Study Background and Rationale Tuberculosis remains a significant global health challenge, with China ranking among the top three countries with the highest TB burden globally. Current anti-TB treatments for drug-susceptible tuberculosis face major obstacles, primarily poor adherence to long-term (at least 6 months) and complex treatment regimens. Incomplete TB treatment may lead to increased morbidity and mortality, prolonged infectivity, and development of drug resistance.
Recent international studies have demonstrated promising results for shorter treatment regimens. The SimpliciTB study showed that a 4-month short-course regimen containing bedaquiline, moxifloxacin, and pyrazinamide significantly increased 8-week sputum culture clearance rates compared to the standard 6-month regimen. The TRUNCATE-TB study demonstrated that a 2-month regimen containing bedaquiline, isoniazid, and pyrazinamide was non-inferior to standard 6-month treatment. However, bedaquiline-based 4-month short-course regimens have not yet been validated in early-stage studies in the Chinese population.
Study Methodology Treatment Regimens
BZMD Group (Total treatment: 17 weeks):
Intensive phase (8 weeks): Bedaquiline + Pyrazinamide + Moxifloxacin + Delamanid Consolidation phase (9 weeks): Bedaquiline + Moxifloxacin + Delamanid Bedaquiline: 400 mg once daily for 2 weeks, then 200 mg three times weekly for weeks 3-17 Pyrazinamide: Weight-based dosing (1000-2000 mg daily) - intensive phase only Moxifloxacin: 400 mg once daily throughout treatment Delamanid: 100 mg twice daily (200 mg total daily) throughout treatment
BZMH Group (Total treatment: 17 weeks):
Intensive phase (8 weeks): Bedaquiline + Pyrazinamide + Moxifloxacin + Isoniazid Consolidation phase (9 weeks): Bedaquiline + Moxifloxacin + Isoniazid Bedaquiline: Same dosing as BZMD group Pyrazinamide: Weight-based dosing - intensive phase only Moxifloxacin: 400 mg once daily throughout treatment Isoniazid: 300 mg once daily throughout treatment
Standard Control Group (Total treatment: 26 weeks):
Intensive phase (8 weeks): Rifampicin + Isoniazid + Pyrazinamide + Ethambutol Consolidation phase (18 weeks): Rifampicin + Isoniazid
Early Bactericidal Activity Assessment The study employs a rigorous EBA assessment protocol with overnight sputum collections. Subjects must provide at least 10 mL of overnight sputum during each collection cycle. Two pre-treatment overnight sputum specimens are collected on consecutive days before treatment initiation to establish baseline CFU counts. Daily overnight sputum collections continue for the first 14 days of treatment to monitor bactericidal activity.
Pharmacokinetic Substudy A subset of subjects (10-15 per test group) will participate in intensive PK sampling on Day 14, involving 11 blood draws over 24 hours to evaluate steady-state pharmacokinetic characteristics and potential drug-drug interactions between study medications.
Follow-up and Retreatment Criteria All subjects are followed until week 38 post-treatment initiation. For test group subjects who fail to achieve sustained microbiological clearance at end of treatment (week 17) or experience recurrence during follow-up, a standard 6-month HRZE regimen will be re-initiated.
Quality Control Measures
The study implements comprehensive quality assurance including:
* Standardized personnel training for all sites
* Consecutive case enrollment to ensure representativeness
* Dual physician verification of patient information
* Regular monitoring visits by the lead site
* Laboratory quality control with proficiency testing
* Blinded sputum smear rechecking
Statistical Considerations Bactericidal activity will be analyzed using nonlinear mixed-effects models to estimate daily log₁₀ CFU reduction and TTP increases. The study design allows for replacement of subjects who cannot provide adequate sputum specimens to ensure statistical precision. Pharmacokinetic parameters will be compared between test groups using nonparametric methods.
Clinical Significance This study addresses a critical need in tuberculosis treatment by evaluating whether bedaquiline-based short-course regimens can reduce treatment duration from 6 months to 4 months while maintaining efficacy. Successful results could lead to improved treatment adherence, reduced healthcare costs, and decreased risk of drug resistance development. The study specifically focuses on the Chinese population, addressing potential pharmacokinetic and genetic variations that may influence treatment outcomes.
The early bactericidal activity endpoint provides rapid assessment of regimen efficacy, allowing for early identification of promising combinations before larger, longer-term studies. This approach accelerates the development of improved tuberculosis treatment regimens while maintaining rigorous safety monitoring.
