Ultra-Short Course Bedaquiline, Clofazimine, Pyrazinamide and Delamanid Versus Standard Therapy for Drug-Susceptible Tuberculosis

Phase 2Active Not RecruitingNCT05556746

Brigham and Women's Hospital94 enrolled

Overview

The PRESCIENT trial is a Phase IIc, open-label, randomized trial that compared a 12-week regimen of bedaquiline (BDQ), clofazimine (CFZ), pyrazinamide (PZA), and delamanid (DLM) with standard treatment for drug-susceptible pulmonary tuberculosis. Eligible participants were randomized in a 1:1 ratio to BDQ, CFZ, PZA, and DLM (BCZD) or standard anti-TB therapy. Randomization was stratified by presence of lung cavitation and HIV status. Participants were randomized to one of two arms: Arm 1 (Experimental): BDQ 200 mg for 12 weeks + PZA 1000 - 2000 mg (according to weight) for 12 weeks + CFZ 300 mg for 2 weeks, followed by 100 mg for 10 weeks + DLM 200 mg for 12 weeks, all given once daily. Arm 2 (Standard of Care): Rifampicin (RIF), Isoniazid (INH), Ethambutol (EMB) and Pyrazinamide (PZA) for 8 weeks, followed by RIF and INH for 18 weeks. Medications were given daily in fixed dose combinations at standard weight-based doses. Adherence was supported through automated reminders and monitored remotely in real time with Wisepill electronic adherence monitoring devices or with directly observed treatment. Participants in the experimental arm with evidence of poor clinical response were re-treated with standard TB therapy. The primary analysis is a superiority efficacy comparison of time to liquid culture conversion through 8 weeks in the experimental (BCZD) arm vs. the standard therapy (RHZE) arm. Participants had extended post-treatment follow up to evaluate clinical efficacy as a secondary composite outcome measure at 86 weeks after randomization (74 weeks after completion of experimental therapy, when most relapses are expected to occur). The other key secondary outcome is safety, measured as the proportion with new Grade 3 or higher adverse events; we focused on prolonged QT interval corrected using Fridericia's formula (QTcF) and hepatitis as adverse events of special interest. Through an efficient Phase IIc design, the PRESCIENT trial tested microbiological efficacy, evaluated safety, and detected treatment-emergent resistance with the ultra-short BCZD regimen. The PRESCIENT trial aimed to enroll 156 adults, but accrual was paused due to funding constraints and then permanently stopped per a Data and Safety Monitoring Board (DSMB) recommendation on December 12, 2025 due to both low conditional power (0.54%) for the primary outcome and a trend towards higher unfavorable outcomes in Arm 1 (BCZD).

Eligibility

Sex: ALLMin age: 18 Years

Medical Language ↔ Plain English

Inclusion Criteria: * Informed consent obtained and signed. * Pulmonary TB diagnosed by Xpert MTB/RIF, Xpert MTB/RIF Ultra, Line Probe Assay (LPA), or mycobacterial culture. * Sputum positive for acid fast bacilli (at least 1+ grade on the WHO scale). * Pulmonary TB diagnosed without known INH resistance (by LPA or Xpert MTB/XDR) and without known RIF resistance (by either LPA or Xpert). Note that phenotypic DST for INH resistance was done on screening cultures (using MGIT). If baseline molecular or phenotypic test results that become available after enrollment detect resistance to INH or RIF, the participant was a late exclusion from the study. * Newly diagnosed with TB and have a history of being untreated for at least 6 months after cure from a previous episode of TB. * For participants living with HIV, CD4+ cell count ≥200 cells/mm3, obtained within 30 days prior to study entry. Enrollment of participants living with HIV was limited to no more than 20% of the total study population. * For participants living with HIV, must be currently receiving or planning to initiate ART at or before study week 8. * Laboratory values at study screening: * Alanine aminotransferase (ALT) ≤3x the upper limit of normal (ULN) * Total bilirubin ≤2.5 x ULN * Creatinine ≤2 x ULN * Potassium ≥3.5 mEq/L, ≤5.5 mEq/L * Absolute neutrophil count (ANC) ≥650/mm3 * Hemoglobin ≥7.0g/dL * Platelet count ≥50,000/mm3 * For females of reproductive potential, negative serum or urine pregnancy test within 5 days prior to entry and willingness to use effective contraception for the duration of the study. Female participants who are not of reproductive potential must have documentation of menopause, hysterectomy, or bilateral oophorectomy or bilateral tubal ligation. Acceptable forms of contraception include: condoms, intrauterine device or intrauterine system, cervical cap with spermicide, diaphragm with spermicide. * The initial 25% of enrollment (n = 39) was restricted to participants with mild or moderate disease, defined as having sputum with higher Xpert MTB/RIF cycle threshold (Ct) values (\> 17 cycles) and the absence of extensive lung disease on chest X-ray (involvement of at least half of the area of the entire thoracic cavity). Thereafter, all eligible patients were offered participation without a pause in enrollment. Exclusion Criteria: * More than 5 days of treatment directed against active TB for the current TB episode preceding study entry. * Current extrapulmonary TB (e.g. neurological, skeletal, abdominal, or nodal), not including pleural TB, in the opinion of the site investigator. * Pregnant or breastfeeding. * Weight \<30kg. * Inability to take oral medications. * Current or planned use of any drug known to severely prolong the QTc interval, including, but not limited to: amiodarone, amitriptyline, chloroquine, chlorpromazine, cisapride, disopyramide, erthyromycin, moxifloxacin, procainamide, quinidine, or sotalol. * Current or planned use of one or more of the following HIV medications: HIV protease inhibitors, HIV non-nucleoside reverse transcriptase inhibitors, elvitegravir/cobicistat, or bictegravir. * Current or past use of clofazimine, bedaquiline or delamanid. * QTcF \>450ms for men or \>470 ms for women. * Current or history of known personal or family long QT syndrome. * Known allergy/sensitivity to components of study TB drugs or their formulation. Microbiologic confirmation of drug-susceptible TB is not always available at the time of enrollment. Enrolled individuals who are subsequently determined to meet either of the following criteria were classified as late exclusions and study treatment was discontinued. These participants were transitioned to routine care but requested to remain in study follow up for safety evaluations. A. Screening, baseline study, and Week 1 visit sputum cultures fail to grow M. tuberculosis. B. Resistance to RIF or INH is detected from baseline molecular or phenotypic testing results that become available after enrollment.

Outcomes

Primary Outcomes

Median Time to Stable Liquid Culture Conversion by Week 8

Culture conversion is defined as the first of two negative sputum cultures, consecutive or not, without an intervening positive culture, and/or visits wherein the participant is unable to produce sputum and has no signs or symptoms of active tuberculosis (TB).

Time frame: Measured through Week 8

Secondary Outcomes

Cumulative Probability of Experiencing Any Grade 3 or Higher Adverse Event (AE)

AEs include any occurrence that is new in onset or aggravated at least one-grade from baseline. AE's are graded according to the Division of AIDS Table for Grading the Severity of Adult and Pediatric Adverse Events (DAIDS AE Grading Table), Corrected Version 2.1, July 2017.

Time frame: Measured at Week 60

Cumulative Probability of Having a Favorable Composite Outcome

Favorable composite outcome is defined as no failure, relapse, or non-accidental death.

Time frame: Measured at Week 60

Proportion Who Prematurely Discontinue Treatment

Premature treatment discontinuation is defined as discontinuation other than due to violent death, natural disaster, or administrative censoring

Time frame: Measured at Week 12 in Arm 1 and Week 26 in Arm 2

Median Time to Stable Liquid Culture Conversion by Week 12

Time frame: Measured through Week 12

Mean Change in Skin Coloration Since TB Treatment Started at Weeks 8, 12, 16, 26, 60, and 86

Participants rate any change in skin color since TB treatment started on subjective 10-point numeric rating scale where 0=none, 10=worst possible change in coloration.

Time frame: Weeks 8, 12, 16, 26, 60, and 86

Mean Distress Related to Skin Coloration Since TB Treatment Started at Weeks 8, 12, 16, 26, 60, and 86

Participants rate distress from change in skin color since TB treatment started on subjective 10-point numeric rating scale where 0=none, 10=worst possible distress due to coloration.

Time frame: Weeks 8, 12, 16, 26, 60, and 86

Mean Change in QTcF From Baseline to Week 1, 2, 4, 8, 12, and 16

The QTcF is derived from ECG readings, which the sites conducted in triplicate (three ECGs 5-10 minutes apart). The mean of all measurements (up to 3) that are readable and available are used at each of baseline (screening visit), Week 1, Week 2, Week 4, Week 8, Week 12, and Week 16.

Time frame: Baseline (screening visit) and weeks 1, 2, 4, 8, 12, and 16

Mean Change in QTcF From Baseline to End of Treatment

The QTcF is derived from ECG readings, which the sites conducted in triplicate (three ECGs 5-10 minutes apart). The mean of all measurements (up to 3) that are readable and available are used at baseline (screening visit) and week 12 (Arm 1). ECG was not required at week 26 per the protocol thus the week 26 data was not collected.

Time frame: Measured at Week 12 in Arm 1 and Week 26 in Arm 2

Occurrence of Absolute QTcF >480 ms and ≤500 ms, and >500 ms

Time frame: Measured through Week 16

Occurrence of QTcF Change From Baseline of >30 ms and ≤60 ms, and >60 ms

The QTcF is derived from ECG readings, which the sites conducted in triplicate (three ECGs 5-10 minutes apart). The mean of all measurements (up to 3) that are readable and available are used at baseline (screening visit) and through week 16 in Arm 1 and Arm 2

Time frame: Measured through Week 16

Cumulative Probability of Having One or More Serious Adverse Events (SAEs)

An SAE is defined as any untoward medical occurrence that results in death; is life-threatening; requires inpatient hospitalization or prolongation of existing hospitalization; results in persistent or significant disability/incapacity; is a congenital anomaly/birth defect; is an important medical event that may not be immediately life-threatening or result in death or hospitalization but based upon appropriate medical judgment may jeopardize the participant and may require intervention to prevent one of the outcomes listed in the definition above.

Time frame: Measured through Week 86

Proportion With Culture Conversion in Liquid Media at Weeks 4, 8 and 12

Proportion of participants who have achieved stable culture conversion, defined as two negative sputum cultures, consecutive or not, without an intervening positive culture and/or visits wherein the participant is unable to produce sputum and has no signs of active TB; occurring before or at the week 4, 8, or 12 visit, respectively.

Time frame: Measured at Weeks 4, 8, and 12

Proportion With Culture Conversion in Solid Media at Weeks 4, 8 and 12

Time frame: Measured at Weeks 4, 8, and 12

Cumulative Probability of TB Relapse (by M. Tuberculosis Genotyping)

For participants who had successful culture conversion through the end of study treatment, TB relapse is defined as a recurrence of TB emanating from the same strain as the participant's originally diagnosed TB, which will be determined through whole genome sequencing.

Time frame: Measured from end of treatment (week 12 for Arm 1 and week 26 for Arm2) through Week 86

Proportion of Treatment-emergent Genotypic and Phenotypic Resistance to BCZD

For participants in experimental group only. Minimum Inhibitory Concentration (MIC) values will be evaluated against resistance-associated variants (RAVs) for paired baseline and failure isolates. Frequencies and proportions with phenotypic and/or genotypic resistance to any drug will be reported.

Time frame: Measured through Week 86

Median Time (Days) to Positivity in Liquid Culture

Time to positivity in liquid culture is defined as the days required for a sample to exhibit detectable microbial growth (positive result) in liquid media. A shorter time to positivity indicates a higher concentration of viable microorganisms in the original sample. Participants with a negative liquid culture result were imputed to have the 'best' time to positivity of 43 days (\>42 days), and participants with contaminated culture results were excluded. Sputum samples were collected at weeks 1, 2, 3, 4, 6, and 8 for culture in liquid media.

Time frame: Weeks 1, 2, 3, 4, 6, and 8

Ultra-Short Course Bedaquiline, Clofazimine, Pyrazinamide and Delamanid Versus Standard Therapy for Drug-Susceptible Tuberculosis

Overview

Conditions

Interventions

Eligibility

Locations (2)

Outcomes

Primary Outcomes

Secondary Outcomes