A phase 2, two-part, multicentre, open label, controlled, randomised clinical trial in adult participants with newly diagnosed, sputum-positive pulmonary drug-sensitive tuberculosis (DSTB). Assessing the Safety and Efficacy of TBAJ-587 as Part of a Combination Regimen in Newly Diagnosed, Drug-Sensitive, Sputum-Positive Pulmonary Tuberculosis
This is a phase 2, two-part, multicentre, open label, controlled, randomised clinical trial in adult participants with newly diagnosed, sputum-positive pulmonary DS-TB. The trial will be performed in two sequential parts, each part containing parallel treatment arms. Part A: Participants will be randomly assigned to one of two TBAJ-587 experimental regimens (TBA-587PaL, 100 mg or 200mg dose) or the active SOC control arm (HRZE:). Data from Part A will inform dose selection for Part B. Part B: Participants will be randomly assigned to one of three experimental regimens. The sequential design allows for an interim analysis (section 10.5) between Parts A and B to evaluate the safety and efficacy of lower and higher TBAJ-587 doses before progressing to Part B, where the selected dose will be used. TBAJ-587 may be replaced by a similar diarylquinolone compound if, based on the interim analysis - for scientific and/or safety reasons - determines that TBAJ-587 should not proceed into Part B. Should this occur, the protocol will be updated via submission of a formal protocol amendment. The active control arm included in Part A provides an internal benchmark to confirm that study procedures, microbiological methods, and clinical conduct perform as expected. Data generated from the Part A control arm will therefore serve as the primary internal reference for interpretation of Part B results. Therefore, there is no control arm in Part B. In addition, the bacteriological endpoints used in this study, including time to positivity (TTP) and related measures of early bactericidal activity, are well characterised for HRZE in the published literature. These established external data provide a robust contextual framework against which Part B outcomes can be interpreted, without the need for an additional concurrent control arm. This approach limits unnecessary exposure of participants to standard therapy beyond what is required to establish study validity, while allowing efficient evaluation of the selected investigational regimen in Part B.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
TREATMENT
Masking
NONE
Enrollment
135
TBAJ-587LD Tablet 50 mg 100 mg OD TBAJ-587HD Tablet 50 mg 200 mg OD TBAJ-587SD Tablet 50 mg Dose selected from Part A daily
Pretomanid Tablet 200 mg 200 mg OD
600 mg OD
TASK Brooklyn
Cape Town, Western Cape, South Africa
Rate of Change in Log10-Transformed Sputum Culture Time to Positivity From Baseline Through Week 8
Time to positivity is the time, measured in hours, required for a sputum culture to produce a positive result indicating detectable growth of Mycobacterium tuberculosis. The rate of change in log10-transformed time to positivity will be estimated for each treatment arm. Increasing time to positivity indicates a reduction in the viable mycobacterial load in sputum. Measured as change in log10(days).
Time frame: From baseline to the end of treatment at 8 weeks
Time to Sustained Sputum Culture Conversion From Baseline Through Week 8
Sustained sputum culture conversion is defined as the first of two consecutive negative sputum cultures, with no subsequent positive culture. Time to conversion will be calculated from baseline to the date of the first negative culture that meets this definition. Measured in days.
Time frame: From baseline to the end of treatment at 8 weeks
Percentage of Participants With Sustained Sputum Culture Conversion at Week 8
Sustained sputum culture conversion is defined as the first of two consecutive negative sputum cultures, with no subsequent positive culture. Participants who meet this definition by Week 8 will be included in the percentage. Measured as percentage of participants.
Time frame: At the end of treatment at 8 weeks
Percentage of Participants With Treatment-Emergent Adverse Events
A treatment-emergent adverse event (TEAE) is an adverse event that begins or worsens after the participant receives the first dose of study treatment. Participants experiencing one or more TEAEs will be counted once. Measured as percentage of participants.
Time frame: From enrollment through the final follow-up visit at Week 12
Percentage of Participants With Treatment-Emergent Adverse Events by Maximum Severity Grade as Assessed by CTCAE Version 5.0
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1 000 mg OD
H 75 mg, R 150 mg, Z 400 mg, E 275 mg fixed dose combination
30 mg OD
20 mg OD
The severity of each TEAE will be graded using the Common Terminology Criteria for Adverse Events (CTCAE) version 5.0. Grades range from 1 to 5: Grade 1 is mild, Grade 2 is moderate, Grade 3 is severe, Grade 4 is life-threatening and Grade 5 is death. Participants will be summarized according to their maximum recorded severity grade. Measured as percentage of participants.
Time frame: From enrollment through the final follow-up visit at Week 12
Percentage of Participants With Drug-Related Treatment-Emergent Adverse Events
A drug-related TEAE is a treatment-emergent adverse event assessed by the investigator as having a causal relationship to one or more study drugs. Participants experiencing one or more drug-related TEAEs will be counted once. Measured as percentage of participants.
Time frame: From enrollment through the final follow-up visit at Week 12
Percentage of Participants With Serious Treatment-Emerent Adverse Events
A serious TEAE is a treatment-emergent adverse event that results in death, is life-threatening, requires or prolongs inpatient hospitalization, results in persistent or significant disability or incapacity, causes a congenital anomaly or birth defect, or is considered another medically important event. Participants experiencing one or more serious TEAEs will be counted once. Measured as percentage of participants.
Time frame: From enrollment through the final follow-up visit at Week 12
Percentage of Participants With Treatment-Emergent Adverse Events Leading to Treatment Discontinuation
Participants who permanently discontinue one or more study drugs because of a TEAE will be included in this measure. Participants experiencing more than one qualifying event will be counted once. Measured as a percentage of participants.
Time frame: From enrollment through the final follow-up visit at Week 12
Percentage of Participants With Treatment-Emergent Adverse Events Leading to Death
Participants who die as a result of a TEAE will be included in this measure. Each participant will be counted once, regardless of the number of TEAEs contributing to the death. Measured as a percentage of participants.
Time frame: From enrollment through the final follow-up visit at Week 12
Percentage of Participants With Adverse Events of Special Interest
Adverse events of special interest are protocol-defined events that require specific monitoring because of their potential clinical importance in relation to the study drugs. Participants experiencing one or more adverse events of special interest will be counted once. Measured as a percentage of participants.
Time frame: From enrollment through the final follow-up visit at Week 12
Maximum Observed Plasma Concentration of Study Drugs and Their Metabolites
The maximum observed plasma concentration (Cmax) will be estimated using non-compartmental analysis for the applicable study drugs and metabolites in each treatment arm. These include TBAJ-587 and its metabolites M2, M3 and M12; pretomanid; linezolid; BTZ-043 and its metabolite M1; quabodepistat; and ganfeborole. No pharmacokinetic measurements will be performed in the HRZE control arm. Measured in ng/mL
Time frame: At Day 15 and Week 8 for participants in Part A and at Day 15 for participants in Part B
Minimum Observed Plasma Concentration of Study Drugs and Their Metabolites
The minimum observed plasma concentration (Cmin) will be estimated using non-compartmental analysis for the applicable study drugs and metabolites in each treatment arm. These include TBAJ-587 and its metabolites M2, M3 and M12; pretomanid; linezolid; BTZ-043 and its metabolite M1; quabodepistat; and ganfeborole. No pharmacokinetic measurements will be performed in the HRZE control arm. Measured as ng/mL.
Time frame: At Day 15 and Week 8 for participants in Part A and at Day 15 for participants in Part B
Time to Maximum Observed Plasma Concentration of Study Drugs and Their Metabolites
The time to maximum observed plasma concentration (Tmax) will be estimated using non-compartmental analysis for the applicable study drugs and metabolites in each treatment arm. These include TBAJ-587 and its metabolites M2, M3 and M12; pretomanid; linezolid; BTZ-043 and its metabolite M1; quabodepistat; and ganfeborole. No pharmacokinetic measurements will be performed in the HRZE control arm. Measured in hours.
Time frame: At Day 15 and Week 8 for participants in Part A and at Day 15 for participants in Part B
Area Under the Plasma Concentration-Time Curve From 0 to 24 Hours for Study Drugs and Their Metabolites
The area under the plasma concentration-time curve from 0 to 24 hours (AUC0-24) will be estimated using non-compartmental analysis for the applicable study drugs and metabolites in each treatment arm. These include TBAJ-587 and its metabolites M2, M3 and M12; pretomanid; linezolid; BTZ-043 and its metabolite M1; quabodepistat; and ganfeborole. No pharmacokinetic measurements will be performed in the HRZE control arm. Measured as ng-h/mL
Time frame: At Day 15 and Week 8 for participants in Part A and at Day 15 for participants in Part B