.9
Primary

INH PK Parameter Area Under the Concentration Time Curve (AUC 0-24 Hours)

AUC 0-24h defines area under the concentration-time curve over the period of 24 hours post-dose, estimated through non-compartmental methods using the linear trapezoidal rule.

Time frame: Intensive INH PK samples collected on Day 6 of INH initiation at sample times pre-dose, 0.5h, 1h, 2h, 4h, 6h, 8h, 12h and 24h post-dose.

Population: Participants in each treatment dose arm with intensive PK results in Step 2.

ArmMeasureValue (MEDIAN)
Group 1: 5mg CohortINH PK Parameter Area Under the Concentration Time Curve (AUC 0-24 Hours)14.05 ug*hr/mL
Group 1: 10mg CohortINH PK Parameter Area Under the Concentration Time Curve (AUC 0-24 Hours)53.08 ug*hr/mL
Group 1: 15mg CohortINH PK Parameter Area Under the Concentration Time Curve (AUC 0-24 Hours)50.24 ug*hr/mL
Group 2: 5mg CohortINH PK Parameter Area Under the Concentration Time Curve (AUC 0-24 Hours)10.47 ug*hr/mL
Group 3: 15mg CohortINH PK Parameter Area Under the Concentration Time Curve (AUC 0-24 Hours)54.13 ug*hr/mL
Group 3: 20mg CohortINH PK Parameter Area Under the Concentration Time Curve (AUC 0-24 Hours)70.54 ug*hr/mL
Primary

Number of Participants With Grade 2 or Higher Drug-related Adverse Clinical or Laboratory Events

Post-entry, all new diagnoses, signs/symptoms and laboratory events of ≥Grade 2 that were assessed by the site as drug related. The DAIDS AE Grading Table (V1.0) and EAE Manual (V2.0) were used.

Time frame: Measured from entry through Day 21

Population: Participants who took at least one dose of study treatment in Step 2.

ArmMeasureValue (COUNT_OF_PARTICIPANTS)
Group 1: 5mg CohortNumber of Participants With Grade 2 or Higher Drug-related Adverse Clinical or Laboratory Events0 Participants
Group 1: 10mg CohortNumber of Participants With Grade 2 or Higher Drug-related Adverse Clinical or Laboratory Events4 Participants
Group 1: 15mg CohortNumber of Participants With Grade 2 or Higher Drug-related Adverse Clinical or Laboratory Events0 Participants
Group 2: 5mg CohortNumber of Participants With Grade 2 or Higher Drug-related Adverse Clinical or Laboratory Events1 Participants
Group 3: 15mg CohortNumber of Participants With Grade 2 or Higher Drug-related Adverse Clinical or Laboratory Events1 Participants
Group 3: 20mg CohortNumber of Participants With Grade 2 or Higher Drug-related Adverse Clinical or Laboratory Events0 Participants
Secondary

Daily Change in log10 CFU Measured by Early- (EBA0-2) and Late-phase (EBA2-7) Individual-based Parameter Estimates From Nonlinear Models

Negative daily change in log10 CFU indicate decreases in bacterial burden over the time period. The mean CFU are estimated using all values by fitting a biphasic regression models for each participant. The daily change for the first two days of treatment was calculated as EBA0-2 (CFU)= \[Day 2 log10 CFU per mL - baseline log10 CFU per mL\]/2. The daily change from day 2 to day 7 was calculated as EBA2-7 (CFU)= \[Day 7 log10 CFU per mL - Day 2 log10 CFU per mL\]/5. Baseline is the average of pre-entry and entry visits.

Time frame: At baseline, day 2, and day 7

Population: Four participants were excluded from the analysis due to missing CFU values in Group 1-INH 10 mg (2), Group 1-INH 15mg (1), and Group 2 (1). CFU was not collected for Group 3.

ArmMeasureGroupValue (MEAN)Dispersion
Group 1: 5mg CohortDaily Change in log10 CFU Measured by Early- (EBA0-2) and Late-phase (EBA2-7) Individual-based Parameter Estimates From Nonlinear ModelsEBA(0-2)-0.23 log10 CFU per mL sputum per dayStandard Deviation 0.3
Group 1: 5mg CohortDaily Change in log10 CFU Measured by Early- (EBA0-2) and Late-phase (EBA2-7) Individual-based Parameter Estimates From Nonlinear ModelsEBA(2-7)-0.01 log10 CFU per mL sputum per dayStandard Deviation 0.15
Group 1: 10mg CohortDaily Change in log10 CFU Measured by Early- (EBA0-2) and Late-phase (EBA2-7) Individual-based Parameter Estimates From Nonlinear ModelsEBA(2-7)-0.17 log10 CFU per mL sputum per dayStandard Deviation 0.13
Group 1: 10mg CohortDaily Change in log10 CFU Measured by Early- (EBA0-2) and Late-phase (EBA2-7) Individual-based Parameter Estimates From Nonlinear ModelsEBA(0-2)-0.17 log10 CFU per mL sputum per dayStandard Deviation 0.22
Group 1: 15mg CohortDaily Change in log10 CFU Measured by Early- (EBA0-2) and Late-phase (EBA2-7) Individual-based Parameter Estimates From Nonlinear ModelsEBA(0-2)-0.13 log10 CFU per mL sputum per dayStandard Deviation 0.39
Group 1: 15mg CohortDaily Change in log10 CFU Measured by Early- (EBA0-2) and Late-phase (EBA2-7) Individual-based Parameter Estimates From Nonlinear ModelsEBA(2-7)-0.25 log10 CFU per mL sputum per dayStandard Deviation 0.17
Group 2: 5mg CohortDaily Change in log10 CFU Measured by Early- (EBA0-2) and Late-phase (EBA2-7) Individual-based Parameter Estimates From Nonlinear ModelsEBA(0-2)-0.41 log10 CFU per mL sputum per dayStandard Deviation 0.33
Group 2: 5mg CohortDaily Change in log10 CFU Measured by Early- (EBA0-2) and Late-phase (EBA2-7) Individual-based Parameter Estimates From Nonlinear ModelsEBA(2-7)-0.07 log10 CFU per mL sputum per dayStandard Deviation 0.19
Secondary

Daily Change in TTP Measured by Early- (EBA0-2) and Late-phase (EBA2-7) Individual-based Parameter Estimates From Nonlinear Models

The time to positivity (TTP) measures growth of mycobacterium tuberculosis using MGIT assay in hours. Higher values of daily change in TTP indicate greater decrease in bacterial burden over the time period and is therefore better. The mean log transformed TTP are estimated using all values by fitting a biphasic regression models for each participant. The daily change over the first two days of treatment is calculated as EBA0-2 (TTP)= \[Day 2 TTP - baseline TTP\]/2. The daily change from Day 2 to Day 7 is calculated as EBA2-7 (TTP)= \[Day 7 TTP - Day 2 TTP\]/5. Baseline is the average of pre-evaluation and entry visits.

Time frame: At baseline, day 2, and day 7

Population: All available TTP results were used.

ArmMeasureGroupValue (MEAN)Dispersion
Group 1: 5mg CohortDaily Change in TTP Measured by Early- (EBA0-2) and Late-phase (EBA2-7) Individual-based Parameter Estimates From Nonlinear ModelsEBA(0-2)7.78 hours per dayStandard Deviation 17.22
Group 1: 5mg CohortDaily Change in TTP Measured by Early- (EBA0-2) and Late-phase (EBA2-7) Individual-based Parameter Estimates From Nonlinear ModelsEBA(2-7)1.77 hours per dayStandard Deviation 9.61
Group 1: 10mg CohortDaily Change in TTP Measured by Early- (EBA0-2) and Late-phase (EBA2-7) Individual-based Parameter Estimates From Nonlinear ModelsEBA(0-2)11.03 hours per dayStandard Deviation 6.4
Group 1: 10mg CohortDaily Change in TTP Measured by Early- (EBA0-2) and Late-phase (EBA2-7) Individual-based Parameter Estimates From Nonlinear ModelsEBA(2-7)5.45 hours per dayStandard Deviation 7.39
Group 1: 15mg CohortDaily Change in TTP Measured by Early- (EBA0-2) and Late-phase (EBA2-7) Individual-based Parameter Estimates From Nonlinear ModelsEBA(2-7)12.01 hours per dayStandard Deviation 8.29
Group 1: 15mg CohortDaily Change in TTP Measured by Early- (EBA0-2) and Late-phase (EBA2-7) Individual-based Parameter Estimates From Nonlinear ModelsEBA(0-2)7.35 hours per dayStandard Deviation 14.73
Group 2: 5mg CohortDaily Change in TTP Measured by Early- (EBA0-2) and Late-phase (EBA2-7) Individual-based Parameter Estimates From Nonlinear ModelsEBA(0-2)22.39 hours per dayStandard Deviation 11.44
Group 2: 5mg CohortDaily Change in TTP Measured by Early- (EBA0-2) and Late-phase (EBA2-7) Individual-based Parameter Estimates From Nonlinear ModelsEBA(2-7)5.09 hours per dayStandard Deviation 6.43
Group 3: 15mg CohortDaily Change in TTP Measured by Early- (EBA0-2) and Late-phase (EBA2-7) Individual-based Parameter Estimates From Nonlinear ModelsEBA(0-2)2.91 hours per dayStandard Deviation 3.57
Group 3: 15mg CohortDaily Change in TTP Measured by Early- (EBA0-2) and Late-phase (EBA2-7) Individual-based Parameter Estimates From Nonlinear ModelsEBA(2-7)2.69 hours per dayStandard Deviation 12.21
Group 3: 20mg CohortDaily Change in TTP Measured by Early- (EBA0-2) and Late-phase (EBA2-7) Individual-based Parameter Estimates From Nonlinear ModelsEBA(2-7)5.45 hours per dayStandard Deviation 8.36
Group 3: 20mg CohortDaily Change in TTP Measured by Early- (EBA0-2) and Late-phase (EBA2-7) Individual-based Parameter Estimates From Nonlinear ModelsEBA(0-2)-1.36 hours per dayStandard Deviation 7.59
Secondary

EBA Measured by Individual-based Parameter Estimates From Linear or Nonlinear Models When the Number of Phases Differs Between Every Dosing Cohort

Both TTPs and log10 CFU from the pre-evaluation and entry visits averaged and treated as the baseline TTP and log10 CFU for each participant. This outcome was included for analysis if the number of phases differed between every dosing cohort. Since the number of phases did not differ between dosing cohorts, this outcome was not measured.

Time frame: From baseline through day 7

Population: This outcome was not measured.

Secondary

INH Minimum Inhibitory Concentration (MIC) Against M. Tuberculosis Isolates

MIC are determined by phenotypic drug susceptibility testing (DST) based on spot sputum collected at Step 1 Day 0. For group 3 participants shown, MIC was tested using Thermofisher Sensititre MYCOTB plates.

Time frame: Day 0

Population: Step 1 participants in Group 3 for whom MIC results were available and tested using Thermofisher Sensititre MYCOTB plates. MIC was not done using Thermofisher Sensititre MYCOTB plates for participants enrolled under versions 1.0 and 2.0 of the protocol (including all Group 1 and 2 participants and many Group 3 participants). Three Group 3 Version 3 participants had missing MIC results. Note: Participants were not yet randomized to a treatment in Step 1 so all Group 3 participants are combined.

ArmMeasureGroupValue (COUNT_OF_PARTICIPANTS)
Group 1: 5mg CohortINH Minimum Inhibitory Concentration (MIC) Against M. Tuberculosis Isolates0.5 μg/mL0 Participants
Group 1: 5mg CohortINH Minimum Inhibitory Concentration (MIC) Against M. Tuberculosis Isolates1 μg/mL1 Participants
Group 1: 5mg CohortINH Minimum Inhibitory Concentration (MIC) Against M. Tuberculosis Isolates0.03 μg/mL1 Participants
Group 1: 5mg CohortINH Minimum Inhibitory Concentration (MIC) Against M. Tuberculosis Isolates0.06 μg/mL0 Participants
Group 1: 5mg CohortINH Minimum Inhibitory Concentration (MIC) Against M. Tuberculosis Isolates0.12 μg/mL0 Participants
Group 1: 5mg CohortINH Minimum Inhibitory Concentration (MIC) Against M. Tuberculosis Isolates0.25 μg/mL0 Participants
Group 1: 5mg CohortINH Minimum Inhibitory Concentration (MIC) Against M. Tuberculosis Isolates2 μg/mL4 Participants
Group 1: 5mg CohortINH Minimum Inhibitory Concentration (MIC) Against M. Tuberculosis Isolates4 μg/mL9 Participants
Group 1: 5mg CohortINH Minimum Inhibitory Concentration (MIC) Against M. Tuberculosis Isolates>4 μg/mL3 Participants
Secondary

INH PK Parameter Maximum Plasma Concentration (Cmax)

Cmax defines maximum concentration observed over the 24 hours of the INH dosing interval.

Time frame: Intensive INH PK samples collected on Day 6 of INH initiation at sample times pre-dose, 0.5h, 1h, 2h, 4h, 6h, 8h, 12h and 24h post-dose.

Population: Participants in each treatment dose arm with intensive PK results in Step 2.

ArmMeasureValue (MEDIAN)
Group 1: 5mg CohortINH PK Parameter Maximum Plasma Concentration (Cmax)5.26 ug/mL
Group 1: 10mg CohortINH PK Parameter Maximum Plasma Concentration (Cmax)10.4 ug/mL
Group 1: 15mg CohortINH PK Parameter Maximum Plasma Concentration (Cmax)15.1 ug/mL
Group 2: 5mg CohortINH PK Parameter Maximum Plasma Concentration (Cmax)4.55 ug/mL
Group 3: 15mg CohortINH PK Parameter Maximum Plasma Concentration (Cmax)15 ug/mL
Group 3: 20mg CohortINH PK Parameter Maximum Plasma Concentration (Cmax)22.15 ug/mL
Secondary

INH PK Parameter Minimum Plasma Concentration (Cmin)

Cmin defines minimum concentration observed over the 24 hours of the INH dosing interval.

Time frame: Intensive INH PK samples collected on Day 6 of INH initiation at sample times pre-dose, 0.5h, 1h, 2h, 4h, 6h, 8h, 12h and 24h post-dose.

Population: Participants in each treatment dose arm with intensive PK results in Step 2.

ArmMeasureValue (MEDIAN)
Group 1: 5mg CohortINH PK Parameter Minimum Plasma Concentration (Cmin)0.053 ug/mL
Group 1: 10mg CohortINH PK Parameter Minimum Plasma Concentration (Cmin)0.053 ug/mL
Group 1: 15mg CohortINH PK Parameter Minimum Plasma Concentration (Cmin)0.053 ug/mL
Group 2: 5mg CohortINH PK Parameter Minimum Plasma Concentration (Cmin)0.053 ug/mL
Group 3: 15mg CohortINH PK Parameter Minimum Plasma Concentration (Cmin)0.053 ug/mL
Group 3: 20mg CohortINH PK Parameter Minimum Plasma Concentration (Cmin)0.053 ug/mL
Secondary

Mean EBA Measured by Ratio of the Following Areas: Numerator = AUC of Observed log10 CFU Over 7 Days and Denominator = Baseline log10 CFU for Every Dosing Cohort in Groups 1 and 2

This approach utilizes the area between baseline CFU per mL and the CFU curve for each participant, as measured using the trapezoidal rule. This outcome was included for analysis if the number of phases differed between every dosing cohort. Since the number of phases did not differ between dosing cohorts, this outcome was not measured.

Time frame: From baseline through day 7

Population: This outcome was not measured.

Secondary

Proportions of Participants Estimated to Have a Drop in log10 CFU/mL at or Above 0.65 log10 CFU/mL.

Proportions of participants obtained through simulation using the estimated model who have a drop in log10 CFU/mL at or above the threshold of 0.65 log10 CFU/mL; 0.65 is half the drop in log10 CFU/mL observed in participants with DS-TB (Group 2) on day 7. A total of 10000 simulated pseudo-participants per arm were used based on data from the study participants. The NAT2 genotype distribution was based only on Group 1 and 2 participants since NAT2 genotype data was not available for Group 3. The simulations were run repeatedly. The point estimate of the proportion was based on the median proportion of the pseudo-individuals across the repeated simulations and the 90% confidence interval used the 5th and 95th percentiles of the proportion across the repeated simulations.

Time frame: From baseline through day 7

Population: Data from all participants were included in the modeling.

ArmMeasureValue (MEDIAN)
Group 1: 5mg CohortProportions of Participants Estimated to Have a Drop in log10 CFU/mL at or Above 0.65 log10 CFU/mL.0.17 proportion of simulated participants
Group 1: 10mg CohortProportions of Participants Estimated to Have a Drop in log10 CFU/mL at or Above 0.65 log10 CFU/mL.0.50 proportion of simulated participants
Group 1: 15mg CohortProportions of Participants Estimated to Have a Drop in log10 CFU/mL at or Above 0.65 log10 CFU/mL.0.64 proportion of simulated participants
Group 2: 5mg CohortProportions of Participants Estimated to Have a Drop in log10 CFU/mL at or Above 0.65 log10 CFU/mL.0.88 proportion of simulated participants
Group 3: 15mg CohortProportions of Participants Estimated to Have a Drop in log10 CFU/mL at or Above 0.65 log10 CFU/mL.0.01 proportion of simulated participants
Group 3: 20mg CohortProportions of Participants Estimated to Have a Drop in log10 CFU/mL at or Above 0.65 log10 CFU/mL.0.05 proportion of simulated participants

Source: ClinicalTrials.gov · Data processed: Feb 19, 2026